Added Tests

Assets/Mirror/Tests.meta

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Assets/Mirror/Tests/Common.meta

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Assets/Mirror/Tests/Common/Castle.Core.dll.meta

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Assets/Mirror/Tests/Common/ClientSceneTestsBase.cs

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+using System;
+using NUnit.Framework;
+using UnityEditor;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+
+    /// <summary>
+    /// Used by both runtime and edit time tests
+    /// </summary>
+    [TestFixture]
+    public abstract class ClientSceneTestsBase : MirrorEditModeTest
+    {
+        // use guid to find asset so that the path does not matter
+        protected const string ValidPrefabAssetGuid = "33169286da0313d45ab5bfccc6cf3775";
+        protected const string PrefabWithChildrenAssetGuid = "a78e009e3f2dee44e8859516974ede43";
+        protected const string InvalidPrefabAssetGuid = "78f0a3f755d35324e959f3ecdd993fb0";
+        // random guid, not used anywhere
+        protected const string AnotherGuidString = "5794128cdfda04542985151f82990d05";
+
+        protected GameObject validPrefab;
+        protected NetworkIdentity validPrefabNetworkIdentity;
+        protected GameObject prefabWithChildren;
+        protected GameObject invalidPrefab;
+        protected Guid validPrefabGuid;
+        protected Guid anotherGuid;
+
+        static GameObject LoadPrefab(string guid)
+        {
+            return AssetDatabase.LoadAssetAtPath<GameObject>(AssetDatabase.GUIDToAssetPath(guid));
+        }
+
+        [OneTimeSetUp]
+        public void OneTimeSetUp()
+        {
+            validPrefab = LoadPrefab(ValidPrefabAssetGuid);
+            validPrefabNetworkIdentity = validPrefab.GetComponent<NetworkIdentity>();
+            prefabWithChildren = LoadPrefab(PrefabWithChildrenAssetGuid);
+            invalidPrefab = LoadPrefab(InvalidPrefabAssetGuid);
+            validPrefabGuid = new Guid(ValidPrefabAssetGuid);
+            anotherGuid = new Guid(AnotherGuidString);
+        }
+
+        [TearDown]
+        public override void TearDown()
+        {
+            // reset asset id in case they are changed by tests
+            validPrefabNetworkIdentity.assetId = validPrefabGuid;
+
+            base.TearDown();
+        }
+
+        [OneTimeTearDown]
+        public void OneTimeTearDown()
+        {
+            validPrefab = null;
+            prefabWithChildren = null;
+            invalidPrefab = null;
+        }
+    }
+}

Assets/Mirror/Tests/Common/ClientSceneTestsBase.cs.meta

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Assets/Mirror/Tests/Common/ClientSceneTests_RegisterPrefabBase.cs

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+using System;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    /// <summary>
+    /// Used by both runtime and edit time tests
+    /// </summary>
+    [TestFixture]
+    public abstract class ClientSceneTests_RegisterPrefabBase : ClientSceneTestsBase
+    {
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab, false)]
+        [TestCase(RegisterPrefabOverload.Prefab_NewAssetId, true)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate, false)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId, true)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate, false)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId, true)]
+        public void CheckOverloadWithAssetId(RegisterPrefabOverload overload, bool expected)
+        {
+            // test to make sure OverloadWithAssetId correctly works with flags
+            Assert.That(OverloadWithAssetId(overload), Is.EqualTo(expected));
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab, false)]
+        [TestCase(RegisterPrefabOverload.Prefab_NewAssetId, false)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate, true)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId, true)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate, true)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId, true)]
+        public void CheckOverloadWithHandler(RegisterPrefabOverload overload, bool expected)
+        {
+            // test to make sure OverloadWithHandler correctly works with flags
+            Assert.That(OverloadWithHandler(overload), Is.EqualTo(expected));
+        }
+
+        /// <summary>
+        /// Allows TestCases to call different overloads for RegisterPrefab.
+        /// Without this we would need duplicate tests for each overload
+        /// </summary>
+        [Flags]
+        public enum RegisterPrefabOverload
+        {
+            Prefab = 1,
+            Prefab_NewAssetId = 2,
+            Prefab_SpawnDelegate = 4,
+            Prefab_SpawnDelegate_NewAssetId = 8,
+            Prefab_SpawnHandlerDelegate = 16,
+            Prefab_SpawnHandlerDelegate_NewAssetId = 32,
+
+            WithAssetId = Prefab_NewAssetId | Prefab_SpawnDelegate_NewAssetId | Prefab_SpawnHandlerDelegate_NewAssetId,
+            WithHandler = Prefab_SpawnDelegate | Prefab_SpawnDelegate_NewAssetId | Prefab_SpawnHandlerDelegate | Prefab_SpawnHandlerDelegate_NewAssetId
+        }
+
+        protected static bool OverloadWithAssetId(RegisterPrefabOverload overload)
+        {
+            return (overload & RegisterPrefabOverload.WithAssetId) != 0;
+        }
+
+        protected static bool OverloadWithHandler(RegisterPrefabOverload overload)
+        {
+            return (overload & RegisterPrefabOverload.WithHandler) != 0;
+        }
+
+        protected void CallRegisterPrefab(GameObject prefab, RegisterPrefabOverload overload)
+        {
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            SpawnHandlerDelegate spawnHandlerDelegate = new SpawnHandlerDelegate(x => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            switch (overload)
+            {
+                case RegisterPrefabOverload.Prefab:
+                    NetworkClient.RegisterPrefab(prefab);
+                    break;
+                case RegisterPrefabOverload.Prefab_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, anotherGuid);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnDelegate:
+                    NetworkClient.RegisterPrefab(prefab, spawnHandler, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, anotherGuid, spawnHandler, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate:
+                    NetworkClient.RegisterPrefab(prefab, spawnHandlerDelegate, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, anotherGuid, spawnHandlerDelegate, unspawnHandler);
+                    break;
+
+                default:
+                    Debug.LogError("Overload not found");
+                    break;
+            }
+        }
+
+        protected void CallRegisterPrefab(GameObject prefab, RegisterPrefabOverload overload, Guid guid)
+        {
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            SpawnHandlerDelegate spawnHandlerDelegate = new SpawnHandlerDelegate(x => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            switch (overload)
+            {
+                case RegisterPrefabOverload.Prefab_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, guid);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, guid, spawnHandler, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, guid, spawnHandlerDelegate, unspawnHandler);
+                    break;
+
+                case RegisterPrefabOverload.Prefab:
+                case RegisterPrefabOverload.Prefab_SpawnDelegate:
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate:
+                    Debug.LogError("Overload did not have guid parameter");
+                    break;
+                default:
+                    Debug.LogError("Overload not found");
+                    break;
+            }
+        }
+
+        protected void CallRegisterPrefab(GameObject prefab, RegisterPrefabOverload overload, SpawnDelegate spawnHandler)
+        {
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            switch (overload)
+            {
+                case RegisterPrefabOverload.Prefab_SpawnDelegate:
+                    NetworkClient.RegisterPrefab(prefab, spawnHandler, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, anotherGuid, spawnHandler, unspawnHandler);
+                    break;
+
+                case RegisterPrefabOverload.Prefab:
+                case RegisterPrefabOverload.Prefab_NewAssetId:
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate:
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId:
+                    Debug.LogError("Overload did not have SpawnDelegate parameter");
+                    break;
+                default:
+                    Debug.LogError("Overload not found");
+                    break;
+            }
+        }
+
+        protected void CallRegisterPrefab(GameObject prefab, RegisterPrefabOverload overload, SpawnHandlerDelegate spawnHandlerDelegate)
+        {
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            switch (overload)
+            {
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate:
+                    NetworkClient.RegisterPrefab(prefab, spawnHandlerDelegate, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, anotherGuid, spawnHandlerDelegate, unspawnHandler);
+                    break;
+
+                case RegisterPrefabOverload.Prefab:
+                case RegisterPrefabOverload.Prefab_NewAssetId:
+                case RegisterPrefabOverload.Prefab_SpawnDelegate:
+                case RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId:
+                    Debug.LogError("Overload did not have SpawnHandlerDelegate parameter");
+                    break;
+                default:
+                    Debug.LogError("Overload not found");
+                    break;
+            }
+        }
+
+        protected void CallRegisterPrefab(GameObject prefab, RegisterPrefabOverload overload, UnSpawnDelegate unspawnHandler)
+        {
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            SpawnHandlerDelegate spawnHandlerDelegate = new SpawnHandlerDelegate(x => null);
+
+            switch (overload)
+            {
+
+                case RegisterPrefabOverload.Prefab_SpawnDelegate:
+                    NetworkClient.RegisterPrefab(prefab, spawnHandler, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, anotherGuid, spawnHandler, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate:
+                    NetworkClient.RegisterPrefab(prefab, spawnHandlerDelegate, unspawnHandler);
+                    break;
+                case RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId:
+                    NetworkClient.RegisterPrefab(prefab, anotherGuid, spawnHandlerDelegate, unspawnHandler);
+                    break;
+
+                case RegisterPrefabOverload.Prefab:
+                case RegisterPrefabOverload.Prefab_NewAssetId:
+                    Debug.LogError("Overload did not have UnSpawnDelegate parameter");
+                    break;
+                default:
+                    Debug.LogError("Overload not found");
+                    break;
+            }
+        }
+
+        protected Guid GuidForOverload(RegisterPrefabOverload overload) => OverloadWithAssetId(overload) ? anotherGuid : validPrefabGuid;
+    }
+}

Assets/Mirror/Tests/Common/ClientSceneTests_RegisterPrefabBase.cs.meta

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Assets/Mirror/Tests/Common/FakeNetworkConnection.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace Mirror.Tests
+{
+    public class FakeNetworkConnection : NetworkConnectionToClient
+    {
+        public FakeNetworkConnection() : base(1) {}
+        public override string address => "Test";
+        public override void Disconnect() {}
+        internal override void Send(ArraySegment<byte> segment, int channelId = 0) {}
+    }
+}

Assets/Mirror/Tests/Common/FakeNetworkConnection.cs.meta

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Assets/Mirror/Tests/Common/MemoryTransport.cs

@@ -0,0 +1,208 @@
+// memory transport for easier testing
+// note: file needs to be outside of Editor folder, otherwise AddComponent
+//       can't be called with MemoryTransport
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public class MemoryTransport : Transport
+    {
+        public enum EventType { Connected, Data, Disconnected }
+        public struct Message
+        {
+            public int connectionId;
+            public EventType eventType;
+            public byte[] data;
+            public Message(int connectionId, EventType eventType, byte[] data)
+            {
+                this.connectionId = connectionId;
+                this.eventType = eventType;
+                this.data = data;
+            }
+        }
+
+        bool clientConnected;
+        public Queue<Message> clientIncoming = new Queue<Message>();
+        bool serverActive;
+        public Queue<Message> serverIncoming = new Queue<Message>();
+
+        public override bool Available() => true;
+        // limit max size to something reasonable so pool doesn't allocate
+        // int.MaxValue = 2GB each time.
+        public override int GetMaxPacketSize(int channelId) => ushort.MaxValue;
+        // 1400 max batch size
+        // -> need something != GetMaxPacketSize for testing
+        // -> MTU aka 1400 is used a lot anyway
+        public override int GetBatchThreshold(int channelId) => 1400;
+        public override void Shutdown() {}
+        public override bool ClientConnected() => clientConnected;
+        public override void ClientConnect(string address)
+        {
+            // only if server is running
+            if (serverActive)
+            {
+                // add server connected message with connId=1 because 0 is reserved
+                serverIncoming.Enqueue(new Message(1, EventType.Connected, null));
+
+                // add client connected message
+                clientIncoming.Enqueue(new Message(0, EventType.Connected, null));
+
+                clientConnected = true;
+            }
+        }
+        public override void ClientSend(ArraySegment<byte> segment, int channelId)
+        {
+            // only  if client connected
+            if (clientConnected)
+            {
+                // a real transport fails for > max sized messages.
+                // mirror checks it, but let's guarantee that we catch > max
+                // sized message send attempts just like a real transport would.
+                // => helps to cover packet size issues i.e. for timestamp
+                //    batching tests
+                int max = GetMaxPacketSize(channelId);
+                if (segment.Count > max)
+                    throw new Exception($"MemoryTransport ClientSend of {segment.Count} bytes exceeds max of {max} bytes");
+
+                // copy segment data because it's only valid until return
+                byte[] data = new byte[segment.Count];
+                Array.Copy(segment.Array, segment.Offset, data, 0, segment.Count);
+
+                // add server data message with connId=1 because 0 is reserved
+                serverIncoming.Enqueue(new Message(1, EventType.Data, data));
+            }
+        }
+        public override void ClientDisconnect()
+        {
+            // only  if client connected
+            if (clientConnected)
+            {
+                // clear all pending messages that we may have received.
+                // over the wire, we wouldn't receive any more pending messages
+                // ether after calling disconnect.
+                clientIncoming.Clear();
+
+                // add server disconnected message with connId=1 because 0 is reserved
+                serverIncoming.Enqueue(new Message(1, EventType.Disconnected, null));
+
+                // add client disconnected message
+                clientIncoming.Enqueue(new Message(0, EventType.Disconnected, null));
+
+                // not connected anymore
+                clientConnected = false;
+            }
+        }
+        // messages should always be processed in early update
+        public override void ClientEarlyUpdate()
+        {
+            // note: process even if not connected because when calling
+            // Disconnect, we add a Disconnected event which still needs to be
+            // processed here.
+            while (clientIncoming.Count > 0)
+            {
+                Message message = clientIncoming.Dequeue();
+                switch (message.eventType)
+                {
+                    case EventType.Connected:
+                        Debug.Log("MemoryTransport Client Message: Connected");
+                        OnClientConnected.Invoke();
+                        break;
+                    case EventType.Data:
+                        Debug.Log($"MemoryTransport Client Message: Data: {BitConverter.ToString(message.data)}");
+                        OnClientDataReceived.Invoke(new ArraySegment<byte>(message.data), 0);
+                        break;
+                    case EventType.Disconnected:
+                        Debug.Log("MemoryTransport Client Message: Disconnected");
+                        OnClientDisconnected.Invoke();
+                        break;
+                }
+            }
+        }
+
+        public override bool ServerActive() => serverActive;
+        public override Uri ServerUri() => throw new NotImplementedException();
+        public override void ServerStart() { serverActive = true; }
+        public override void ServerSend(int connectionId, ArraySegment<byte> segment, int channelId)
+        {
+            // only if server is running and client is connected
+            if (serverActive && clientConnected)
+            {
+                // a real transport fails for > max sized messages.
+                // mirror checks it, but let's guarantee that we catch > max
+                // sized message send attempts just like a real transport would.
+                // => helps to cover packet size issues i.e. for timestamp
+                //    batching tests
+                int max = GetMaxPacketSize(channelId);
+                if (segment.Count > max)
+                    throw new Exception($"MemoryTransport ServerSend of {segment.Count} bytes exceeds max of {max} bytes");
+
+                // copy segment data because it's only valid until return
+                byte[] data = new byte[segment.Count];
+                Array.Copy(segment.Array, segment.Offset, data, 0, segment.Count);
+
+                // add client data message
+                clientIncoming.Enqueue(new Message(0, EventType.Data, data));
+            }
+        }
+
+        public override void ServerDisconnect(int connectionId)
+        {
+            // clear all pending messages that we may have received.
+            // over the wire, we wouldn't receive any more pending messages
+            // ether after calling disconnect.
+            serverIncoming.Clear();
+
+            // add client disconnected message with connectionId
+            clientIncoming.Enqueue(new Message(connectionId, EventType.Disconnected, null));
+
+            // add server disconnected message with connectionId
+            serverIncoming.Enqueue(new Message(connectionId, EventType.Disconnected, null));
+
+            // not active anymore
+            serverActive = false;
+        }
+
+        public override string ServerGetClientAddress(int connectionId) => string.Empty;
+        public override void ServerStop()
+        {
+            // clear all pending messages that we may have received.
+            // over the wire, we wouldn't receive any more pending messages
+            // ether after calling stop.
+            serverIncoming.Clear();
+
+            // add client disconnected message
+            clientIncoming.Enqueue(new Message(0, EventType.Disconnected, null));
+
+            // add server disconnected message with connId=1 because 0 is reserved
+            serverIncoming.Enqueue(new Message(1, EventType.Disconnected, null));
+
+            // not active anymore
+            serverActive = false;
+        }
+        // messages should always be processed in early update
+        public override void ServerEarlyUpdate()
+        {
+            while (serverIncoming.Count > 0)
+            {
+                Message message = serverIncoming.Dequeue();
+                switch (message.eventType)
+                {
+                    case EventType.Connected:
+                        Debug.Log("MemoryTransport Server Message: Connected");
+                        OnServerConnected.Invoke(message.connectionId);
+                        break;
+                    case EventType.Data:
+                        Debug.Log($"MemoryTransport Server Message: Data: {BitConverter.ToString(message.data)}");
+                        OnServerDataReceived.Invoke(message.connectionId, new ArraySegment<byte>(message.data), 0);
+                        break;
+                    case EventType.Disconnected:
+                        Debug.Log("MemoryTransport Server Message: Disconnected");
+                        OnServerDisconnected.Invoke(message.connectionId);
+                        break;
+                }
+            }
+        }
+    }
+}

Assets/Mirror/Tests/Common/MemoryTransport.cs.meta

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Assets/Mirror/Tests/Common/Mirror.Tests.Common.asmdef

@@ -0,0 +1,16 @@
+{
+    "name": "Mirror.Tests.Common",
+    "references": [
+        "Mirror"
+    ],
+    "optionalUnityReferences": [
+        "TestAssemblies"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": []
+}

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Assets/Mirror/Tests/Common/MirrorEditModeTest.cs

@@ -0,0 +1,14 @@
+// base class for networking tests to make things easier.
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public abstract class MirrorEditModeTest : MirrorTest
+    {
+        [SetUp]
+        public override void SetUp() => base.SetUp();
+
+        [TearDown]
+        public override void TearDown() => base.TearDown();
+    }
+}

Assets/Mirror/Tests/Common/MirrorEditModeTest.cs.meta

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+  assetBundleVariant: 

Assets/Mirror/Tests/Common/MirrorPlayModeTest.cs

@@ -0,0 +1,27 @@
+// base class for networking tests to make things easier.
+using System.Collections;
+using UnityEngine.TestTools;
+
+namespace Mirror.Tests
+{
+    public abstract class MirrorPlayModeTest : MirrorTest
+    {
+        // when overwriting, call it like this:
+        //   yield return base.UnitySetUp();
+        [UnitySetUp]
+        public virtual IEnumerator UnitySetUp()
+        {
+            base.SetUp();
+            yield return null;
+        }
+
+        // when overwriting, call it like this:
+        //   yield return base.UnityTearDown();
+        [UnityTearDown]
+        public virtual IEnumerator UnityTearDown()
+        {
+            base.TearDown();
+            yield return null;
+        }
+    }
+}

Assets/Mirror/Tests/Common/MirrorPlayModeTest.cs.meta

@@ -0,0 +1,11 @@
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+guid: be3f9e24bcdb748728f846e88eea29f3
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Common/MirrorTest.cs

@@ -0,0 +1,557 @@
+// base class for networking tests to make things easier.
+using System.Collections.Generic;
+using System.Linq;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    // inherited by MirrorEditModeTest / MirrorPlayModeTest
+    // to call SetUp/TearDown by [SetUp]/[UnitySetUp] as needed
+    public abstract class MirrorTest
+    {
+        // keep track of networked GameObjects so we don't have to clean them
+        // up manually each time.
+        // CreateNetworked() adds to the list automatically.
+        public List<GameObject> instantiated;
+
+        // we usually need the memory transport
+        public MemoryTransport transport;
+
+        public virtual void SetUp()
+        {
+            instantiated = new List<GameObject>();
+
+            // need a transport to send & receive
+            Transport.activeTransport = transport = new GameObject().AddComponent<MemoryTransport>();
+        }
+
+        public virtual void TearDown()
+        {
+            NetworkClient.Shutdown();
+            NetworkServer.Shutdown();
+
+            // some tests might modify NetworkServer.connections without ever
+            // starting the server.
+            // NetworkServer.Shutdown() only clears connections if it was started.
+            // so let's do it manually for proper test cleanup here.
+            NetworkServer.connections.Clear();
+
+            foreach (GameObject go in instantiated)
+                if (go != null)
+                    GameObject.DestroyImmediate(go);
+
+            GameObject.DestroyImmediate(transport.gameObject);
+            Transport.activeTransport = null;
+        }
+
+        // create a tracked GameObject for tests without Networkidentity
+        // add to tracker list if needed (useful for cleanups afterwards)
+        protected void CreateGameObject(out GameObject go)
+        {
+            go = new GameObject();
+            // track
+            instantiated.Add(go);
+        }
+
+        // create GameObject + MonoBehaviour<T>
+        // add to tracker list if needed (useful for cleanups afterwards)
+        protected void CreateGameObject<T>(out GameObject go, out T component)
+            where T : MonoBehaviour
+        {
+            CreateGameObject(out go);
+            component = go.AddComponent<T>();
+        }
+
+        // create GameObject + NetworkIdentity
+        // add to tracker list if needed (useful for cleanups afterwards)
+        protected void CreateNetworked(out GameObject go, out NetworkIdentity identity)
+        {
+            go = new GameObject();
+            identity = go.AddComponent<NetworkIdentity>();
+            // Awake is only called in play mode.
+            // call manually for initialization.
+            identity.Awake();
+            // track
+            instantiated.Add(go);
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour<T>
+        // add to tracker list if needed (useful for cleanups afterwards)
+        protected void CreateNetworked<T>(out GameObject go, out NetworkIdentity identity, out T component)
+            where T : NetworkBehaviour
+        {
+            go = new GameObject();
+            identity = go.AddComponent<NetworkIdentity>();
+            component = go.AddComponent<T>();
+            // always set syncinterval = 0 for immediate testing
+            component.syncInterval = 0;
+            // Awake is only called in play mode.
+            // call manually for initialization.
+            identity.Awake();
+            // track
+            instantiated.Add(go);
+        }
+
+        // create GameObject + NetworkIdentity + 2x NetworkBehaviour<T>
+        // add to tracker list if needed (useful for cleanups afterwards)
+        protected void CreateNetworked<T, U>(out GameObject go, out NetworkIdentity identity, out T componentA, out U componentB)
+            where T : NetworkBehaviour
+            where U : NetworkBehaviour
+        {
+            go = new GameObject();
+            identity = go.AddComponent<NetworkIdentity>();
+            componentA = go.AddComponent<T>();
+            componentB = go.AddComponent<U>();
+            // always set syncinterval = 0 for immediate testing
+            componentA.syncInterval = 0;
+            componentB.syncInterval = 0;
+            // Awake is only called in play mode.
+            // call manually for initialization.
+            identity.Awake();
+            // track
+            instantiated.Add(go);
+        }
+
+        // create GameObject + NetworkIdentity + 2x NetworkBehaviour<T>
+        // add to tracker list if needed (useful for cleanups afterwards)
+        protected void CreateNetworked<T, U, V>(out GameObject go, out NetworkIdentity identity, out T componentA, out U componentB, out V componentC)
+            where T : NetworkBehaviour
+            where U : NetworkBehaviour
+            where V : NetworkBehaviour
+        {
+            go = new GameObject();
+            identity = go.AddComponent<NetworkIdentity>();
+            componentA = go.AddComponent<T>();
+            componentB = go.AddComponent<U>();
+            componentC = go.AddComponent<V>();
+            // always set syncinterval = 0 for immediate testing
+            componentA.syncInterval = 0;
+            componentB.syncInterval = 0;
+            componentC.syncInterval = 0;
+            // Awake is only called in play mode.
+            // call manually for initialization.
+            identity.Awake();
+            // track
+            instantiated.Add(go);
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        protected void CreateNetworkedAndSpawn(out GameObject go, out NetworkIdentity identity, NetworkConnection ownerConnection = null)
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            CreateNetworked(out go, out identity);
+
+            // spawn
+            NetworkServer.Spawn(go, ownerConnection);
+            ProcessMessages();
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        // => returns objects from client and from server.
+        //    will be same in host mode.
+        protected void CreateNetworkedAndSpawn(
+            out GameObject serverGO, out NetworkIdentity serverIdentity,
+            out GameObject clientGO, out NetworkIdentity clientIdentity,
+            NetworkConnection ownerConnection = null)
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create one on server, one on client
+            // (spawning has to find it on client, it doesn't create it)
+            CreateNetworked(out serverGO, out serverIdentity);
+            CreateNetworked(out clientGO, out clientIdentity);
+
+            // give both a scene id and register it on client for spawnables
+            clientIdentity.sceneId = serverIdentity.sceneId = (ulong)serverGO.GetHashCode();
+            NetworkClient.spawnableObjects[clientIdentity.sceneId] = clientIdentity;
+
+            // spawn
+            NetworkServer.Spawn(serverGO, ownerConnection);
+            ProcessMessages();
+
+            // make sure the client really spawned it.
+            Assert.That(NetworkClient.spawned.ContainsKey(serverIdentity.netId));
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        protected void CreateNetworkedAndSpawn<T>(out GameObject go, out NetworkIdentity identity, out T component, NetworkConnection ownerConnection = null)
+            where T : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            CreateNetworked(out go, out identity, out component);
+
+            // spawn
+            NetworkServer.Spawn(go, ownerConnection);
+            ProcessMessages();
+
+            // double check that we have authority if we passed an owner connection
+            if (ownerConnection != null)
+                Debug.Assert(component.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        // => returns objects from client and from server.
+        //    will be same in host mode.
+        protected void CreateNetworkedAndSpawn<T>(
+            out GameObject serverGO, out NetworkIdentity serverIdentity, out T serverComponent,
+            out GameObject clientGO, out NetworkIdentity clientIdentity, out T clientComponent,
+            NetworkConnection ownerConnection = null)
+            where T : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create one on server, one on client
+            // (spawning has to find it on client, it doesn't create it)
+            CreateNetworked(out serverGO, out serverIdentity, out serverComponent);
+            CreateNetworked(out clientGO, out clientIdentity, out clientComponent);
+
+            // give both a scene id and register it on client for spawnables
+            clientIdentity.sceneId = serverIdentity.sceneId = (ulong)serverGO.GetHashCode();
+            NetworkClient.spawnableObjects[clientIdentity.sceneId] = clientIdentity;
+
+            // spawn
+            NetworkServer.Spawn(serverGO, ownerConnection);
+            ProcessMessages();
+
+            // double check that we have authority if we passed an owner connection
+            if (ownerConnection != null)
+                Debug.Assert(serverComponent.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+
+            // make sure the client really spawned it.
+            Assert.That(NetworkClient.spawned.ContainsKey(serverIdentity.netId));
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        protected void CreateNetworkedAndSpawn<T, U>(out GameObject go, out NetworkIdentity identity, out T componentA, out U componentB, NetworkConnection ownerConnection = null)
+            where T : NetworkBehaviour
+            where U : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            CreateNetworked(out go, out identity, out componentA, out componentB);
+
+            // spawn
+            NetworkServer.Spawn(go, ownerConnection);
+            ProcessMessages();
+
+            // double check that we have authority if we passed an owner connection
+            if (ownerConnection != null)
+            {
+                Debug.Assert(componentA.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+                Debug.Assert(componentB.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+            }
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        // => returns objects from client and from server.
+        //    will be same in host mode.
+        protected void CreateNetworkedAndSpawn<T, U>(
+            out GameObject serverGO, out NetworkIdentity serverIdentity, out T serverComponentA, out U serverComponentB,
+            out GameObject clientGO, out NetworkIdentity clientIdentity, out T clientComponentA, out U clientComponentB,
+            NetworkConnection ownerConnection = null)
+            where T : NetworkBehaviour
+            where U : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create one on server, one on client
+            // (spawning has to find it on client, it doesn't create it)
+            CreateNetworked(out serverGO, out serverIdentity, out serverComponentA, out serverComponentB);
+            CreateNetworked(out clientGO, out clientIdentity, out clientComponentA, out clientComponentB);
+
+            // give both a scene id and register it on client for spawnables
+            clientIdentity.sceneId = serverIdentity.sceneId = (ulong)serverGO.GetHashCode();
+            NetworkClient.spawnableObjects[clientIdentity.sceneId] = clientIdentity;
+
+            // spawn
+            NetworkServer.Spawn(serverGO, ownerConnection);
+            ProcessMessages();
+
+            // double check that we have authority if we passed an owner connection
+            if (ownerConnection != null)
+            {
+                Debug.Assert(serverComponentA.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+                Debug.Assert(serverComponentB.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+            }
+
+            // make sure the client really spawned it.
+            Assert.That(NetworkClient.spawned.ContainsKey(serverIdentity.netId));
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        protected void CreateNetworkedAndSpawn<T, U, V>(out GameObject go, out NetworkIdentity identity, out T componentA, out U componentB, out V componentC, NetworkConnection ownerConnection = null)
+            where T : NetworkBehaviour
+            where U : NetworkBehaviour
+            where V : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            CreateNetworked(out go, out identity, out componentA, out componentB, out componentC);
+
+            // spawn
+            NetworkServer.Spawn(go, ownerConnection);
+            ProcessMessages();
+
+            // double check that we have authority if we passed an owner connection
+            if (ownerConnection != null)
+            {
+                Debug.Assert(componentA.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+                Debug.Assert(componentB.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+                Debug.Assert(componentC.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+            }
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN
+        // => ownerConnection can be NetworkServer.localConnection if needed.
+        // => returns objects from client and from server.
+        //    will be same in host mode.
+        protected void CreateNetworkedAndSpawn<T, U, V>(
+            out GameObject serverGO, out NetworkIdentity serverIdentity, out T serverComponentA, out U serverComponentB, out V serverComponentC,
+            out GameObject clientGO, out NetworkIdentity clientIdentity, out T clientComponentA, out U clientComponentB, out V clientComponentC,
+            NetworkConnection ownerConnection = null)
+            where T : NetworkBehaviour
+            where U : NetworkBehaviour
+            where V : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create one on server, one on client
+            // (spawning has to find it on client, it doesn't create it)
+            CreateNetworked(out serverGO, out serverIdentity, out serverComponentA, out serverComponentB, out serverComponentC);
+            CreateNetworked(out clientGO, out clientIdentity, out clientComponentA, out clientComponentB, out clientComponentC);
+
+            // give both a scene id and register it on client for spawnables
+            clientIdentity.sceneId = serverIdentity.sceneId = (ulong)serverGO.GetHashCode();
+            NetworkClient.spawnableObjects[clientIdentity.sceneId] = clientIdentity;
+
+            // spawn
+            NetworkServer.Spawn(serverGO, ownerConnection);
+            ProcessMessages();
+
+            // double check that we have authority if we passed an owner connection
+            if (ownerConnection != null)
+            {
+                Debug.Assert(serverComponentA.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+                Debug.Assert(serverComponentB.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+                Debug.Assert(serverComponentC.hasAuthority == true, $"Behaviour Had Wrong Authority when spawned, This means that the test is broken and will give the wrong results");
+            }
+
+            // make sure the client really spawned it.
+            Assert.That(NetworkClient.spawned.ContainsKey(serverIdentity.netId));
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN PLAYER.
+        // often times, we really need a player object for the client to receive
+        // certain messages.
+        protected void CreateNetworkedAndSpawnPlayer(out GameObject go, out NetworkIdentity identity, NetworkConnection ownerConnection)
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create a networked object
+            CreateNetworked(out go, out identity);
+
+            // add as player & process spawn message on client.
+            NetworkServer.AddPlayerForConnection(ownerConnection, go);
+            ProcessMessages();
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN PLAYER.
+        // often times, we really need a player object for the client to receive
+        // certain messages.
+        // => returns objects from client and from server.
+        //    will be same in host mode.
+        protected void CreateNetworkedAndSpawnPlayer(
+            out GameObject serverGO, out NetworkIdentity serverIdentity,
+            out GameObject clientGO, out NetworkIdentity clientIdentity,
+            NetworkConnection ownerConnection)
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create one on server, one on client
+            // (spawning has to find it on client, it doesn't create it)
+            CreateNetworked(out serverGO, out serverIdentity);
+            CreateNetworked(out clientGO, out clientIdentity);
+
+            // give both a scene id and register it on client for spawnables
+            clientIdentity.sceneId = serverIdentity.sceneId = (ulong)serverGO.GetHashCode();
+            NetworkClient.spawnableObjects[clientIdentity.sceneId] = clientIdentity;
+
+            // add as player & process spawn message on client.
+            NetworkServer.AddPlayerForConnection(ownerConnection, serverGO);
+            ProcessMessages();
+
+            // make sure the client really spawned it.
+            Assert.That(NetworkClient.spawned.ContainsKey(serverIdentity.netId));
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN PLAYER.
+        // often times, we really need a player object for the client to receive
+        // certain messages.
+        protected void CreateNetworkedAndSpawnPlayer<T>(out GameObject go, out NetworkIdentity identity, out T component, NetworkConnection ownerConnection)
+            where T : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create a networked object
+            CreateNetworked(out go, out identity, out component);
+
+            // add as player & process spawn message on client.
+            NetworkServer.AddPlayerForConnection(ownerConnection, go);
+            ProcessMessages();
+        }
+
+        // create GameObject + NetworkIdentity + NetworkBehaviour & SPAWN PLAYER.
+        // often times, we really need a player object for the client to receive
+        // certain messages.
+        // => returns objects from client and from server.
+        //    will be same in host mode.
+        protected void CreateNetworkedAndSpawnPlayer<T>(
+            out GameObject serverGO, out NetworkIdentity serverIdentity, out T serverComponent,
+            out GameObject clientGO, out NetworkIdentity clientIdentity, out T clientComponent,
+            NetworkConnection ownerConnection)
+            where T : NetworkBehaviour
+        {
+            // server & client need to be active before spawning
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // create one on server, one on client
+            // (spawning has to find it on client, it doesn't create it)
+            CreateNetworked(out serverGO, out serverIdentity, out serverComponent);
+            CreateNetworked(out clientGO, out clientIdentity, out clientComponent);
+
+            // give both a scene id and register it on client for spawnables
+            clientIdentity.sceneId = serverIdentity.sceneId = (ulong)serverGO.GetHashCode();
+            NetworkClient.spawnableObjects[clientIdentity.sceneId] = clientIdentity;
+
+            // add as player & process spawn message on client.
+            NetworkServer.AddPlayerForConnection(ownerConnection, serverGO);
+            ProcessMessages();
+
+            // make sure the client really spawned it.
+            Assert.That(NetworkClient.spawned.ContainsKey(serverIdentity.netId));
+        }
+
+        // fully connect client to local server
+        // gives out the server's connection to client for convenience if needed
+        protected void ConnectClientBlocking(out NetworkConnectionToClient connectionToClient)
+        {
+            NetworkClient.Connect("127.0.0.1");
+            UpdateTransport();
+
+            Assert.That(NetworkServer.connections.Count, Is.EqualTo(1));
+            connectionToClient = NetworkServer.connections.Values.First();
+        }
+
+        // fully connect client to local server & authenticate
+        protected void ConnectClientBlockingAuthenticated(out NetworkConnectionToClient connectionToClient)
+        {
+            ConnectClientBlocking(out connectionToClient);
+
+            // authenticate server & client connections
+            connectionToClient.isAuthenticated = true;
+            NetworkClient.connection.isAuthenticated = true;
+        }
+
+        // fully connect client to local server & authenticate & set read
+        protected void ConnectClientBlockingAuthenticatedAndReady(out NetworkConnectionToClient connectionToClient)
+        {
+            ConnectClientBlocking(out connectionToClient);
+
+            // authenticate server & client connections
+            connectionToClient.isAuthenticated = true;
+            NetworkClient.connection.isAuthenticated = true;
+
+            // set ready
+            NetworkClient.Ready();
+            ProcessMessages();
+            Assert.That(connectionToClient.isReady, Is.True);
+        }
+
+        // fully connect HOST client to local server
+        // sets NetworkServer.localConnection / NetworkClient.connection.
+        protected void ConnectHostClientBlocking()
+        {
+            NetworkClient.ConnectHost();
+            NetworkClient.ConnectLocalServer();
+            UpdateTransport();
+            Assert.That(NetworkServer.connections.Count, Is.EqualTo(1));
+        }
+
+        // fully connect client to local server & authenticate & set read
+        protected void ConnectHostClientBlockingAuthenticatedAndReady()
+        {
+            ConnectHostClientBlocking();
+
+            // authenticate server & client connections
+            NetworkServer.localConnection.isAuthenticated = true;
+            NetworkClient.connection.isAuthenticated = true;
+
+            // set ready
+            NetworkClient.Ready();
+            ProcessMessages();
+            Assert.That(NetworkServer.localConnection.isReady, Is.True);
+        }
+
+        protected void UpdateTransport()
+        {
+            transport.ClientEarlyUpdate();
+            transport.ServerEarlyUpdate();
+        }
+
+        protected void ProcessMessages()
+        {
+            // server & client need to be active
+            Debug.Assert(NetworkClient.active, "NetworkClient needs to be active before spawning.");
+            Debug.Assert(NetworkServer.active, "NetworkServer needs to be active before spawning.");
+
+            // update server & client so batched messages are flushed
+            NetworkClient.NetworkLateUpdate();
+            NetworkServer.NetworkLateUpdate();
+
+            // update transport so sent messages are received
+            UpdateTransport();
+        }
+
+        // helper function to create local connection pair
+        protected void CreateLocalConnectionPair(out LocalConnectionToClient connectionToClient, out LocalConnectionToServer connectionToServer)
+        {
+            connectionToClient = new LocalConnectionToClient();
+            connectionToServer = new LocalConnectionToServer();
+            connectionToClient.connectionToServer = connectionToServer;
+            connectionToServer.connectionToClient = connectionToClient;
+        }
+    }
+}

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+    second:
+      enabled: 0
+      settings:
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+      Editor: Editor
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+    second:
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+      settings:
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+  - first:
+      Windows Store Apps: WindowsStoreApps
+    second:
+      enabled: 0
+      settings:
+        CPU: AnyCPU
+  - first:
+      iPhone: iOS
+    second:
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+      settings:
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+  - first:
+      Facebook: Win
+    second:
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+    second:
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+    second:
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+  - first:
+      WebGL: WebGL
+    second:
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+  - first:
+      Windows Store Apps: WindowsStoreApps
+    second:
+      enabled: 0
+      settings:
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+  - first:
+      iPhone: iOS
+    second:
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Assets/Mirror/Tests/Editor.meta

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Assets/Mirror/Tests/Editor/Batching.meta

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+guid: 6d113040314b4578b93a6f140f064f09
+timeCreated: 1623240703

Assets/Mirror/Tests/Editor/Batching/BatcherTests.cs

@@ -0,0 +1,230 @@
+using System;
+using System.Linq;
+using NUnit.Framework;
+
+namespace Mirror.Tests.Batching
+{
+    public class BatcherTests
+    {
+        Batcher batcher;
+        const int Threshold = 8 + 4; // 8 bytes timestamp + 4 bytes message
+        NetworkWriter writer;
+
+        // timestamp and serialized timestamp for convenience
+        const double TimeStamp = Math.PI;
+
+        [SetUp]
+        public void SetUp()
+        {
+            batcher = new Batcher(Threshold);
+            writer = new NetworkWriter();
+        }
+
+        // helper function to create a batch prefixed by timestamp
+        public static byte[] ConcatTimestamp(double tickTimeStamp, byte[] data)
+        {
+            NetworkWriter writer = new NetworkWriter();
+            writer.WriteDouble(tickTimeStamp);
+            writer.WriteBytes(data, 0, data.Length);
+            return writer.ToArray();
+        }
+
+        [Test]
+        public void AddMessage()
+        {
+            byte[] message = {0x01, 0x02};
+            batcher.AddMessage(new ArraySegment<byte>(message));
+        }
+
+        [Test]
+        public void MakeNextBatch_OnlyAcceptsFreshWriter()
+        {
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x01}));
+
+            writer.WriteByte(0);
+            Assert.Throws<ArgumentException>(() => {
+                batcher.MakeNextBatch(writer, TimeStamp);
+            });
+        }
+
+        [Test]
+        public void MakeNextBatch_NoMessage()
+        {
+            // make batch with no message
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(false));
+        }
+
+        [Test]
+        public void MakeNextBatch_OneMessage()
+        {
+            // add message
+            byte[] message = {0x01, 0x02};
+            batcher.AddMessage(new ArraySegment<byte>(message));
+
+            // make batch
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, message)));
+        }
+
+        [Test]
+        public void MakeNextBatch_MultipleMessages_AlmostFullBatch()
+        {
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x01, 0x02}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x03}));
+
+            // make batch
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x01, 0x02, 0x03})));
+
+            // there should be no more batches to make
+            Assert.That(batcher.MakeNextBatch(writer, TimeStamp), Is.False);
+        }
+
+        [Test]
+        public void MakeNextBatch_MultipleMessages_ExactlyFullBatch()
+        {
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x01, 0x02}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x03, 0x04}));
+
+            // make batch
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x01, 0x02, 0x03, 0x04})));
+
+            // there should be no more batches to make
+            Assert.That(batcher.MakeNextBatch(writer, TimeStamp), Is.False);
+        }
+
+        [Test]
+        public void MakeNextBatch_MultipleMessages_MoreThanOneBatch()
+        {
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x01, 0x02}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x03, 0x04}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x05}));
+
+            // first batch
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x01, 0x02, 0x03, 0x04})));
+
+            // reset writer
+            writer.Position = 0;
+
+            // second batch
+            result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x05})));
+        }
+
+        [Test]
+        public void MakeNextBatch_MultipleMessages_Small_Giant_Small()
+        {
+            // small, too big to include in batch, small
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x01}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x02, 0x03, 0x04, 0x05}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x06, 0x07}));
+
+            // first batch
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x01})));
+
+            // reset writer
+            writer.Position = 0;
+
+            // second batch
+            result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x02, 0x03, 0x04, 0x05})));
+
+            // reset writer
+            writer.Position = 0;
+
+            // third batch
+            result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+
+            // check result: <<tickTimeStamp:8, message>>
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x06, 0x07})));
+        }
+
+        // messages > threshold should simply be single batches.
+        // those need to be supported too, for example:
+        //   kcp prefers MTU sized batches
+        //   but we still allow up to 144 KB max message size
+        [Test]
+        public void MakeNextBatch_LargerThanThreshold()
+        {
+            // make a larger than threshold message
+            byte[] large = new byte[Threshold + 1];
+            for (int i = 0; i < Threshold + 1; ++i)
+                large[i] = (byte)i;
+            batcher.AddMessage(new ArraySegment<byte>(large));
+
+            // result should be only the large message
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, large)));
+        }
+
+        // messages > threshold should simply be single batches.
+        // those need to be supported too, for example:
+        //   kcp prefers MTU sized batches
+        //   but we still allow up to 144 KB max message size
+        [Test]
+        public void MakeNextBatch_LargerThanThreshold_BetweenSmallerMessages()
+        {
+            // make a larger than threshold message
+            byte[] large = new byte[Threshold + 1];
+            for (int i = 0; i < Threshold + 1; ++i)
+                large[i] = (byte)i;
+
+            // add two small, one large, two small messages.
+            // to make sure everything around it is still batched,
+            // and the large one is a separate batch.
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x01}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x02}));
+            batcher.AddMessage(new ArraySegment<byte>(large));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x03}));
+            batcher.AddMessage(new ArraySegment<byte>(new byte[]{0x04}));
+
+            // first batch should be the two small messages
+            bool result = batcher.MakeNextBatch(writer, TimeStamp);
+            Assert.That(result, Is.EqualTo(true));
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp, new byte[]{0x01, 0x02})));
+
+            // reset writer
+            writer.Position = 0;
+
+            // second batch should be only the large message
+            result = batcher.MakeNextBatch(writer, TimeStamp + 1);
+            Assert.That(result, Is.EqualTo(true));
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp + 1, large)));
+
+            // reset writer
+            writer.Position = 0;
+
+            // third batch be the two small messages
+            result = batcher.MakeNextBatch(writer, TimeStamp + 2);
+            Assert.That(result, Is.EqualTo(true));
+            Assert.That(writer.ToArray().SequenceEqual(ConcatTimestamp(TimeStamp + 2, new byte[]{0x03, 0x04})));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/Batching/BatcherTests.cs.meta

@@ -0,0 +1,11 @@
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+  externalObjects: {}
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+  userData: 
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Assets/Mirror/Tests/Editor/Batching/UnbatcherTests.cs

@@ -0,0 +1,138 @@
+using System;
+using NUnit.Framework;
+
+namespace Mirror.Tests.Batching
+{
+    public class UnbatcherTests
+    {
+        Unbatcher unbatcher;
+        const double TimeStamp = Math.PI;
+
+        [SetUp]
+        public void SetUp()
+        {
+            unbatcher = new Unbatcher();
+        }
+
+        [Test]
+        public void GetNextMessage_NoBatches()
+        {
+            bool result = unbatcher.GetNextMessage(out _, out _);
+            Assert.That(result, Is.False);
+        }
+
+        // test for nimoyd bug, where calling getnextmessage after the previous
+        // call already returned false would cause an InvalidOperationException.
+        [Test]
+        public void GetNextMessage_True_False_False_InvalidOperationException()
+        {
+            // add batch
+            byte[] batch = BatcherTests.ConcatTimestamp(TimeStamp, new byte[2]);
+            unbatcher.AddBatch(new ArraySegment<byte>(batch));
+
+            // get next message, pretend we read the whole thing
+            bool result = unbatcher.GetNextMessage(out NetworkReader reader, out _);
+            Assert.That(result, Is.True);
+            reader.Position = reader.Length;
+
+            // shouldn't get another one
+            result = unbatcher.GetNextMessage(out reader, out _);
+            Assert.That(result, Is.False);
+
+            // calling it again was causing "InvalidOperationException: Queue empty"
+            result = unbatcher.GetNextMessage(out reader, out _);
+            Assert.That(result, Is.False);
+        }
+
+        [Test]
+        public void GetNextMessage_OneBatch()
+        {
+            // add one batch
+            byte[] batch = BatcherTests.ConcatTimestamp(TimeStamp, new byte[]{0x01, 0x02});
+            unbatcher.AddBatch(new ArraySegment<byte>(batch));
+
+            // get next message, read first byte
+            bool result = unbatcher.GetNextMessage(out NetworkReader reader, out double remoteTimeStamp);
+            Assert.That(result, Is.True);
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x01));
+            Assert.That(remoteTimeStamp, Is.EqualTo(TimeStamp));
+
+            // get next message, read last byte
+            result = unbatcher.GetNextMessage(out reader, out remoteTimeStamp);
+            Assert.That(result, Is.True);
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x02));
+            Assert.That(remoteTimeStamp, Is.EqualTo(TimeStamp));
+
+            // there should be no more messages
+            result = unbatcher.GetNextMessage(out _, out _);
+            Assert.That(result, Is.False);
+        }
+
+        [Test]
+        public void GetNextMessage_MultipleBatches()
+        {
+            // add first batch
+            byte[] firstBatch = BatcherTests.ConcatTimestamp(TimeStamp, new byte[]{0x01, 0x02});
+            unbatcher.AddBatch(new ArraySegment<byte>(firstBatch));
+
+            // add second batch
+            byte[] secondBatch = BatcherTests.ConcatTimestamp(TimeStamp + 1, new byte[]{0x03, 0x04});
+            unbatcher.AddBatch(new ArraySegment<byte>(secondBatch));
+
+            // get next message, read everything
+            bool result = unbatcher.GetNextMessage(out NetworkReader reader, out double remoteTimeStamp);
+            Assert.That(result, Is.True);
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x01));
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x02));
+            Assert.That(remoteTimeStamp, Is.EqualTo(TimeStamp));
+
+            // get next message, should point to next batch at Timestamp + 1
+            result = unbatcher.GetNextMessage(out reader, out remoteTimeStamp);
+            Assert.That(result, Is.True);
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x03));
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x04));
+            Assert.That(remoteTimeStamp, Is.EqualTo(TimeStamp + 1));
+
+            // there should be no more messages
+            result = unbatcher.GetNextMessage(out _, out _);
+            Assert.That(result, Is.False);
+        }
+
+        // make sure that retiring a batch, then adding a new batch works.
+        // previously there was a bug where the batch was retired,
+        // the reader still pointed to the old batch with pos=len,
+        // a new batch was added
+        // GetNextMessage() still returned false because reader still pointed to
+        // the old batch with pos=len.
+        [Test]
+        public void RetireBatchAndTryNewBatch()
+        {
+            // add first batch
+            byte[] firstBatch = BatcherTests.ConcatTimestamp(TimeStamp, new byte[]{0x01, 0x02});
+            unbatcher.AddBatch(new ArraySegment<byte>(firstBatch));
+
+            // read everything
+            bool result = unbatcher.GetNextMessage(out NetworkReader reader, out double remoteTimeStamp);
+            Assert.That(result, Is.True);
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x01));
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x02));
+            Assert.That(remoteTimeStamp, Is.EqualTo(TimeStamp));
+
+            // try to read again.
+            // reader will be at limit, which should retire the batch.
+            result = unbatcher.GetNextMessage(out _, out _);
+            Assert.That(result, Is.False);
+
+            // add new batch
+            byte[] secondBatch = BatcherTests.ConcatTimestamp(TimeStamp + 1, new byte[]{0x03, 0x04});
+            unbatcher.AddBatch(new ArraySegment<byte>(secondBatch));
+
+            // read everything
+            result = unbatcher.GetNextMessage(out reader, out remoteTimeStamp);
+            Assert.That(result, Is.True);
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x03));
+            Assert.That(reader.ReadByte(), Is.EqualTo(0x04));
+            Assert.That(remoteTimeStamp, Is.EqualTo(TimeStamp + 1));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/Batching/UnbatcherTests.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: ccc928bb22f5469886cef8c6132aa717
+timeCreated: 1623240730

Assets/Mirror/Tests/Editor/ClientRpcOverrideTest.cs

@@ -0,0 +1,134 @@
+using System;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests.RemoteAttrributeTest
+{
+    class VirtualClientRpc : NetworkBehaviour
+    {
+        public event Action<int> onVirtualSendInt;
+
+        [ClientRpc]
+        public virtual void RpcSendInt(int someInt) =>
+            onVirtualSendInt?.Invoke(someInt);
+    }
+
+    class VirtualNoOverrideClientRpc : VirtualClientRpc {}
+
+    class VirtualOverrideClientRpc : VirtualClientRpc
+    {
+        public event Action<int> onOverrideSendInt;
+
+        [ClientRpc]
+        public override void RpcSendInt(int someInt) =>
+            onOverrideSendInt?.Invoke(someInt);
+    }
+
+    class VirtualOverrideClientRpcWithBase : VirtualClientRpc
+    {
+        public event Action<int> onOverrideSendInt;
+
+        [ClientRpc]
+        public override void RpcSendInt(int someInt)
+        {
+            base.RpcSendInt(someInt);
+            onOverrideSendInt?.Invoke(someInt);
+        }
+    }
+
+    public class ClientRpcOverrideTest : RemoteTestBase
+    {
+        [Test]
+        public void VirtualRpcIsCalled()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualClientRpc hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.RpcSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void VirtualCommandWithNoOverrideIsCalled()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualNoOverrideClientRpc hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.RpcSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void OverrideVirtualRpcIsCalled()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualOverrideClientRpc hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            int overrideCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+            };
+            hostBehaviour.onOverrideSendInt += incomingInt =>
+            {
+                overrideCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.RpcSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(0));
+            Assert.That(overrideCallCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void OverrideVirtualWithBaseCallsBothVirtualAndBase()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualOverrideClientRpcWithBase hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            int overrideCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.onOverrideSendInt += incomingInt =>
+            {
+                overrideCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.RpcSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(1));
+            Assert.That(overrideCallCount, Is.EqualTo(1));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ClientRpcOverrideTest.cs.meta

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+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientRpcTest.cs

@@ -0,0 +1,155 @@
+using System;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests.RemoteAttrributeTest
+{
+    class ClientRpcBehaviour : NetworkBehaviour
+    {
+        public event Action<int> onSendInt;
+
+        [ClientRpc]
+        public void SendInt(int someInt) =>
+            onSendInt?.Invoke(someInt);
+    }
+
+    class ExcludeOwnerBehaviour : NetworkBehaviour
+    {
+        public event Action<int> onSendInt;
+
+        [ClientRpc(includeOwner = false)]
+        public void RpcSendInt(int someInt) =>
+            onSendInt?.Invoke(someInt);
+    }
+
+    class AbstractNetworkBehaviourClientRpcBehaviour : NetworkBehaviour
+    {
+        public abstract class MockMonsterBase : NetworkBehaviour {}
+        public class MockZombie : MockMonsterBase {}
+        public class MockWolf : MockMonsterBase {}
+
+        public event Action<MockMonsterBase> onSendMonsterBase;
+
+        [ClientRpc]
+        public void RpcSendMonster(MockMonsterBase someMonster) =>
+            onSendMonsterBase?.Invoke(someMonster);
+    }
+
+    class RpcOverloads : NetworkBehaviour
+    {
+        public int firstCalled = 0;
+        public int secondCalled = 0;
+
+        [ClientRpc]
+        public void RpcTest(int _) => ++firstCalled;
+
+        [ClientRpc]
+        public void RpcTest(string _) => ++secondCalled;
+    }
+
+    public class ClientRpcTest : RemoteTestBase
+    {
+        [Test]
+        public void RpcIsCalled()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out ClientRpcBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int called = 0;
+            hostBehaviour.onSendInt += incomingInt =>
+            {
+                called++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.SendInt(someInt);
+            ProcessMessages();
+            Assert.That(called, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void RpcIsCalledForNotOwner()
+        {
+            // spawn without owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out ExcludeOwnerBehaviour hostBehaviour);
+
+            const int someInt = 20;
+
+            int called = 0;
+            hostBehaviour.onSendInt += incomingInt =>
+            {
+                called++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.RpcSendInt(someInt);
+            ProcessMessages();
+            Assert.That(called, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void RpcNotCalledForOwner()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out ExcludeOwnerBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int called = 0;
+            hostBehaviour.onSendInt += incomingInt =>
+            {
+                called++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.RpcSendInt(someInt);
+            ProcessMessages();
+            Assert.That(called, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void RpcIsCalledWithAbstractNetworkBehaviourParameter()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out AbstractNetworkBehaviourClientRpcBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            // spawn clientrpc parameter targets
+            CreateNetworkedAndSpawn(out _, out _, out AbstractNetworkBehaviourClientRpcBehaviour.MockWolf wolf, NetworkServer.localConnection);
+            CreateNetworkedAndSpawn(out _, out _, out AbstractNetworkBehaviourClientRpcBehaviour.MockZombie zombie, NetworkServer.localConnection);
+
+            AbstractNetworkBehaviourClientRpcBehaviour.MockMonsterBase currentMonster = null;
+
+            int called = 0;
+            hostBehaviour.onSendMonsterBase += incomingMonster =>
+            {
+                called++;
+                Assert.That(incomingMonster, Is.EqualTo(currentMonster));
+            };
+
+            currentMonster = wolf;
+            hostBehaviour.RpcSendMonster(currentMonster);
+            ProcessMessages();
+            Assert.That(called, Is.EqualTo(1));
+
+            currentMonster = zombie;
+            hostBehaviour.RpcSendMonster(currentMonster);
+            ProcessMessages();
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        // RemoteCalls uses md.FullName which gives us the full command/rpc name
+        // like "System.Void Mirror.Tests.RemoteAttrributeTest.AuthorityBehaviour::SendInt(System.Int32)"
+        // which means overloads with same name but different types should work.
+        [Test]
+        public void RpcOverload()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out RpcOverloads hostBehaviour, NetworkServer.localConnection);
+
+            hostBehaviour.RpcTest(42);
+            hostBehaviour.RpcTest("A");
+            ProcessMessages();
+            Assert.That(hostBehaviour.firstCalled, Is.EqualTo(1));
+            Assert.That(hostBehaviour.secondCalled, Is.EqualTo(1));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ClientRpcTest.cs.meta

@@ -0,0 +1,11 @@
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+guid: 2928376e56382b646975dd00b68c2287
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientSceneTests_ClearSpawners.cs

@@ -0,0 +1,58 @@
+using System;
+using NUnit.Framework;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class ClientSceneTests_ClearSpawners : ClientSceneTestsBase
+    {
+        [Test]
+        public void RemovesAllPrefabsFromDictionary()
+        {
+            NetworkClient.prefabs.Add(Guid.NewGuid(), null);
+            NetworkClient.prefabs.Add(Guid.NewGuid(), null);
+
+            NetworkClient.ClearSpawners();
+            Assert.IsEmpty(NetworkClient.prefabs);
+        }
+
+        [Test]
+        public void RemovesAllSpawnHandlersFromDictionary()
+        {
+            NetworkClient.spawnHandlers.Add(Guid.NewGuid(), null);
+            NetworkClient.spawnHandlers.Add(Guid.NewGuid(), null);
+
+            NetworkClient.ClearSpawners();
+            Assert.IsEmpty(NetworkClient.spawnHandlers);
+        }
+
+        [Test]
+        public void RemovesAllUnspawnHandlersFromDictionary()
+        {
+            NetworkClient.unspawnHandlers.Add(Guid.NewGuid(), null);
+            NetworkClient.unspawnHandlers.Add(Guid.NewGuid(), null);
+
+            NetworkClient.ClearSpawners();
+
+            Assert.IsEmpty(NetworkClient.unspawnHandlers);
+        }
+
+        [Test]
+        public void ClearsAllDictionary()
+        {
+            NetworkClient.prefabs.Add(Guid.NewGuid(), null);
+            NetworkClient.prefabs.Add(Guid.NewGuid(), null);
+
+            NetworkClient.spawnHandlers.Add(Guid.NewGuid(), null);
+            NetworkClient.spawnHandlers.Add(Guid.NewGuid(), null);
+
+            NetworkClient.unspawnHandlers.Add(Guid.NewGuid(), null);
+            NetworkClient.unspawnHandlers.Add(Guid.NewGuid(), null);
+
+            NetworkClient.ClearSpawners();
+
+            Assert.IsEmpty(NetworkClient.prefabs);
+            Assert.IsEmpty(NetworkClient.spawnHandlers);
+            Assert.IsEmpty(NetworkClient.unspawnHandlers);
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_ClearSpawners.cs.meta

@@ -0,0 +1,11 @@
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+guid: ad2fe5633a9652045a5f7eb2643b6956
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+  serializedVersion: 2
+  defaultReferences: []
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+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientSceneTests_GetPrefab.cs

@@ -0,0 +1,62 @@
+using System;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class ClientSceneTests_GetPrefab : ClientSceneTestsBase
+    {
+        [Test]
+        public void ReturnsFalseForEmptyGuid()
+        {
+            bool result = NetworkClient.GetPrefab(new Guid(), out GameObject prefab);
+
+            Assert.IsFalse(result);
+            Assert.IsNull(prefab);
+        }
+
+        [Test]
+        public void ReturnsFalseForPrefabNotFound()
+        {
+            Guid guid = Guid.NewGuid();
+            bool result = NetworkClient.GetPrefab(guid, out GameObject prefab);
+
+            Assert.IsFalse(result);
+            Assert.IsNull(prefab);
+        }
+
+        [Test]
+        public void ReturnsFalseForPrefabIsNull()
+        {
+            Guid guid = Guid.NewGuid();
+            NetworkClient.prefabs.Add(guid, null);
+            bool result = NetworkClient.GetPrefab(guid, out GameObject prefab);
+
+            Assert.IsFalse(result);
+            Assert.IsNull(prefab);
+        }
+
+        [Test]
+        public void ReturnsTrueWhenPrefabIsFound()
+        {
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+            bool result = NetworkClient.GetPrefab(validPrefabGuid, out GameObject prefab);
+
+            Assert.IsTrue(result);
+            Assert.NotNull(prefab);
+        }
+
+        [Test]
+        public void HasOutPrefabWithCorrectGuid()
+        {
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+            NetworkClient.GetPrefab(validPrefabGuid, out GameObject prefab);
+
+
+            Assert.NotNull(prefab);
+
+            NetworkIdentity networkID = prefab.GetComponent<NetworkIdentity>();
+            Assert.AreEqual(networkID.assetId, validPrefabGuid);
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_GetPrefab.cs.meta

@@ -0,0 +1,11 @@
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+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientSceneTests_OnSpawn.cs

@@ -0,0 +1,736 @@
+using System;
+using System.Collections.Generic;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class PayloadTestBehaviour : NetworkBehaviour
+    {
+        public int value;
+        public Vector3 direction;
+
+        public event Action OnDeserializeCalled;
+        public event Action OnSerializeCalled;
+
+        public override bool OnSerialize(NetworkWriter writer, bool initialState)
+        {
+            base.OnSerialize(writer, initialState);
+
+            writer.WriteInt(value);
+            writer.WriteVector3(direction);
+
+            OnSerializeCalled?.Invoke();
+
+            return true;
+        }
+        public override void OnDeserialize(NetworkReader reader, bool initialState)
+        {
+            base.OnDeserialize(reader, initialState);
+
+            value = reader.ReadInt();
+            direction = reader.ReadVector3();
+
+            OnDeserializeCalled?.Invoke();
+        }
+    }
+
+    public class BehaviourWithEvents : NetworkBehaviour
+    {
+        public event Action OnStartAuthorityCalled;
+        public event Action OnStartClientCalled;
+        public event Action OnStartLocalPlayerCalled;
+
+        public override void OnStartAuthority()
+        {
+            OnStartAuthorityCalled?.Invoke();
+        }
+        public override void OnStartClient()
+        {
+            OnStartClientCalled?.Invoke();
+        }
+        public override void OnStartLocalPlayer()
+        {
+            OnStartLocalPlayerCalled?.Invoke();
+        }
+    }
+
+    public class ClientSceneTests_OnSpawn : ClientSceneTestsBase
+    {
+        Dictionary<uint, NetworkIdentity> spawned => NetworkClient.spawned;
+
+        [TearDown]
+        public override void TearDown()
+        {
+            spawned.Clear();
+            base.TearDown();
+        }
+
+        [Test]
+        public void FindOrSpawnObject_FindExistingObject()
+        {
+            CreateNetworked(out _, out NetworkIdentity existing);
+            const uint netId = 1000;
+            existing.netId = netId;
+            spawned.Add(netId, existing);
+
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId
+            };
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity found);
+
+            Assert.IsTrue(success);
+            Assert.That(found, Is.EqualTo(existing));
+        }
+
+        [Test]
+        public void FindOrSpawnObject_ErrorWhenNoExistingAndAssetIdAndSceneIdAreBothEmpty()
+        {
+            const uint netId = 1001;
+            SpawnMessage msg = new SpawnMessage
+            {
+                assetId = new Guid(),
+                sceneId = 0,
+                netId = netId
+            };
+
+            LogAssert.Expect(LogType.Error, $"OnSpawn message with netId '{netId}' has no AssetId or sceneId");
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsFalse(success);
+            Assert.IsNull(networkIdentity);
+        }
+
+        [Test]
+        public void FindOrSpawnObject_SpawnsFromPrefabDictionary()
+        {
+            const uint netId = 1002;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                assetId = validPrefabGuid
+
+            };
+
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsTrue(success);
+            Assert.IsNotNull(networkIdentity);
+            Assert.That(networkIdentity.name, Is.EqualTo($"{validPrefab.name}(Clone)"));
+
+            // cleanup
+            GameObject.DestroyImmediate(networkIdentity.gameObject);
+        }
+
+        [Test]
+        public void FindOrSpawnObject_ErrorWhenPrefabInNullInDictionary()
+        {
+            const uint netId = 1002;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                assetId = validPrefabGuid
+            };
+
+            // could happen if the prefab is destroyed or unloaded
+            NetworkClient.prefabs.Add(validPrefabGuid, null);
+
+            LogAssert.Expect(LogType.Error, $"Failed to spawn server object, did you forget to add it to the NetworkManager? assetId={msg.assetId} netId={msg.netId}");
+            LogAssert.Expect(LogType.Error, $"Could not spawn assetId={msg.assetId} scene={msg.sceneId:X} netId={msg.netId}");
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+
+            Assert.IsFalse(success);
+            Assert.IsNull(networkIdentity);
+        }
+
+        [Test]
+        public void FindOrSpawnObject_SpawnsFromPrefabIfBothPrefabAndHandlerExists()
+        {
+            const uint netId = 1003;
+            int handlerCalled = 0;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                assetId = validPrefabGuid
+            };
+
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+            NetworkClient.spawnHandlers.Add(validPrefabGuid, x =>
+            {
+                handlerCalled++;
+                CreateNetworked(out GameObject go, out NetworkIdentity _);
+                return go;
+            });
+
+
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsTrue(success);
+            Assert.IsNotNull(networkIdentity);
+            Assert.That(networkIdentity.name, Is.EqualTo($"{validPrefab.name}(Clone)"));
+            Assert.That(handlerCalled, Is.EqualTo(0), "Handler should not have been called");
+        }
+
+        [Test]
+        public void FindOrSpawnObject_SpawnHandlerCalledFromDictionary()
+        {
+            const uint netId = 1003;
+            int handlerCalled = 0;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                assetId = validPrefabGuid
+            };
+
+            GameObject createdInhandler = null;
+
+            NetworkClient.spawnHandlers.Add(validPrefabGuid, x =>
+            {
+                handlerCalled++;
+                Assert.That(x, Is.EqualTo(msg));
+                CreateNetworked(out createdInhandler, out NetworkIdentity _);
+                return createdInhandler;
+            });
+
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsTrue(success);
+            Assert.IsNotNull(networkIdentity);
+            Assert.That(handlerCalled, Is.EqualTo(1));
+            Assert.That(networkIdentity.gameObject, Is.EqualTo(createdInhandler), "Object returned should be the same object created by the spawn handler");
+        }
+
+        [Test]
+        public void FindOrSpawnObject_ErrorWhenSpawnHanlderReturnsNull()
+        {
+            const uint netId = 1003;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                assetId = validPrefabGuid
+            };
+
+            NetworkClient.spawnHandlers.Add(validPrefabGuid, (x) => null);
+
+            LogAssert.Expect(LogType.Error, $"Spawn Handler returned null, Handler assetId '{msg.assetId}'");
+            LogAssert.Expect(LogType.Error, $"Could not spawn assetId={msg.assetId} scene={msg.sceneId:X} netId={msg.netId}");
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsFalse(success);
+            Assert.IsNull(networkIdentity);
+        }
+        [Test]
+        public void FindOrSpawnObject_ErrorWhenSpawnHanlderReturnsWithoutNetworkIdentity()
+        {
+            const uint netId = 1003;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                assetId = validPrefabGuid
+            };
+
+            NetworkClient.spawnHandlers.Add(validPrefabGuid, (x) =>
+            {
+                CreateGameObject(out GameObject go);
+                return go;
+            });
+
+            LogAssert.Expect(LogType.Error, $"Object Spawned by handler did not have a NetworkIdentity, Handler assetId '{validPrefabGuid}'");
+            LogAssert.Expect(LogType.Error, $"Could not spawn assetId={msg.assetId} scene={msg.sceneId:X} netId={msg.netId}");
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsFalse(success);
+            Assert.IsNull(networkIdentity);
+        }
+
+        NetworkIdentity CreateSceneObject(ulong sceneId)
+        {
+            CreateNetworked(out _, out NetworkIdentity identity);
+            // set sceneId to zero as it is set in onvalidate (does not set id at runtime)
+            identity.sceneId = sceneId;
+            NetworkClient.spawnableObjects.Add(sceneId, identity);
+            return identity;
+        }
+
+        [Test]
+        public void FindOrSpawnObject_UsesSceneIdToSpawnFromSpawnableObjectsDictionary()
+        {
+            const uint netId = 1003;
+            const int sceneId = 100020;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                sceneId = sceneId
+            };
+
+            NetworkIdentity sceneObject = CreateSceneObject(sceneId);
+
+
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsTrue(success);
+            Assert.IsNotNull(networkIdentity);
+            Assert.That(networkIdentity, Is.EqualTo(sceneObject));
+        }
+
+        [Test]
+        public void FindOrSpawnObject_SpawnsUsingSceneIdInsteadOfAssetId()
+        {
+            const uint netId = 1003;
+            const int sceneId = 100020;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                sceneId = sceneId,
+                assetId = validPrefabGuid
+            };
+
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+            NetworkIdentity sceneObject = CreateSceneObject(sceneId);
+
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsTrue(success);
+            Assert.IsNotNull(networkIdentity);
+            Assert.That(networkIdentity, Is.EqualTo(sceneObject));
+        }
+
+        [Test]
+        public void FindOrSpawnObject_ErrorWhenSceneIdIsNotInSpawnableObjectsDictionary()
+        {
+            const uint netId = 1004;
+            const int sceneId = 100021;
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                sceneId = sceneId,
+            };
+
+            LogAssert.Expect(LogType.Error, $"Spawn scene object not found for {msg.sceneId:X}. Make sure that client and server use exactly the same project. This only happens if the hierarchy gets out of sync.");
+            LogAssert.Expect(LogType.Error, $"Could not spawn assetId={msg.assetId} scene={msg.sceneId:X} netId={msg.netId}");
+            bool success = NetworkClient.FindOrSpawnObject(msg, out NetworkIdentity networkIdentity);
+
+            Assert.IsFalse(success);
+            Assert.IsNull(networkIdentity);
+        }
+
+
+        [Test]
+        public void ApplyPayload_AppliesTransform()
+        {
+            const uint netId = 1000;
+
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            Vector3 position = new Vector3(10, 0, 20);
+            Quaternion rotation = Quaternion.Euler(0, 45, 0);
+            Vector3 scale = new Vector3(1.5f, 1.5f, 1.5f);
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = false,
+                isOwner = false,
+                sceneId = 0,
+                assetId = Guid.Empty,
+                // use local values for VR support
+                position = position,
+                rotation = rotation,
+                scale = scale,
+
+                payload = default,
+            };
+
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.That(identity.transform.position, Is.EqualTo(position));
+            // use angle because of floating point numbers
+            // only need to check if rotations are approximately equal
+            Assert.That(Quaternion.Angle(identity.transform.rotation, rotation), Is.LessThan(0.0001f));
+            Assert.That(identity.transform.localScale, Is.EqualTo(scale));
+        }
+
+        [Test]
+        public void ApplyPayload_AppliesLocalValuesToTransform()
+        {
+            const uint netId = 1000;
+            CreateGameObject(out GameObject parent);
+            parent.transform.position = new Vector3(100, 20, 0);
+            parent.transform.rotation = Quaternion.LookRotation(Vector3.left);
+            parent.transform.localScale = Vector3.one * 2;
+
+            CreateNetworked(out GameObject go, out NetworkIdentity identity);
+            go.transform.parent = parent.transform;
+
+            Vector3 position = new Vector3(10, 0, 20);
+            Quaternion rotation = Quaternion.Euler(0, 45, 0);
+            Vector3 scale = new Vector3(1.5f, 1.5f, 1.5f);
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = false,
+                isOwner = false,
+                sceneId = 0,
+                assetId = Guid.Empty,
+                // use local values for VR support
+                position = position,
+                rotation = rotation,
+                scale = scale,
+
+                payload = default,
+            };
+
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.That(identity.transform.localPosition, Is.EqualTo(position));
+            // use angle because of floating point numbers
+            // only need to check if rotations are approximately equal
+            Assert.That(Quaternion.Angle(identity.transform.localRotation, rotation), Is.LessThan(0.0001f));
+            Assert.That(identity.transform.localScale, Is.EqualTo(scale));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void ApplyPayload_AppliesAuthority(bool isOwner)
+        {
+            const uint netId = 1000;
+
+            CreateNetworked(out _, out NetworkIdentity identity);
+
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = false,
+                isOwner = isOwner,
+                sceneId = 0,
+                assetId = Guid.Empty,
+                // use local values for VR support
+                position = Vector3.zero,
+                rotation = Quaternion.identity,
+                scale = Vector3.one,
+
+                payload = default
+            };
+
+            // set to opposite to make sure it is changed
+            identity.hasAuthority = !isOwner;
+
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.That(identity.hasAuthority, Is.EqualTo(isOwner));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void ApplyPayload_EnablesObject(bool startActive)
+        {
+            const uint netId = 1000;
+
+            CreateNetworked(out GameObject go, out NetworkIdentity identity);
+            go.SetActive(startActive);
+
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = false,
+                isOwner = false,
+                sceneId = 0,
+                assetId = Guid.Empty,
+                // use local values for VR support
+                position = Vector3.zero,
+                rotation = Quaternion.identity,
+                scale = Vector3.one,
+
+                payload = default,
+            };
+
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.IsTrue(identity.gameObject.activeSelf);
+        }
+
+        [Test]
+        public void ApplyPayload_SetsAssetId()
+        {
+            const uint netId = 1000;
+
+            CreateNetworked(out _, out NetworkIdentity identity);
+
+            Guid guid = Guid.NewGuid();
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = false,
+                isOwner = false,
+                sceneId = 0,
+                assetId = guid,
+                // use local values for VR support
+                position = Vector3.zero,
+                rotation = Quaternion.identity,
+                scale = Vector3.one,
+
+                payload = default
+            };
+
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.IsTrue(identity.gameObject.activeSelf);
+
+            Assert.That(identity.assetId, Is.EqualTo(guid));
+        }
+
+        [Test]
+        public void ApplyPayload_DoesNotSetAssetIdToEmpty()
+        {
+            const uint netId = 1000;
+
+            CreateNetworked(out _, out NetworkIdentity identity);
+            Guid guid = Guid.NewGuid();
+            identity.assetId = guid;
+
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = false,
+                isOwner = false,
+                sceneId = 0,
+                assetId = Guid.Empty,
+                // use local values for VR support
+                position = Vector3.zero,
+                rotation = Quaternion.identity,
+                scale = Vector3.one,
+
+                payload = default
+            };
+
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.That(identity.assetId, Is.EqualTo(guid), "AssetId should not have changed");
+        }
+
+        [Test]
+        public void ApplyPayload_SendsDataToNetworkBehaviourDeserialize()
+        {
+            const int value = 12;
+            Vector3 direction = new Vector3(0, 1, 1);
+
+            const uint netId = 1000;
+
+            // server object
+            CreateNetworked(out _, out NetworkIdentity serverIdentity, out PayloadTestBehaviour serverPayloadBehaviour);
+
+            // client object
+            CreateNetworked(out _, out NetworkIdentity clientIdentity, out PayloadTestBehaviour clientPayloadBehaviour);
+
+            int onSerializeCalled = 0;
+            serverPayloadBehaviour.OnSerializeCalled += () => { onSerializeCalled++; };
+
+            int onDeserializeCalled = 0;
+            clientPayloadBehaviour.OnDeserializeCalled += () => { onDeserializeCalled++; };
+
+            serverPayloadBehaviour.value = value;
+            serverPayloadBehaviour.direction = direction;
+
+            NetworkWriter ownerWriter = new NetworkWriter();
+            NetworkWriter observersWriter = new NetworkWriter();
+            serverIdentity.OnSerializeAllSafely(true, ownerWriter, observersWriter);
+
+            // check that Serialize was called
+            Assert.That(onSerializeCalled, Is.EqualTo(1));
+
+            // create spawn message
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                payload = ownerWriter.ToArraySegment(),
+            };
+
+            // check values start default
+            Assert.That(onDeserializeCalled, Is.EqualTo(0));
+            Assert.That(clientPayloadBehaviour.value, Is.EqualTo(0));
+            Assert.That(clientPayloadBehaviour.direction, Is.EqualTo(Vector3.zero));
+
+            NetworkClient.ApplySpawnPayload(clientIdentity, msg);
+
+            // check values have been set by payload
+            Assert.That(onDeserializeCalled, Is.EqualTo(1));
+            Assert.That(clientPayloadBehaviour.value, Is.EqualTo(value));
+            Assert.That(clientPayloadBehaviour.direction, Is.EqualTo(direction));
+        }
+
+        [Test]
+        public void ApplyPayload_LocalPlayerAddsIdentityToConnection()
+        {
+            Debug.Assert(NetworkClient.localPlayer == null, "LocalPlayer should be null before this test");
+            const uint netId = 1000;
+
+            CreateNetworked(out _, out NetworkIdentity identity);
+
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = true,
+                isOwner = true,
+                sceneId = 0,
+                assetId = Guid.Empty,
+                // use local values for VR support
+                position = Vector3.zero,
+                rotation = Quaternion.identity,
+                scale = Vector3.one,
+
+                payload = default,
+            };
+
+            NetworkClient.connection = new FakeNetworkConnection();
+            NetworkClient.ready = true;
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.That(NetworkClient.localPlayer, Is.EqualTo(identity));
+            Assert.That(NetworkClient.connection.identity, Is.EqualTo(identity));
+        }
+
+        [Test]
+        public void ApplyPayload_LocalPlayerWarningWhenNoReadyConnection()
+        {
+            Debug.Assert(NetworkClient.localPlayer == null, "LocalPlayer should be null before this test");
+            const uint netId = 1000;
+
+            CreateNetworked(out _, out NetworkIdentity identity);
+
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = true,
+                isOwner = true,
+                sceneId = 0,
+                assetId = Guid.Empty,
+                // use local values for VR support
+                position = Vector3.zero,
+                rotation = Quaternion.identity,
+                scale = Vector3.one,
+
+                payload = default,
+            };
+
+
+            LogAssert.Expect(LogType.Warning, "No ready connection found for setting player controller during InternalAddPlayer");
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            Assert.That(NetworkClient.localPlayer, Is.EqualTo(identity));
+        }
+
+        [Flags]
+        public enum SpawnFinishedState
+        {
+            isSpawnFinished = 1,
+            hasAuthority = 2,
+            isLocalPlayer = 4
+        }
+        [Test]
+        [TestCase(0)]
+        [TestCase(1)]
+        [TestCase(2)]
+        [TestCase(3)]
+        [TestCase(4)]
+        [TestCase(5)]
+        [TestCase(6)]
+        [TestCase(7)]
+        public void ApplyPayload_isSpawnFinished(SpawnFinishedState flag)
+        {
+            bool isSpawnFinished = flag.HasFlag(SpawnFinishedState.isSpawnFinished);
+            bool hasAuthority = flag.HasFlag(SpawnFinishedState.hasAuthority);
+            bool isLocalPlayer = flag.HasFlag(SpawnFinishedState.isLocalPlayer);
+
+            if (isSpawnFinished)
+            {
+                NetworkClient.OnObjectSpawnFinished(new ObjectSpawnFinishedMessage());
+            }
+
+            const uint netId = 1000;
+            CreateNetworked(out _, out NetworkIdentity identity, out BehaviourWithEvents events);
+
+            int onStartAuthorityCalled = 0;
+            int onStartClientCalled = 0;
+            int onStartLocalPlayerCalled = 0;
+            events.OnStartAuthorityCalled += () => { onStartAuthorityCalled++; };
+            events.OnStartClientCalled += () => { onStartClientCalled++; };
+            events.OnStartLocalPlayerCalled += () => { onStartLocalPlayerCalled++; };
+
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                isLocalPlayer = isLocalPlayer,
+                isOwner = hasAuthority,
+            };
+
+            NetworkClient.ApplySpawnPayload(identity, msg);
+
+            if (isSpawnFinished)
+            {
+                Assert.That(onStartClientCalled, Is.EqualTo(1));
+                Assert.That(onStartAuthorityCalled, Is.EqualTo(hasAuthority ? 1 : 0));
+                Assert.That(onStartLocalPlayerCalled, Is.EqualTo(isLocalPlayer ? 1 : 0));
+            }
+            else
+            {
+                Assert.That(onStartAuthorityCalled, Is.Zero);
+                Assert.That(onStartClientCalled, Is.Zero);
+                Assert.That(onStartLocalPlayerCalled, Is.Zero);
+            }
+        }
+
+        [Test]
+        public void OnSpawn_SpawnsAndAppliesPayload()
+        {
+            const int netId = 1;
+            Debug.Assert(spawned.Count == 0, "There should be no spawned objects before test");
+
+            Vector3 position = new Vector3(30, 20, 10);
+            Quaternion rotation = Quaternion.Euler(0, 0, 90);
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+                assetId = validPrefabGuid,
+                position = position,
+                rotation = rotation
+            };
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+
+            NetworkClient.OnSpawn(msg);
+
+            Assert.That(spawned.Count, Is.EqualTo(1));
+            Assert.IsTrue(spawned.ContainsKey(netId));
+
+            NetworkIdentity identity = spawned[netId];
+            Assert.IsNotNull(identity);
+            Assert.That(identity.name, Is.EqualTo($"{validPrefab.name}(Clone)"));
+            Assert.That(identity.transform.position, Is.EqualTo(position));
+            // use angle because of floating point numbers
+            // only need to check if rotations are approximately equal
+            Assert.That(Quaternion.Angle(identity.transform.rotation, rotation), Is.LessThan(0.0001f));
+        }
+
+        [Test]
+        public void OnSpawn_GiveNoExtraErrorsWhenPrefabIsntSpawned()
+        {
+            const int netId = 20033;
+            Debug.Assert(spawned.Count == 0, "There should be no spawned objects before test");
+            SpawnMessage msg = new SpawnMessage
+            {
+                netId = netId,
+            };
+
+            // Check for log that FindOrSpawnObject gives, and make sure there are no other error logs
+            LogAssert.Expect(LogType.Error, $"OnSpawn message with netId '{netId}' has no AssetId or sceneId");
+            NetworkClient.OnSpawn(msg);
+
+            Assert.That(spawned, Is.Empty);
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_OnSpawn.cs.meta

@@ -0,0 +1,11 @@
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+guid: b85d949dccc6ab4498da187264323dcc
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Assets/Mirror/Tests/Editor/ClientSceneTests_PrepareToSpawnSceneObjects.cs

@@ -0,0 +1,104 @@
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class ClientSceneTests_PrepareToSpawnSceneObjects : ClientSceneTestsBase
+    {
+        NetworkIdentity CreateSceneObject(ulong sceneId)
+        {
+            CreateNetworked(out GameObject gameObject, out NetworkIdentity identity);
+            gameObject.name = "Runtime GameObject";
+            // set sceneId to zero as it is set in onvalidate (does not set id at runtime)
+            identity.sceneId = sceneId;
+            return identity;
+        }
+
+        [Test]
+        public void AddsAllInactiveIdentitiesInSceneWithSceneIdToDictionary()
+        {
+            NetworkIdentity obj1 = CreateSceneObject(10);
+            NetworkIdentity obj2 = CreateSceneObject(11);
+
+            obj1.gameObject.SetActive(false);
+            obj2.gameObject.SetActive(false);
+
+            NetworkClient.PrepareToSpawnSceneObjects();
+
+            Assert.That(NetworkClient.spawnableObjects, Has.Count.EqualTo(2));
+
+            Assert.IsTrue(NetworkClient.spawnableObjects.ContainsValue(obj1));
+            Assert.IsTrue(NetworkClient.spawnableObjects.ContainsValue(obj2));
+        }
+
+        [Test]
+        public void DoesNotAddActiveObjectsToDictionary()
+        {
+            NetworkIdentity active = CreateSceneObject(30);
+            NetworkIdentity inactive = CreateSceneObject(32);
+
+            active.gameObject.SetActive(true);
+            inactive.gameObject.SetActive(false);
+
+            NetworkClient.PrepareToSpawnSceneObjects();
+
+            Assert.That(NetworkClient.spawnableObjects, Has.Count.EqualTo(1));
+            Assert.IsTrue(NetworkClient.spawnableObjects.ContainsValue(inactive));
+            Assert.IsFalse(NetworkClient.spawnableObjects.ContainsValue(active));
+        }
+
+        [Test]
+        public void DoesNotAddObjectsWithNoSceneId()
+        {
+            NetworkIdentity noId = CreateSceneObject(0);
+            NetworkIdentity hasId = CreateSceneObject(40);
+
+            noId.gameObject.SetActive(false);
+            hasId.gameObject.SetActive(false);
+
+            NetworkClient.PrepareToSpawnSceneObjects();
+
+            Assert.IsTrue(NetworkClient.spawnableObjects.ContainsValue(hasId));
+            Assert.IsFalse(NetworkClient.spawnableObjects.ContainsValue(noId));
+        }
+
+        [Test]
+        public void AddsIdentitiesToDictionaryUsingSceneId()
+        {
+            NetworkIdentity obj1 = CreateSceneObject(20);
+            NetworkIdentity obj2 = CreateSceneObject(21);
+            obj1.gameObject.SetActive(false);
+            obj2.gameObject.SetActive(false);
+
+            NetworkClient.PrepareToSpawnSceneObjects();
+
+            Assert.IsTrue(NetworkClient.spawnableObjects.ContainsKey(20));
+            Assert.That(NetworkClient.spawnableObjects[20], Is.EqualTo(obj1));
+
+            Assert.IsTrue(NetworkClient.spawnableObjects.ContainsKey(21));
+            Assert.That(NetworkClient.spawnableObjects[21], Is.EqualTo(obj2));
+        }
+
+        [Test]
+        public void ClearsExistingItemsFromDictionary()
+        {
+            // destroyed objects from old scene
+            NetworkClient.spawnableObjects.Add(60, null);
+            NetworkClient.spawnableObjects.Add(62, null);
+
+            // active object
+            NetworkIdentity obj1 = CreateSceneObject(61);
+            NetworkClient.spawnableObjects.Add(61, obj1);
+
+            // new disabled object
+            NetworkIdentity obj2 = CreateSceneObject(63);
+            obj2.gameObject.SetActive(false);
+
+            NetworkClient.PrepareToSpawnSceneObjects();
+
+            Assert.That(NetworkClient.spawnableObjects, Has.Count.EqualTo(1));
+            Assert.IsFalse(NetworkClient.spawnableObjects.ContainsValue(null));
+            Assert.IsTrue(NetworkClient.spawnableObjects.ContainsValue(obj2));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_PrepareToSpawnSceneObjects.cs.meta

@@ -0,0 +1,11 @@
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientSceneTests_RegisterPrefab.cs

@@ -0,0 +1,300 @@
+using System;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class ClientSceneTests_RegisterPrefab : ClientSceneTests_RegisterPrefabBase
+    {
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab)]
+        public void Prefab_AddsPrefabToDictionary(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+
+            CallRegisterPrefab(validPrefab, overload);
+
+            Assert.IsTrue(NetworkClient.prefabs.ContainsKey(guid));
+            Assert.AreEqual(NetworkClient.prefabs[guid], validPrefab);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_NewAssetId)]
+        public void PrefabNewGuid_ErrorDoesNotChangePrefabsAssetId(RegisterPrefabOverload overload)
+        {
+            Guid guid = anotherGuid;
+
+            LogAssert.Expect(LogType.Error, $"Could not register '{validPrefab.name}' to {guid} because it already had an AssetId, Existing assetId {validPrefabGuid}");
+            CallRegisterPrefab(validPrefab, overload);
+
+            Assert.IsFalse(NetworkClient.prefabs.ContainsKey(guid));
+
+            NetworkIdentity netId = validPrefab.GetComponent<NetworkIdentity>();
+
+            Assert.AreEqual(netId.assetId, validPrefabGuid);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId)]
+        public void HandlerNewGuid_ErrorDoesNotChangePrefabsAssetId(RegisterPrefabOverload overload)
+        {
+            Guid guid = anotherGuid;
+
+            LogAssert.Expect(LogType.Error, $"Could not register Handler for '{validPrefab.name}' to {guid} because it already had an AssetId, Existing assetId {validPrefabGuid}");
+            CallRegisterPrefab(validPrefab, overload);
+
+            Assert.IsFalse(NetworkClient.spawnHandlers.ContainsKey(guid));
+            Assert.IsFalse(NetworkClient.unspawnHandlers.ContainsKey(guid));
+
+            NetworkIdentity netId = validPrefab.GetComponent<NetworkIdentity>();
+
+            Assert.AreEqual(netId.assetId, validPrefabGuid);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_NewAssetId)]
+        public void PrefabNewGuid_NoErrorWhenNewAssetIdIsSameAsCurrentPrefab(RegisterPrefabOverload overload)
+        {
+            Guid guid = validPrefabGuid;
+
+            CallRegisterPrefab(validPrefab, overload, guid);
+
+            Assert.IsTrue(NetworkClient.prefabs.ContainsKey(guid));
+
+            NetworkIdentity netId = validPrefab.GetComponent<NetworkIdentity>();
+
+            Assert.AreEqual(netId.assetId, validPrefabGuid);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId)]
+        public void HandlerNewGuid_NoErrorWhenAssetIdIsSameAsCurrentPrefab(RegisterPrefabOverload overload)
+        {
+            Guid guid = validPrefabGuid;
+
+            CallRegisterPrefab(validPrefab, overload, guid);
+
+            Assert.IsTrue(NetworkClient.spawnHandlers.ContainsKey(guid));
+            Assert.IsTrue(NetworkClient.unspawnHandlers.ContainsKey(guid));
+
+            NetworkIdentity netId = validPrefab.GetComponent<NetworkIdentity>();
+
+            Assert.AreEqual(netId.assetId, validPrefabGuid);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab)]
+        [TestCase(RegisterPrefabOverload.Prefab_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId)]
+        public void ErrorForNullPrefab(RegisterPrefabOverload overload)
+        {
+            string msg = OverloadWithHandler(overload)
+                ? "Could not register handler for prefab because the prefab was null"
+                : "Could not register prefab because it was null";
+
+            LogAssert.Expect(LogType.Error, msg);
+            CallRegisterPrefab(null, overload);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab)]
+        [TestCase(RegisterPrefabOverload.Prefab_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId)]
+        public void ErrorForPrefabWithoutNetworkIdentity(RegisterPrefabOverload overload)
+        {
+            string msg = OverloadWithHandler(overload)
+                ? $"Could not register handler for '{invalidPrefab.name}' since it contains no NetworkIdentity component"
+                : $"Could not register '{invalidPrefab.name}' since it contains no NetworkIdentity component";
+
+            LogAssert.Expect(LogType.Error, msg);
+            CallRegisterPrefab(invalidPrefab, overload);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate_NewAssetId)]
+        public void NewGuid_ErrorForEmptyGuid(RegisterPrefabOverload overload)
+        {
+            string msg = OverloadWithHandler(overload)
+                ? $"Could not register handler for '{validPrefab.name}' with new assetId because the new assetId was empty"
+                : $"Could not register '{validPrefab.name}' with new assetId because the new assetId was empty";
+            LogAssert.Expect(LogType.Error, msg);
+            CallRegisterPrefab(validPrefab, overload, new Guid());
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        public void ErrorIfPrefabHadSceneId(RegisterPrefabOverload overload)
+        {
+            GameObject clone = GameObject.Instantiate(validPrefab);
+            NetworkIdentity netId = clone.GetComponent<NetworkIdentity>();
+            // Scene Id needs to not be zero for this test
+            netId.sceneId = 20;
+
+            LogAssert.Expect(LogType.Error, $"Can not Register '{clone.name}' because it has a sceneId, make sure you are passing in the original prefab and not an instance in the scene.");
+            CallRegisterPrefab(clone, overload);
+
+            GameObject.DestroyImmediate(clone);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        public void ErrorForNetworkIdentityInChildren(RegisterPrefabOverload overload)
+        {
+            LogAssert.Expect(LogType.Error, $"Prefab '{prefabWithChildren.name}' has multiple NetworkIdentity components. There should only be one NetworkIdentity on a prefab, and it must be on the root object.");
+            CallRegisterPrefab(prefabWithChildren, overload);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab)]
+        public void Prefab_WarningForAssetIdAlreadyExistingInPrefabsDictionary(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+
+            NetworkClient.prefabs.Add(guid, validPrefab);
+
+            LogAssert.Expect(LogType.Warning, $"Replacing existing prefab with assetId '{guid}'. Old prefab '{validPrefab.name}', New prefab '{validPrefab.name}'");
+            CallRegisterPrefab(validPrefab, overload);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        public void Handler_ErrorForAssetIdAlreadyExistingInPrefabsDictionary(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+
+            NetworkClient.prefabs.Add(guid, validPrefab);
+
+            LogAssert.Expect(LogType.Error, $"assetId '{guid}' is already used by prefab '{validPrefab.name}', unregister the prefab first before trying to add handler");
+            CallRegisterPrefab(validPrefab, overload);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        public void WarningForAssetIdAlreadyExistingInHandlersDictionary(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+
+            NetworkClient.spawnHandlers.Add(guid, x => null);
+            NetworkClient.unspawnHandlers.Add(guid, x => {});
+
+            string msg = OverloadWithHandler(overload)
+                ? $"Replacing existing spawnHandlers for prefab '{validPrefab.name}' with assetId '{guid}'"
+                : $"Adding prefab '{validPrefab.name}' with assetId '{guid}' when spawnHandlers with same assetId already exists.";
+
+            LogAssert.Expect(LogType.Warning, msg);
+            CallRegisterPrefab(validPrefab, overload);
+        }
+
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        public void SpawnDelegate_AddsHandlerToSpawnHandlers(RegisterPrefabOverload overload)
+        {
+            int handlerCalled = 0;
+
+            Guid guid = GuidForOverload(overload);
+            SpawnDelegate handler = new SpawnDelegate((pos, rot) =>
+            {
+                handlerCalled++;
+                return null;
+            });
+
+            CallRegisterPrefab(validPrefab, overload, handler);
+
+
+            Assert.IsTrue(NetworkClient.spawnHandlers.ContainsKey(guid));
+
+            // check spawnHandler above is called
+            SpawnHandlerDelegate handlerInDictionary = NetworkClient.spawnHandlers[guid];
+            handlerInDictionary.Invoke(default);
+            Assert.That(handlerCalled, Is.EqualTo(1));
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        public void SpawnDelegate_AddsHandlerToSpawnHandlersWithCorrectArguments(RegisterPrefabOverload overload)
+        {
+            int handlerCalled = 0;
+            Vector3 somePosition = new Vector3(10, 20, 3);
+
+            Guid guid = GuidForOverload(overload);
+            SpawnDelegate handler = new SpawnDelegate((pos, assetId) =>
+            {
+                handlerCalled++;
+                Assert.That(pos, Is.EqualTo(somePosition));
+                Assert.That(assetId, Is.EqualTo(guid));
+                return null;
+            });
+
+            CallRegisterPrefab(validPrefab, overload, handler);
+
+            Assert.IsTrue(NetworkClient.spawnHandlers.ContainsKey(guid));
+
+            // check spawnHandler above is called
+            SpawnHandlerDelegate handlerInDictionary = NetworkClient.spawnHandlers[guid];
+            handlerInDictionary.Invoke(new SpawnMessage { position = somePosition, assetId = guid });
+            Assert.That(handlerCalled, Is.EqualTo(1));
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate_NewAssetId)]
+        public void SpawnDelegate_ErrorWhenSpawnHandlerIsNull(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+            LogAssert.Expect(LogType.Error, $"Can not Register null SpawnHandler for {guid}");
+            CallRegisterPrefab(validPrefab, overload, spawnHandler: null);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        public void SpawnHandleDelegate_AddsHandlerToSpawnHandlers(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+
+            SpawnHandlerDelegate handler = new SpawnHandlerDelegate(x => null);
+
+            CallRegisterPrefab(validPrefab, overload, handler);
+
+            Assert.IsTrue(NetworkClient.spawnHandlers.ContainsKey(guid));
+            Assert.AreEqual(NetworkClient.spawnHandlers[guid], handler);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        public void SpawnHandleDelegate_ErrorWhenSpawnHandlerIsNull(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+            LogAssert.Expect(LogType.Error, $"Can not Register null SpawnHandler for {guid}");
+            CallRegisterPrefab(validPrefab, overload, spawnHandlerDelegate: null);
+        }
+
+        [Test]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnDelegate)]
+        [TestCase(RegisterPrefabOverload.Prefab_SpawnHandlerDelegate)]
+        public void Handler_ErrorWhenUnSpawnHandlerIsNull(RegisterPrefabOverload overload)
+        {
+            Guid guid = GuidForOverload(overload);
+            LogAssert.Expect(LogType.Error, $"Can not Register null UnSpawnHandler for {guid}");
+            CallRegisterPrefab(validPrefab, overload, unspawnHandler: null);
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_RegisterPrefab.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: bdfdcfafb85b3be418f2085e38663006
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientSceneTests_RegisterSpawnHandler.cs

@@ -0,0 +1,224 @@
+using System;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class ClientSceneTests_RegisterSpawnHandler : ClientSceneTestsBase
+    {
+        [Test]
+        public void SpawnDelegate_AddsHandlerToSpawnHandlers()
+        {
+            int handlerCalled = 0;
+
+            Guid guid = Guid.NewGuid();
+            SpawnDelegate spawnHandler = new SpawnDelegate((pos, rot) =>
+            {
+                handlerCalled++;
+                return null;
+            });
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+
+            Assert.IsTrue(NetworkClient.spawnHandlers.ContainsKey(guid));
+
+            // check spawnHandler above is called
+            SpawnHandlerDelegate handler = NetworkClient.spawnHandlers[guid];
+            handler.Invoke(default);
+            Assert.That(handlerCalled, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void SpawnDelegate_AddsHandlerToSpawnHandlersWithCorrectArguments()
+        {
+            int handlerCalled = 0;
+            Vector3 somePosition = new Vector3(10, 20, 3);
+
+            Guid guid = Guid.NewGuid();
+            SpawnDelegate spawnHandler = new SpawnDelegate((pos, assetId) =>
+            {
+                handlerCalled++;
+                Assert.That(pos, Is.EqualTo(somePosition));
+                Assert.That(assetId, Is.EqualTo(guid));
+                return null;
+            });
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+
+            Assert.IsTrue(NetworkClient.spawnHandlers.ContainsKey(guid));
+
+            // check spawnHandler above is called
+            SpawnHandlerDelegate handler = NetworkClient.spawnHandlers[guid];
+            handler.Invoke(new SpawnMessage { position = somePosition, assetId = guid });
+            Assert.That(handlerCalled, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void SpawnDelegate_AddsHandlerToUnSpawnHandlers()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+
+            Assert.IsTrue(NetworkClient.unspawnHandlers.ContainsKey(guid));
+            Assert.AreEqual(NetworkClient.unspawnHandlers[guid], unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnDelegate_ErrorWhenSpawnHandlerIsNull()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnDelegate spawnHandler = null;
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            LogAssert.Expect(LogType.Error, $"Can not Register null SpawnHandler for {guid}");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnDelegate_ErrorWhenUnSpawnHandlerIsNull()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            UnSpawnDelegate unspawnHandler = null;
+
+            LogAssert.Expect(LogType.Error, $"Can not Register null UnSpawnHandler for {guid}");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnDelegate_ErrorWhenAssetIdIsEmpty()
+        {
+            Guid guid = new Guid();
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            LogAssert.Expect(LogType.Error, "Can not Register SpawnHandler for empty Guid");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnDelegate_WarningWhenHandlerForGuidAlreadyExistsInHandlerDictionary()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+
+            SpawnDelegate spawnHandler2 = new SpawnDelegate((x, y) => new GameObject());
+            UnSpawnDelegate unspawnHandler2 = new UnSpawnDelegate(x => UnityEngine.Object.Destroy(x));
+
+            LogAssert.Expect(LogType.Warning, $"Replacing existing spawnHandlers for {guid}");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler2, unspawnHandler2);
+        }
+
+        [Test]
+        public void SpawnDelegate_ErrorWhenHandlerForGuidAlreadyExistsInPrefabDictionary()
+        {
+            Guid guid = Guid.NewGuid();
+            NetworkClient.prefabs.Add(guid, validPrefab);
+
+            SpawnDelegate spawnHandler = new SpawnDelegate((x, y) => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            LogAssert.Expect(LogType.Error, $"assetId '{guid}' is already used by prefab '{validPrefab.name}'");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+
+        [Test]
+        public void SpawnHandlerDelegate_AddsHandlerToSpawnHandlers()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnHandlerDelegate spawnHandler = new SpawnHandlerDelegate(x => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+
+            Assert.IsTrue(NetworkClient.spawnHandlers.ContainsKey(guid));
+            Assert.AreEqual(NetworkClient.spawnHandlers[guid], spawnHandler);
+        }
+
+        [Test]
+        public void SpawnHandlerDelegate_AddsHandlerToUnSpawnHandlers()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnHandlerDelegate spawnHandler = new SpawnHandlerDelegate(x => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+
+            Assert.IsTrue(NetworkClient.unspawnHandlers.ContainsKey(guid));
+            Assert.AreEqual(NetworkClient.unspawnHandlers[guid], unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnHandlerDelegate_ErrorWhenSpawnHandlerIsNull()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnHandlerDelegate spawnHandler = null;
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            LogAssert.Expect(LogType.Error, $"Can not Register null SpawnHandler for {guid}");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnHandlerDelegate_ErrorWhenUnSpawnHandlerIsNull()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnHandlerDelegate spawnHandler = new SpawnHandlerDelegate(x => null);
+            UnSpawnDelegate unspawnHandler = null;
+
+            LogAssert.Expect(LogType.Error, $"Can not Register null UnSpawnHandler for {guid}");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnHandlerDelegate_ErrorWhenAssetIdIsEmpty()
+        {
+            Guid guid = new Guid();
+            SpawnHandlerDelegate spawnHandler = new SpawnHandlerDelegate(x => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            LogAssert.Expect(LogType.Error, "Can not Register SpawnHandler for empty Guid");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+        [Test]
+        public void SpawnHandlerDelegate_WarningWhenHandlerForGuidAlreadyExistsInHandlerDictionary()
+        {
+            Guid guid = Guid.NewGuid();
+            SpawnHandlerDelegate spawnHandler = new SpawnHandlerDelegate(x => null);
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => {});
+
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+
+            SpawnHandlerDelegate spawnHandler2 = new SpawnHandlerDelegate(x => new GameObject());
+            UnSpawnDelegate unspawnHandler2 = new UnSpawnDelegate(x => UnityEngine.Object.Destroy(x));
+
+            LogAssert.Expect(LogType.Warning, $"Replacing existing spawnHandlers for {guid}");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler2, unspawnHandler2);
+        }
+
+        [Test]
+        public void SpawnHandlerDelegate_ErrorWhenHandlerForGuidAlreadyExistsInPrefabDictionary()
+        {
+            Guid guid = Guid.NewGuid();
+            NetworkClient.prefabs.Add(guid, validPrefab);
+
+            SpawnHandlerDelegate spawnHandler = new SpawnHandlerDelegate(x => new GameObject());
+            UnSpawnDelegate unspawnHandler = new UnSpawnDelegate(x => UnityEngine.Object.Destroy(x));
+
+            LogAssert.Expect(LogType.Error, $"assetId '{guid}' is already used by prefab '{validPrefab.name}'");
+            NetworkClient.RegisterSpawnHandler(guid, spawnHandler, unspawnHandler);
+        }
+
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_RegisterSpawnHandler.cs.meta

@@ -0,0 +1,11 @@
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+guid: c7e6577e8c2e64e41ae255edc61e91a2
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientSceneTests_UnregisterPrefab.cs

@@ -0,0 +1,48 @@
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class ClientSceneTests_UnregisterPrefab : ClientSceneTestsBase
+    {
+        [Test]
+        public void RemovesPrefabFromDictionary()
+        {
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+            NetworkClient.UnregisterPrefab(validPrefab);
+            Assert.IsFalse(NetworkClient.prefabs.ContainsKey(validPrefabGuid));
+        }
+
+        [Test]
+        public void RemovesSpawnHandlerFromDictionary()
+        {
+            NetworkClient.spawnHandlers.Add(validPrefabGuid, new SpawnHandlerDelegate(x => null));
+            NetworkClient.UnregisterPrefab(validPrefab);
+            Assert.IsFalse(NetworkClient.spawnHandlers.ContainsKey(validPrefabGuid));
+        }
+
+        [Test]
+        public void RemovesUnSpawnHandlerFromDictionary()
+        {
+            NetworkClient.unspawnHandlers.Add(validPrefabGuid, new UnSpawnDelegate(x => {}));
+            NetworkClient.UnregisterPrefab(validPrefab);
+            Assert.IsFalse(NetworkClient.unspawnHandlers.ContainsKey(validPrefabGuid));
+        }
+
+        [Test]
+        public void ErrorWhenPrefabIsNull()
+        {
+            LogAssert.Expect(LogType.Error, "Could not unregister prefab because it was null");
+            NetworkClient.UnregisterPrefab(null);
+        }
+
+        [Test]
+        public void ErrorWhenPrefabHasNoNetworkIdentity()
+        {
+            LogAssert.Expect(LogType.Error, $"Could not unregister '{invalidPrefab.name}' since it contains no NetworkIdentity component");
+            NetworkClient.UnregisterPrefab(invalidPrefab);
+        }
+
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_UnregisterPrefab.cs.meta

@@ -0,0 +1,11 @@
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+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ClientSceneTests_UnregisterSpawnHandler.cs

@@ -0,0 +1,33 @@
+using NUnit.Framework;
+
+namespace Mirror.Tests.ClientSceneTests
+{
+    public class ClientSceneTests_UnregisterSpawnHandler : ClientSceneTestsBase
+    {
+        [Test]
+        public void RemovesSpawnHandlersFromDictionary()
+        {
+            NetworkClient.spawnHandlers.Add(validPrefabGuid, new SpawnHandlerDelegate(x => null));
+            NetworkClient.UnregisterSpawnHandler(validPrefabGuid);
+            Assert.IsFalse(NetworkClient.unspawnHandlers.ContainsKey(validPrefabGuid));
+        }
+
+        [Test]
+        public void RemovesUnSpawnHandlersFromDictionary()
+        {
+            NetworkClient.unspawnHandlers.Add(validPrefabGuid, new UnSpawnDelegate(x => {}));
+            NetworkClient.UnregisterSpawnHandler(validPrefabGuid);
+            Assert.IsFalse(NetworkClient.unspawnHandlers.ContainsKey(validPrefabGuid));
+        }
+
+        [Test]
+        public void DoesNotRemovePrefabDictionary()
+        {
+            NetworkClient.prefabs.Add(validPrefabGuid, validPrefab);
+            NetworkClient.UnregisterSpawnHandler(validPrefabGuid);
+            // Should not be removed
+            Assert.IsTrue(NetworkClient.prefabs.ContainsKey(validPrefabGuid));
+        }
+
+    }
+}

Assets/Mirror/Tests/Editor/ClientSceneTests_UnregisterSpawnHandler.cs.meta

@@ -0,0 +1,11 @@
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+  serializedVersion: 2
+  defaultReferences: []
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+  userData: 
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+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/CommandOverrideTest.cs

@@ -0,0 +1,182 @@
+using System;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests.RemoteAttrributeTest
+{
+    class VirtualCommand : NetworkBehaviour
+    {
+        public event Action<int> onVirtualSendInt;
+
+        [Command]
+        public virtual void CmdSendInt(int someInt) =>
+            onVirtualSendInt?.Invoke(someInt);
+    }
+
+    class VirtualNoOverrideCommand : VirtualCommand {}
+
+    class VirtualOverrideCommand : VirtualCommand
+    {
+        public event Action<int> onOverrideSendInt;
+
+        [Command]
+        public override void CmdSendInt(int someInt) =>
+            onOverrideSendInt?.Invoke(someInt);
+    }
+
+    class VirtualOverrideCommandWithBase : VirtualCommand
+    {
+        public event Action<int> onOverrideSendInt;
+
+        [Command]
+        public override void CmdSendInt(int someInt)
+        {
+            base.CmdSendInt(someInt);
+            onOverrideSendInt?.Invoke(someInt);
+        }
+    }
+
+    // test for 2 overrides
+    class VirtualOverrideCommandWithBase2 : VirtualOverrideCommandWithBase
+    {
+        public event Action<int> onOverrideSendInt2;
+
+        [Command]
+        public override void CmdSendInt(int someInt)
+        {
+            base.CmdSendInt(someInt);
+            onOverrideSendInt2?.Invoke(someInt);
+        }
+    }
+
+    public class CommandOverrideTest : RemoteTestBase
+    {
+        [Test]
+        public void VirtualCommandIsCalled()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualCommand hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void VirtualCommandWithNoOverrideIsCalled()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualNoOverrideCommand hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void OverrideVirtualCommandIsCalled()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualOverrideCommand hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            int overrideCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+            };
+            hostBehaviour.onOverrideSendInt += incomingInt =>
+            {
+                overrideCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(0));
+            Assert.That(overrideCallCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void OverrideVirtualWithBaseCallsBothVirtualAndBase()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualOverrideCommandWithBase hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            int overrideCallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.onOverrideSendInt += incomingInt =>
+            {
+                overrideCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(1));
+            Assert.That(overrideCallCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void OverrideVirtualWithBaseCallsAllMethodsThatCallBase()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out VirtualOverrideCommandWithBase2 hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int virtualCallCount = 0;
+            int overrideCallCount = 0;
+            int override2CallCount = 0;
+            hostBehaviour.onVirtualSendInt += incomingInt =>
+            {
+                virtualCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.onOverrideSendInt += incomingInt =>
+            {
+                overrideCallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.onOverrideSendInt2 += incomingInt =>
+            {
+                override2CallCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+
+
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(virtualCallCount, Is.EqualTo(1));
+            Assert.That(overrideCallCount, Is.EqualTo(1));
+            Assert.That(override2CallCount, Is.EqualTo(1));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/CommandOverrideTest.cs.meta

@@ -0,0 +1,11 @@
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+  defaultReferences: []
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+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/CommandTest.cs

@@ -0,0 +1,247 @@
+using System;
+using System.Text.RegularExpressions;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Mirror.Tests.RemoteAttrributeTest
+{
+    class AuthorityBehaviour : NetworkBehaviour
+    {
+        public event Action<int> onSendInt;
+
+        [Command]
+        public void SendInt(int someInt) =>
+            onSendInt?.Invoke(someInt);
+    }
+
+    class IgnoreAuthorityBehaviour : NetworkBehaviour
+    {
+        public event Action<int> onSendInt;
+
+        [Command(requiresAuthority = false)]
+        public void CmdSendInt(int someInt) =>
+            onSendInt?.Invoke(someInt);
+    }
+
+    class SenderConnectionBehaviour : NetworkBehaviour
+    {
+        public event Action<int, NetworkConnection> onSendInt;
+
+        [Command]
+        public void CmdSendInt(int someInt, NetworkConnectionToClient conn = null) =>
+            onSendInt?.Invoke(someInt, conn);
+    }
+
+    class SenderConnectionIgnoreAuthorityBehaviour : NetworkBehaviour
+    {
+        public event Action<int, NetworkConnection> onSendInt;
+
+        [Command(requiresAuthority = false)]
+        public void CmdSendInt(int someInt, NetworkConnectionToClient conn = null) =>
+            onSendInt?.Invoke(someInt, conn);
+    }
+
+    class ThrowBehaviour : NetworkBehaviour
+    {
+        public const string ErrorMessage = "Bad things happened";
+
+        [Command]
+        public void SendThrow(int _) => throw new Exception(ErrorMessage);
+    }
+
+    class CommandOverloads : NetworkBehaviour
+    {
+        public int firstCalled = 0;
+        public int secondCalled = 0;
+
+        [Command]
+        public void TheCommand(int _) => ++firstCalled;
+
+        [Command]
+        public void TheCommand(string _) => ++secondCalled;
+    }
+
+    public class CommandTest : RemoteTestBase
+    {
+        [Test]
+        public void CommandIsSentWithAuthority()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out _, out _, out AuthorityBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int callCount = 0;
+            hostBehaviour.onSendInt += incomingInt =>
+            {
+                callCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.SendInt(someInt);
+            ProcessMessages();
+            Assert.That(callCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void WarningForCommandSentWithoutAuthority()
+        {
+            // spawn without owner
+            CreateNetworkedAndSpawn(out _, out _, out AuthorityBehaviour hostBehaviour);
+
+            const int someInt = 20;
+
+            int callCount = 0;
+            hostBehaviour.onSendInt += incomingInt =>
+            {
+                callCount++;
+            };
+            LogAssert.Expect(LogType.Warning, $"Trying to send command for object without authority. System.Void Mirror.Tests.RemoteAttrributeTest.AuthorityBehaviour::SendInt(System.Int32)");
+            hostBehaviour.SendInt(someInt);
+            ProcessMessages();
+            Assert.That(callCount, Is.Zero);
+        }
+
+
+        [Test]
+        public void CommandIsSentWithAuthorityWhenIgnoringAuthority()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out _, out _, out IgnoreAuthorityBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+
+            int callCount = 0;
+            hostBehaviour.onSendInt += incomingInt =>
+            {
+                callCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(callCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void CommandIsSentWithoutAuthorityWhenIgnoringAuthority()
+        {
+            // spawn without owner
+            CreateNetworkedAndSpawn(out _, out _, out IgnoreAuthorityBehaviour hostBehaviour);
+
+            const int someInt = 20;
+
+            int callCount = 0;
+            hostBehaviour.onSendInt += incomingInt =>
+            {
+                callCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+            };
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(callCount, Is.EqualTo(1));
+        }
+
+        // test to prevent https://github.com/vis2k/Mirror/issues/2629
+        // from happening again in the future
+        // -> [Command]s can be called on other objects with requiresAuthority=false.
+        // -> those objects don't have a .connectionToServer
+        // -> we broke it when using .connectionToServer instead of
+        //    NetworkClient.connection in SendCommandInternal.
+        [Test]
+        public void Command_RequiresAuthorityFalse_ForOtherObjectWithoutConnectionToServer()
+        {
+            // spawn without owner (= without connectionToClient)
+            CreateNetworkedAndSpawn(out _, out _, out IgnoreAuthorityBehaviour comp);
+
+            // setup callback
+            int called = 0;
+            comp.onSendInt += _ => { ++called; };
+
+            // call command. don't require authority.
+            // the object doesn't have a .connectionToServer (like a scene object)
+            Assert.That(comp.connectionToServer, Is.Null);
+            comp.CmdSendInt(0);
+            Assert.That(called, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void SenderConnectionIsSetWhenCommandIsRecieved()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out _, out _, out SenderConnectionBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+            NetworkConnectionToClient connectionToClient = NetworkServer.connections[0];
+            Debug.Assert(connectionToClient != null, $"connectionToClient was null, This means that the test is broken and will give the wrong results");
+
+
+            int callCount = 0;
+            hostBehaviour.onSendInt += (incomingInt, incomingConn) =>
+            {
+                callCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+                Assert.That(incomingConn, Is.EqualTo(connectionToClient));
+            };
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(callCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void SenderConnectionIsSetWhenCommandIsRecievedWithIgnoreAuthority()
+        {
+            // spawn without owner
+            CreateNetworkedAndSpawn(out _, out _, out SenderConnectionIgnoreAuthorityBehaviour hostBehaviour);
+
+            const int someInt = 20;
+            NetworkConnectionToClient connectionToClient = NetworkServer.connections[0];
+            Debug.Assert(connectionToClient != null, $"connectionToClient was null, This means that the test is broken and will give the wrong results");
+
+            int callCount = 0;
+            hostBehaviour.onSendInt += (incomingInt, incomingConn) =>
+            {
+                callCount++;
+                Assert.That(incomingInt, Is.EqualTo(someInt));
+                Assert.That(incomingConn, Is.EqualTo(connectionToClient));
+            };
+            hostBehaviour.CmdSendInt(someInt);
+            ProcessMessages();
+            Assert.That(callCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void CommandThatThrowsShouldBeCaught()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out _, out _, out ThrowBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            const int someInt = 20;
+            NetworkConnectionToClient connectionToClient = NetworkServer.connections[0];
+            Debug.Assert(connectionToClient != null, $"connectionToClient was null, This means that the test is broken and will give the wrong results");
+
+            LogAssert.Expect(LogType.Error, new Regex($".*{ThrowBehaviour.ErrorMessage}.*"));
+            Assert.DoesNotThrow(() =>
+            {
+                hostBehaviour.SendThrow(someInt);
+                ProcessMessages();
+            }, "Processing new message should not throw, the exception from SendThrow should be caught");
+        }
+
+        // RemoteCalls uses md.FullName which gives us the full command/rpc name
+        // like "System.Void Mirror.Tests.RemoteAttrributeTest.AuthorityBehaviour::SendInt(System.Int32)"
+        // which means overloads with same name but different types should work.
+        [Test]
+        public void CommandOverloads()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out _, out _, out CommandOverloads comp, NetworkServer.localConnection);
+
+            // call both overloads once
+            comp.TheCommand(42);
+            comp.TheCommand("A");
+            ProcessMessages();
+            Assert.That(comp.firstCalled, Is.EqualTo(1));
+            Assert.That(comp.secondCalled, Is.EqualTo(1));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/CommandTest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 1dd3f8a95eee6f74997bc8abcd43a401
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/CompressionTests.cs

@@ -0,0 +1,257 @@
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public class CompressionTests
+    {
+        [Test]
+        public void LargestAbsoluteComponentIndex()
+        {
+            // positive value & xyw smallest
+            Vector4 value = new Vector4(1, 3, 4, 2);
+            int index = Compression.LargestAbsoluteComponentIndex(value, out float largest, out Vector3 withoutLargest);
+            Assert.That(index, Is.EqualTo(2));
+            Assert.That(largest, Is.EqualTo(Mathf.Abs(value.z)));
+            Assert.That(withoutLargest, Is.EqualTo(new Vector3(value.x, value.y, value.w)));
+
+            // negative value should use abs & xzw smallest
+            value = new Vector4(1, -5, 4, 0);
+            index = Compression.LargestAbsoluteComponentIndex(value, out largest, out withoutLargest);
+            Assert.That(index, Is.EqualTo(1));
+            Assert.That(largest, Is.EqualTo(Mathf.Abs(value.y)));
+            Assert.That(withoutLargest, Is.EqualTo(new Vector3(value.x, value.z, value.w)));
+
+            // positive value & yzw smallest
+            value = new Vector4(5, 2, 3, 4);
+            index = Compression.LargestAbsoluteComponentIndex(value, out largest, out withoutLargest);
+            Assert.That(index, Is.EqualTo(0));
+            Assert.That(largest, Is.EqualTo(Mathf.Abs(value.x)));
+            Assert.That(withoutLargest, Is.EqualTo(new Vector3(value.y, value.z, value.w)));
+
+            // test to guarantee it uses 'abs' for first value
+            // to reproduce https://github.com/vis2k/Mirror/issues/2674
+            // IF all values are properly 'abs', THEN first one should be largest
+            value = new Vector4(-3, 0, 1, 2);
+            index = Compression.LargestAbsoluteComponentIndex(value, out largest, out withoutLargest);
+            Assert.That(index, Is.EqualTo(0));
+            Assert.That(largest, Is.EqualTo(Mathf.Abs(value.x)));
+            Assert.That(withoutLargest, Is.EqualTo(new Vector3(value.y, value.z, value.w)));
+        }
+
+        [Test, Ignore("Enable when needed.")]
+        public void LargestAbsoluteComponentIndexBenchmark()
+        {
+            Vector4 value = new Vector4(1, 2, 3, 4);
+            for (int i = 0; i < 100000; ++i)
+                Compression.LargestAbsoluteComponentIndex(value, out float _, out Vector3 _);
+        }
+
+        [Test]
+        public void ScaleFloatToUShort()
+        {
+            Assert.That(Compression.ScaleFloatToUShort(-1f, -1f, 1f, ushort.MinValue, ushort.MaxValue), Is.EqualTo(0));
+            Assert.That(Compression.ScaleFloatToUShort(0f, -1f, 1f, ushort.MinValue, ushort.MaxValue), Is.EqualTo(32767));
+            Assert.That(Compression.ScaleFloatToUShort(0.5f, -1f, 1f, ushort.MinValue, ushort.MaxValue), Is.EqualTo(49151));
+            Assert.That(Compression.ScaleFloatToUShort(1f, -1f, 1f, ushort.MinValue, ushort.MaxValue), Is.EqualTo(65535));
+        }
+
+        [Test]
+        public void ScaleUShortToFloat()
+        {
+            Assert.That(Compression.ScaleUShortToFloat(0, ushort.MinValue, ushort.MaxValue, -1, 1), Is.EqualTo(-1).Within(0.0001f));
+            Assert.That(Compression.ScaleUShortToFloat(32767, ushort.MinValue, ushort.MaxValue, -1, 1), Is.EqualTo(-0f).Within(0.0001f));
+            Assert.That(Compression.ScaleUShortToFloat(49151, ushort.MinValue, ushort.MaxValue, -1, 1), Is.EqualTo(0.5f).Within(0.0001f));
+            Assert.That(Compression.ScaleUShortToFloat(65535, ushort.MinValue, ushort.MaxValue, -1, 1), Is.EqualTo(1).Within(0.0001f));
+        }
+
+        [Test]
+        public void CompressAndDecompressQuaternion()
+        {
+            // we need a normalized value
+            Quaternion value = new Quaternion(1, 3, 4, 2).normalized;
+
+            // compress
+            uint data = Compression.CompressQuaternion(value);
+            Assert.That(data, Is.EqualTo(0xA83E2F07));
+
+            // decompress
+            Quaternion decompressed = Compression.DecompressQuaternion(data);
+            Assert.That(decompressed.x, Is.EqualTo(value.x).Within(0.005f));
+            Assert.That(decompressed.y, Is.EqualTo(value.y).Within(0.005f));
+            Assert.That(decompressed.z, Is.EqualTo(value.z).Within(0.005f));
+            Assert.That(decompressed.w, Is.EqualTo(value.w).Within(0.005f));
+        }
+
+        // iterate all [0..360] euler angles for x, y, z
+        // to make sure it all works and we missed nothing.
+        [Test]
+        public void CompressAndDecompressQuaternion_Iterate_0_to_360()
+        {
+            // stepSize  1: 360 * 360 * 360 =  46 million  [takes 96 s]
+            // stepSize  5:  72 *  72 *  72 = 373 thousand [takes 700 ms]
+            // stepSize 10:  36 *  36 *  36 =  46 thousand [takes 100 ms]
+            //
+            // => 10 is enough. 700ms accumulates in hours of time waited over
+            //    the years..
+            const int stepSize = 10;
+
+            for (int x = 0; x <= 360; x += stepSize)
+            {
+                for (int y = 0; y <= 360; y += stepSize)
+                {
+                    for (int z = 0; z <= 360; z += stepSize)
+                    {
+                        // we need a normalized value
+                        Quaternion value = Quaternion.Euler(x, y, z).normalized;
+
+                        // compress
+                        uint data = Compression.CompressQuaternion(value);
+
+                        // decompress
+                        Quaternion decompressed = Compression.DecompressQuaternion(data);
+
+                        // compare them. Quaternion.Angle is easiest to get the angle
+                        // between them. using .eulerAngles would give 0, 90, 360 which is
+                        // hard to compare.
+                        float angle = Quaternion.Angle(value, decompressed);
+                        // 1 degree tolerance
+                        Assert.That(Mathf.Abs(angle), Is.LessThanOrEqualTo(1));
+                    }
+                }
+            }
+        }
+
+        // someone mentioned issues with 90 degree euler becoming -90 degree
+        [Test]
+        public void CompressAndDecompressQuaternion_90DegreeEuler()
+        {
+            // we need a normalized value
+            Quaternion value = Quaternion.Euler(0, 90, 0).normalized;
+
+            // compress
+            uint data = Compression.CompressQuaternion(value);
+
+            // decompress
+            Quaternion decompressed = Compression.DecompressQuaternion(data);
+
+            // compare them. Quaternion.Angle is easiest to get the angle
+            // between them. using .eulerAngles would give 0, 90, 360 which is
+            // hard to compare.
+            Debug.Log($"euler={decompressed.eulerAngles}");
+            float angle = Quaternion.Angle(value, decompressed);
+            // 1 degree tolerance
+            Assert.That(Mathf.Abs(angle), Is.LessThanOrEqualTo(1));
+        }
+
+        // test for issue https://github.com/vis2k/Mirror/issues/2674
+        [Test]
+        public void CompressAndDecompressQuaternion_2674()
+        {
+            // we need a normalized value
+            Quaternion value = Quaternion.Euler(338.850037f, 170.609955f, 182.979996f).normalized;
+            Debug.Log($"original={value.eulerAngles}");
+
+            // compress
+            uint data = Compression.CompressQuaternion(value);
+
+            // decompress
+            Quaternion decompressed = Compression.DecompressQuaternion(data);
+
+            // compare them. Quaternion.Angle is easiest to get the angle
+            // between them. using .eulerAngles would give 0, 90, 360 which is
+            // hard to compare.
+
+            //  (51.6, 355.5, 348.1)
+            Debug.Log($"euler={decompressed.eulerAngles}");
+            float angle = Quaternion.Angle(value, decompressed);
+            // 1 degree tolerance
+            Assert.That(Mathf.Abs(angle), Is.LessThanOrEqualTo(1));
+        }
+
+        // client sending invalid data should still produce valid quaternions to
+        // avoid any possible bugs on server
+        [Test]
+        public void DecompressQuaternionInvalidData()
+        {
+            // decompress
+            // 0xFFFFFFFF will decompress to (0.7, 0.7, 0.7, NaN)
+            Quaternion decompressed = Compression.DecompressQuaternion(0xFFFFFFFF);
+            Assert.That(decompressed, Is.EqualTo(Quaternion.identity));
+        }
+
+        [Test]
+        public void VarInt()
+        {
+            NetworkWriter writer = new NetworkWriter();
+            Compression.CompressVarUInt(writer, 0);
+            Compression.CompressVarUInt(writer, 234);
+            Compression.CompressVarUInt(writer, 2284);
+            Compression.CompressVarUInt(writer, 67821);
+            Compression.CompressVarUInt(writer, 16777210);
+            Compression.CompressVarUInt(writer, 16777219);
+            Compression.CompressVarUInt(writer, 4294967295);
+            Compression.CompressVarUInt(writer, 1099511627775);
+            Compression.CompressVarUInt(writer, 281474976710655);
+            Compression.CompressVarUInt(writer, 72057594037927935);
+            Compression.CompressVarUInt(writer, ulong.MaxValue);
+
+            Compression.CompressVarInt(writer, long.MinValue);
+            Compression.CompressVarInt(writer, -72057594037927935);
+            Compression.CompressVarInt(writer, -281474976710655);
+            Compression.CompressVarInt(writer, -1099511627775);
+            Compression.CompressVarInt(writer, -4294967295);
+            Compression.CompressVarInt(writer, -16777219);
+            Compression.CompressVarInt(writer, -16777210);
+            Compression.CompressVarInt(writer, -67821);
+            Compression.CompressVarInt(writer, -2284);
+            Compression.CompressVarInt(writer, -234);
+            Compression.CompressVarInt(writer, 0);
+            Compression.CompressVarInt(writer, 234);
+            Compression.CompressVarInt(writer, 2284);
+            Compression.CompressVarInt(writer, 67821);
+            Compression.CompressVarInt(writer, 16777210);
+            Compression.CompressVarInt(writer, 16777219);
+            Compression.CompressVarInt(writer, 4294967295);
+            Compression.CompressVarInt(writer, 1099511627775);
+            Compression.CompressVarInt(writer, 281474976710655);
+            Compression.CompressVarInt(writer, 72057594037927935);
+            Compression.CompressVarInt(writer, long.MaxValue);
+
+            NetworkReader reader = new NetworkReader(writer.ToArray());
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(0));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(234));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(2284));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(67821));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(16777210));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(16777219));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(4294967295));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(1099511627775));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(281474976710655));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(72057594037927935));
+            Assert.That(Compression.DecompressVarUInt(reader), Is.EqualTo(ulong.MaxValue));
+
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(long.MinValue));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-72057594037927935));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-281474976710655));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-1099511627775));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-4294967295));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-16777219));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-16777210));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-67821));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-2284));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(-234));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(0));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(234));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(2284));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(67821));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(16777210));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(16777219));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(4294967295));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(1099511627775));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(281474976710655));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(72057594037927935));
+            Assert.That(Compression.DecompressVarInt(reader), Is.EqualTo(long.MaxValue));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/CompressionTests.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 541cf2bc89fe4395b2a50d921c91424a
+timeCreated: 1613190697

Assets/Mirror/Tests/Editor/CustomRWTest.cs

@@ -0,0 +1,53 @@
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public class MockQuest
+    {
+        public int Id;
+
+        public MockQuest(int id)
+        {
+            Id = id;
+        }
+
+        public MockQuest()
+        {
+            Id = 0;
+        }
+    }
+
+    public static class MockQuestReaderWriter
+    {
+        public static void WriteQuest(this NetworkWriter writer, MockQuest quest)
+        {
+            writer.WriteInt(quest.Id);
+        }
+        public static MockQuest WriteQuest(this NetworkReader reader)
+        {
+            return new MockQuest(reader.ReadInt());
+        }
+    }
+
+    [TestFixture]
+    public class CustomRWTest
+    {
+        public struct QuestMessage : NetworkMessage
+        {
+            public MockQuest quest;
+        }
+
+        [Test]
+        public void TestCustomRW()
+        {
+            QuestMessage message = new QuestMessage
+            {
+                quest = new MockQuest(100)
+            };
+
+            byte[] data = MessagePackingTest.PackToByteArray(message);
+            QuestMessage unpacked = MessagePackingTest.UnpackFromByteArray<QuestMessage>(data);
+            Assert.That(unpacked.quest.Id, Is.EqualTo(100));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/CustomRWTest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 3d74d53ca2c8c4b1195833376f9f6bb6
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
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+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/EnumReadWriteTests.cs

@@ -0,0 +1,91 @@
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public static class MyCustomEnumReadWrite
+    {
+        public static void WriteMyCustomEnum(this NetworkWriter networkWriter, EnumReadWriteTests.MyCustomEnum customEnum)
+        {
+            // if O write N
+            if (customEnum == EnumReadWriteTests.MyCustomEnum.O)
+            {
+                networkWriter.WriteInt((int)EnumReadWriteTests.MyCustomEnum.N);
+            }
+            else
+            {
+                networkWriter.WriteInt((int)customEnum);
+            }
+        }
+        public static EnumReadWriteTests.MyCustomEnum ReadMyCustomEnum(this NetworkReader networkReader)
+        {
+            return (EnumReadWriteTests.MyCustomEnum)networkReader.ReadInt();
+        }
+    }
+    public class EnumReadWriteTests
+    {
+        public struct ByteMessage : NetworkMessage { public MyByteEnum byteEnum; }
+        public enum MyByteEnum : byte
+        {
+            A, B, C, D
+        }
+
+        public struct ShortMessage : NetworkMessage { public MyShortEnum shortEnum; }
+        public enum MyShortEnum : short
+        {
+            E, F, G, H
+        }
+
+        public struct CustomMessage : NetworkMessage { public MyCustomEnum customEnum; }
+
+        public enum MyCustomEnum
+        {
+            M, N, O, P
+        }
+
+
+        [Test]
+        public void ByteIsSentForByteEnum()
+        {
+            ByteMessage msg = new ByteMessage() { byteEnum = MyByteEnum.B };
+
+            NetworkWriter writer = new NetworkWriter();
+            writer.Write(msg);
+
+            // should be 1 byte for data
+            Assert.That(writer.Position, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void ShortIsSentForShortEnum()
+        {
+            ShortMessage msg = new ShortMessage() { shortEnum = MyShortEnum.G };
+
+            NetworkWriter writer = new NetworkWriter();
+            writer.Write(msg);
+
+            // should be 2 bytes for data
+            Assert.That(writer.Position, Is.EqualTo(2));
+        }
+
+        [Test]
+        public void CustomWriterIsUsedForEnum()
+        {
+            CustomMessage serverMsg = new CustomMessage() { customEnum = MyCustomEnum.O };
+            CustomMessage clientMsg = SerializeAndDeserializeMessage(serverMsg);
+
+            // custom writer should write N if it sees O
+            Assert.That(clientMsg.customEnum, Is.EqualTo(MyCustomEnum.N));
+        }
+        T SerializeAndDeserializeMessage<T>(T msg)
+            where T : struct, NetworkMessage
+        {
+            NetworkWriter writer = new NetworkWriter();
+
+            writer.Write(msg);
+
+            NetworkReader reader = new NetworkReader(writer.ToArraySegment());
+
+            return reader.Read<T>();
+        }
+    }
+}

Assets/Mirror/Tests/Editor/EnumReadWriteTests.cs.meta

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+  defaultReferences: []
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/ExponentialMovingAverageTest.cs

@@ -0,0 +1,42 @@
+using NUnit.Framework;
+namespace Mirror.Tests
+{
+    [TestFixture]
+    public class ExponentialMovingAverageTest
+    {
+        [Test]
+        public void TestInitial()
+        {
+            ExponentialMovingAverage ema = new ExponentialMovingAverage(10);
+
+            ema.Add(3);
+
+            Assert.That(ema.Value, Is.EqualTo(3));
+            Assert.That(ema.Var, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void TestMovingAverage()
+        {
+            ExponentialMovingAverage ema = new ExponentialMovingAverage(10);
+
+            ema.Add(5);
+            ema.Add(6);
+
+            Assert.That(ema.Value, Is.EqualTo(5.1818).Within(0.0001f));
+            Assert.That(ema.Var, Is.EqualTo(0.1487).Within(0.0001f));
+        }
+
+        [Test]
+        public void TestVar()
+        {
+            ExponentialMovingAverage ema = new ExponentialMovingAverage(10);
+
+            ema.Add(5);
+            ema.Add(6);
+            ema.Add(7);
+
+            Assert.That(ema.Var, Is.EqualTo(0.6134).Within(0.0001f));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ExponentialMovingAverageTest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 8e3f2ecadd13149f29cd3e83ef6a4bff
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Assets/Mirror/Tests/Editor/ExtensionsTest.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using System.Linq;
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public class ExtensionsTest
+    {
+        // supposed to return same result on all platforms
+        [Test]
+        public void GetStableHashHode()
+        {
+            Assert.That("".GetStableHashCode(), Is.EqualTo(23));
+            Assert.That("Test".GetStableHashCode(), Is.EqualTo(23844169));
+        }
+
+        [Test]
+        public void CopyToList()
+        {
+            List<int> source = new List<int>{1, 2, 3};
+            List<int> destination = new List<int>();
+            source.CopyTo(destination);
+            Assert.That(destination.SequenceEqual(source), Is.True);
+        }
+    }
+}

Assets/Mirror/Tests/Editor/ExtensionsTest.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 21e1452d6f734618a9364a2c6c116922
+timeCreated: 1621762116

Assets/Mirror/Tests/Editor/FieldsInBaseClasses.cs

@@ -0,0 +1,56 @@
+using System;
+using Mirror.Tests.RemoteAttrributeTest;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests.GeneratedWriterTests
+{
+    public class BaseData
+    {
+        public bool toggle;
+    }
+    public class SomeOtherData : BaseData
+    {
+        public int usefulNumber;
+    }
+
+    public class DataSenderBehaviour : NetworkBehaviour
+    {
+        public event Action<SomeOtherData> onData;
+
+        [Command]
+        public void CmdSendData(SomeOtherData otherData)
+        {
+            onData?.Invoke(otherData);
+        }
+    }
+
+    public class FieldsInBaseClasses : RemoteTestBase
+    {
+        [Test, Ignore("Destroy is needed for the code. Can't be called in Edit mode.")]
+        public void WriterShouldIncludeFieldsInBaseClass()
+        {
+            // spawn with owner
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out DataSenderBehaviour hostBehaviour, NetworkServer.localConnection);
+
+            const bool toggle = true;
+            const int usefulNumber = 10;
+
+            int called = 0;
+            hostBehaviour.onData += data =>
+            {
+                called++;
+                Assert.That(data.usefulNumber, Is.EqualTo(usefulNumber));
+                Assert.That(data.toggle, Is.EqualTo(toggle));
+            };
+            hostBehaviour.CmdSendData(new SomeOtherData
+            {
+                usefulNumber = usefulNumber,
+                toggle = toggle
+            });
+
+            ProcessMessages();
+            Assert.That(called, Is.EqualTo(1));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/FieldsInBaseClasses.cs.meta

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Assets/Mirror/Tests/Editor/Generated.meta

@@ -0,0 +1,8 @@
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+folderAsset: yes
+DefaultImporter:
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+  userData: 
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Assets/Mirror/Tests/Editor/Generated/AttritubeTest.gen.cs.meta

@@ -0,0 +1,11 @@
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Assets/Mirror/Tests/Editor/Generated/CollectionWriterTests.gen.cs.meta

@@ -0,0 +1,11 @@
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Assets/Mirror/Tests/Editor/Grid2DTests.cs

@@ -0,0 +1,58 @@
+using System.Collections.Generic;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public class Grid2DTests
+    {
+        Grid2D<int> grid = new Grid2D<int>();
+
+        [Test]
+        public void AddAndGetNeighbours()
+        {
+            // add two at (0, 0)
+            grid.Add(Vector2Int.zero, 1);
+            grid.Add(Vector2Int.zero, 2);
+            HashSet<int> result = new HashSet<int>();
+            grid.GetWithNeighbours(Vector2Int.zero, result);
+            Assert.That(result.Count, Is.EqualTo(2));
+            Assert.That(result.Contains(1), Is.True);
+            Assert.That(result.Contains(2), Is.True);
+
+            // add a neighbour at (1, 1)
+            grid.Add(new Vector2Int(1, 1), 3);
+            grid.GetWithNeighbours(Vector2Int.zero, result);
+            Assert.That(result.Count, Is.EqualTo(3));
+            Assert.That(result.Contains(1), Is.True);
+            Assert.That(result.Contains(2), Is.True);
+            Assert.That(result.Contains(3), Is.True);
+        }
+
+        [Test]
+        public void GetIgnoresTooFarNeighbours()
+        {
+            // add at (0, 0)
+            grid.Add(Vector2Int.zero, 1);
+
+            // get at (2, 0) which is out of 9 neighbour radius
+            HashSet<int> result = new HashSet<int>();
+            grid.GetWithNeighbours(new Vector2Int(2, 0), result);
+            Assert.That(result.Count, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void ClearNonAlloc()
+        {
+            // add some
+            grid.Add(Vector2Int.zero, 1);
+            grid.Add(Vector2Int.zero, 2);
+
+            // clear and check if empty now
+            grid.ClearNonAlloc();
+            HashSet<int> result = new HashSet<int>();
+            grid.GetWithNeighbours(Vector2Int.zero, result);
+            Assert.That(result.Count, Is.EqualTo(0));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/Grid2DTests.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: f8f3c4f37bb54824b5dfe70e0984b3d3
+timeCreated: 1613188745

Assets/Mirror/Tests/Editor/InterestManagementTests_Common.cs

@@ -0,0 +1,95 @@
+// default = no component = everyone sees everyone
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public abstract class InterestManagementTests_Common : MirrorEditModeTest
+    {
+        protected GameObject gameObjectA;
+        protected NetworkIdentity identityA;
+        protected NetworkConnectionToClient connectionA;
+
+        protected GameObject gameObjectB;
+        protected NetworkIdentity identityB;
+        protected NetworkConnectionToClient connectionB;
+
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+
+            // A with connectionId = 0x0A, netId = 0xAA
+            CreateNetworked(out gameObjectA, out identityA);
+            connectionA = new NetworkConnectionToClient(0x0A);
+            connectionA.isAuthenticated = true;
+            connectionA.isReady = true;
+            connectionA.identity = identityA;
+            NetworkServer.spawned[0xAA] = identityA;
+
+            // B
+            CreateNetworked(out gameObjectB, out identityB);
+            connectionB = new NetworkConnectionToClient(0x0B);
+            connectionB.isAuthenticated = true;
+            connectionB.isReady = true;
+            connectionB.identity = identityB;
+            NetworkServer.spawned[0xBB] = identityB;
+
+            // need to start server so that interest management works
+            NetworkServer.Listen(10);
+
+            // add both connections
+            NetworkServer.connections[connectionA.connectionId] = connectionA;
+            NetworkServer.connections[connectionB.connectionId] = connectionB;
+
+            // spawn both so that .observers is created
+            NetworkServer.Spawn(gameObjectA, connectionA);
+            NetworkServer.Spawn(gameObjectB, connectionB);
+
+            // spawn already runs interest management once
+            // clear observers and observing so tests can start from scratch
+            identityA.observers.Clear();
+            identityB.observers.Clear();
+            connectionA.observing.Clear();
+            connectionB.observing.Clear();
+        }
+
+        [TearDown]
+        public override void TearDown()
+        {
+            // set isServer is false. otherwise Destroy instead of
+            // DestroyImmediate is called internally, giving an error in Editor
+            identityA.isServer = false;
+
+            // set isServer is false. otherwise Destroy instead of
+            // DestroyImmediate is called internally, giving an error in Editor
+            identityB.isServer = false;
+
+            // clear connections first. calling OnDisconnect wouldn't work since
+            // we have no real clients.
+            NetworkServer.connections.Clear();
+
+            base.TearDown();
+        }
+
+        // player should always see self no matter what
+        [Test]
+        public void PlayerAlwaysSeesSelf_Initial()
+        {
+            // rebuild for A
+            // initial rebuild adds all connections if no interest management available
+            NetworkServer.RebuildObservers(identityA, true);
+
+            // should see self
+            Assert.That(identityA.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // forceHidden should still work
+        [Test]
+        public abstract void ForceHidden_Initial();
+
+        // forceShown should still work
+        [Test]
+        public abstract void ForceShown_Initial();
+    }
+}

Assets/Mirror/Tests/Editor/InterestManagementTests_Common.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: f0349d2e3a74454e9dc8badec1db0289
+timeCreated: 1613049868

Assets/Mirror/Tests/Editor/InterestManagementTests_Default.cs

@@ -0,0 +1,62 @@
+// default = no component = everyone sees everyone
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public class InterestManagementTests_Default : InterestManagementTests_Common
+    {
+        // no interest management (default)
+        // => forceHidden should still work
+        [Test]
+        public override void ForceHidden_Initial()
+        {
+            // force hide A
+            identityA.visible = Visibility.ForceHidden;
+
+            // rebuild for both
+            // initial rebuild adds all connections if no interest management available
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // A should not be seen by B because A is force hidden
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.False);
+            // B should be seen by A because
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // no interest management (default)
+        // => forceShown should still work
+        [Test]
+        public override void ForceShown_Initial()
+        {
+            // force show A
+            identityA.visible = Visibility.ForceShown;
+
+            // rebuild for both
+            // initial rebuild adds all connections if no interest management available
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // both should see each other because by default, everyone sees everyone
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // no interest management (default)
+        // => everyone should see everyone
+        [Test]
+        public void EveryoneSeesEveryone_Initial()
+        {
+            // rebuild for both
+            // initial rebuild adds all connections if no interest management available
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // both should see each other
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // TODO add tests to make sure old observers are removed etc.
+    }
+}

Assets/Mirror/Tests/Editor/InterestManagementTests_Default.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: c5ac1fc2c25043378f80bc02d868a5d6
+timeCreated: 1613042576

Assets/Mirror/Tests/Editor/InterestManagementTests_Distance.cs

@@ -0,0 +1,142 @@
+// Vector3.Distance based
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public class InterestManagementTests_Distance : InterestManagementTests_Common
+    {
+        DistanceInterestManagement aoi;
+
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+
+            // create AOI GameObject
+            CreateGameObject(out GameObject go, out aoi);
+            aoi.visRange = 10;
+            // setup server aoi since InterestManagement Awake isn't called
+            NetworkServer.aoi = aoi;
+        }
+
+        [TearDown]
+        public override void TearDown()
+        {
+            base.TearDown();
+            // clear server aoi again
+            NetworkServer.aoi = null;
+        }
+
+        // brute force interest management
+        // => forceHidden should still work
+        [Test]
+        public override void ForceHidden_Initial()
+        {
+            // A and B are at (0,0,0) so within range!
+
+            // force hide A
+            identityA.visible = Visibility.ForceHidden;
+
+            // rebuild for both
+            // initial rebuild while both are within range
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // A should not be seen by B because A is force hidden
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.False);
+            // B should be seen by A because
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // brute force interest management
+        // => forceHidden should still work
+        [Test]
+        public override void ForceShown_Initial()
+        {
+            // A and B are too far from each other
+            identityB.transform.position = Vector3.right * (aoi.visRange + 1);
+
+            // force show A
+            identityA.visible = Visibility.ForceShown;
+
+            // rebuild for both
+            // initial rebuild while both are within range
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // A should see B because A is force shown
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            // B should not be seen by A because they are too far from each other
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.False);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void InRange_Initial()
+        {
+            // A and B are at (0,0,0) so within range!
+
+            // rebuild for both
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // both should see each other because they are in range
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void InRange_NotInitial()
+        {
+            // A and B are at (0,0,0) so within range!
+
+            // rebuild for both
+            NetworkServer.RebuildObservers(identityA, false);
+            NetworkServer.RebuildObservers(identityB, false);
+
+            // both should see each other because they are in range
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void OutOfRange_Initial()
+        {
+            // A and B are too far from each other
+            identityB.transform.position = Vector3.right * (aoi.visRange + 1);
+
+            // rebuild for boths
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // both should not see each other
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.False);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.False);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void OutOfRange_NotInitial()
+        {
+            // A and B are too far from each other
+            identityB.transform.position = Vector3.right * (aoi.visRange + 1);
+
+            // rebuild for boths
+            NetworkServer.RebuildObservers(identityA, false);
+            NetworkServer.RebuildObservers(identityB, false);
+
+            // both should not see each other
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.False);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.False);
+        }
+
+        // TODO add tests to make sure old observers are removed etc.
+    }
+}

Assets/Mirror/Tests/Editor/InterestManagementTests_Distance.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: ffb9dc0ff01e4f979c216984d7fc48d0
+timeCreated: 1613049838

Assets/Mirror/Tests/Editor/InterestManagementTests_SpatialHashing.cs

@@ -0,0 +1,154 @@
+// default = no component = everyone sees everyone
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public class InterestManagementTests_SpatialHashing : InterestManagementTests_Common
+    {
+        SpatialHashingInterestManagement aoi;
+
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+
+            // create spatial hashing object & component
+            CreateGameObject(out GameObject go, out aoi);
+            aoi.visRange = 10;
+            // setup server aoi since InterestManagement Awake isn't called
+            NetworkServer.aoi = aoi;
+
+            // rebuild grid once so the two connections are in there
+            aoi.Update();
+        }
+
+        [TearDown]
+        public override void TearDown()
+        {
+            base.TearDown();
+            // clear server aoi again
+            NetworkServer.aoi = null;
+        }
+
+        // brute force interest management
+        // => forceHidden should still work
+        [Test]
+        public override void ForceHidden_Initial()
+        {
+            // A and B are at (0,0,0) so within range!
+
+            // force hide A
+            identityA.visible = Visibility.ForceHidden;
+
+            // rebuild for both
+            // initial rebuild while both are within range
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // A should not be seen by B because A is force hidden
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.False);
+            // B should be seen by A because
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // brute force interest management
+        // => forceShown should still work
+        [Test]
+        public override void ForceShown_Initial()
+        {
+            // A and B are too far from each other
+            identityB.transform.position = Vector3.right * (aoi.visRange + 1);
+
+            // force show A
+            identityA.visible = Visibility.ForceShown;
+
+            // update grid now that positions were changed
+            aoi.Update();
+
+            // rebuild for both
+            // initial rebuild while both are within range
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // A should see B because A is force shown
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            // B should not be seen by A because they are too far from each other
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.False);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void InRange_Initial()
+        {
+            // A and B are at (0,0,0) so within range!
+
+            // rebuild for both
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // both should see each other because they are in range
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void InRange_NotInitial()
+        {
+            // A and B are at (0,0,0) so within range!
+
+            // rebuild for both
+            NetworkServer.RebuildObservers(identityA, false);
+            NetworkServer.RebuildObservers(identityB, false);
+
+            // both should see each other because they are in range
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.True);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.True);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void OutOfRange_Initial()
+        {
+            // A and B are too far from each other
+            identityB.transform.position = Vector3.right * (aoi.visRange + 1);
+
+            // update grid now that positions were changed
+            aoi.Update();
+
+            // rebuild for boths
+            NetworkServer.RebuildObservers(identityA, true);
+            NetworkServer.RebuildObservers(identityB, true);
+
+            // both should not see each other
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.False);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.False);
+        }
+
+        // brute force interest management
+        // => everyone should see everyone if in range
+        [Test]
+        public void OutOfRange_NotInitial()
+        {
+            // A and B are too far from each other
+            identityB.transform.position = Vector3.right * (aoi.visRange + 1);
+
+            // update grid now that positions were changed
+            aoi.Update();
+
+            // rebuild for boths
+            NetworkServer.RebuildObservers(identityA, false);
+            NetworkServer.RebuildObservers(identityB, false);
+
+            // both should not see each other
+            Assert.That(identityA.observers.ContainsKey(connectionB.connectionId), Is.False);
+            Assert.That(identityB.observers.ContainsKey(connectionA.connectionId), Is.False);
+        }
+
+        // TODO add tests to make sure old observers are removed etc.
+    }
+}

Assets/Mirror/Tests/Editor/InterestManagementTests_SpatialHashing.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 63d9e0d6aa9a4eec8b4e2db07e6261bf
+timeCreated: 1613117841

Assets/Mirror/Tests/Editor/LocalConnectionTest.cs

@@ -0,0 +1,71 @@
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public class LocalConnectionTest : MirrorTest
+    {
+        struct TestMessage : NetworkMessage {}
+
+        LocalConnectionToClient connectionToClient;
+        LocalConnectionToServer connectionToServer;
+
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+
+            CreateLocalConnectionPair(out connectionToClient, out connectionToServer);
+
+            // set up server/client connections so message handling works
+            NetworkClient.connection = connectionToServer;
+            NetworkServer.connections[connectionToClient.connectionId] = connectionToClient;
+        }
+
+        [TearDown]
+        public override void TearDown()
+        {
+            connectionToServer.Disconnect();
+            base.TearDown();
+        }
+
+        [Test]
+        public void ClientToServerTest()
+        {
+            Assert.That(connectionToClient.address, Is.EqualTo("localhost"));
+
+            bool invoked = false;
+            void Handler(NetworkConnection conn, TestMessage message)
+            {
+                invoked = true;
+            }
+
+            // set up handler on the server connection
+            NetworkServer.RegisterHandler<TestMessage>(Handler, false);
+
+            connectionToServer.Send(new TestMessage());
+            connectionToServer.Update();
+
+            Assert.True(invoked, "handler should have been invoked");
+        }
+
+        [Test]
+        public void ServerToClient()
+        {
+            Assert.That(connectionToServer.address, Is.EqualTo("localhost"));
+
+            bool invoked = false;
+            void Handler(TestMessage message)
+            {
+                invoked = true;
+            }
+
+            // set up handler on the client connection
+            NetworkClient.RegisterHandler<TestMessage>(Handler, false);
+
+            connectionToClient.Send(new TestMessage());
+            connectionToServer.Update();
+
+            Assert.True(invoked, "handler should have been invoked");
+        }
+    }
+}

Assets/Mirror/Tests/Editor/LocalConnectionTest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 405841e2a21c64d7585d5c71d06ffff2
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/MessageInheritanceTest.cs

@@ -0,0 +1,125 @@
+// TODO Send only supports structs. Consider removing those tests.
+using NUnit.Framework;
+
+namespace Mirror.Tests.MessageTests
+{
+    class ParentMessage : NetworkMessage
+    {
+        public int parentValue;
+    }
+
+    class ChildMessage : ParentMessage
+    {
+        public int childValue;
+    }
+
+
+    public abstract class RequestMessageBase : NetworkMessage
+    {
+        public int responseId = 0;
+    }
+    public class ResponseMessage : RequestMessageBase
+    {
+        public int state;
+        public string message = "";
+        public int errorCode = 0; // optional for error codes
+    }
+
+    //reverseOrder to test this https://github.com/vis2k/Mirror/issues/1925
+    public class ResponseMessageReverse : RequestMessageBaseReverse
+    {
+        public int state;
+        public string message = "";
+        public int errorCode = 0; // optional for error codes
+    }
+    public abstract class RequestMessageBaseReverse : NetworkMessage
+    {
+        public int responseId = 0;
+    }
+
+    [TestFixture]
+    public class MessageInheritanceTest
+    {
+        [Test]
+        public void SendsVauesInParentAndChildClass()
+        {
+            NetworkWriter writer = new NetworkWriter();
+
+            writer.Write(new ChildMessage
+            {
+                parentValue = 3,
+                childValue = 4
+            });
+
+            byte[] arr = writer.ToArray();
+
+            NetworkReader reader = new NetworkReader(arr);
+            ChildMessage received = reader.Read<ChildMessage>();
+
+            Assert.AreEqual(3, received.parentValue);
+            Assert.AreEqual(4, received.childValue);
+
+            int writeLength = writer.Position;
+            int readLength = reader.Position;
+            Assert.That(writeLength == readLength, $"OnSerializeAll and OnDeserializeAll calls write the same amount of data\n    writeLength={writeLength}\n    readLength={readLength}");
+        }
+
+        [Test]
+        public void SendsVauesWhenUsingAbstractClass()
+        {
+            NetworkWriter writer = new NetworkWriter();
+
+            const int state = 2;
+            const string message = "hello world";
+            const int responseId = 5;
+            writer.Write(new ResponseMessage
+            {
+                state = state,
+                message = message,
+                responseId = responseId,
+            });
+
+            byte[] arr = writer.ToArray();
+
+            NetworkReader reader = new NetworkReader(arr);
+            ResponseMessage received = reader.Read<ResponseMessage>();
+
+            Assert.AreEqual(state, received.state);
+            Assert.AreEqual(message, received.message);
+            Assert.AreEqual(responseId, received.responseId);
+
+            int writeLength = writer.Position;
+            int readLength = reader.Position;
+            Assert.That(writeLength == readLength, $"OnSerializeAll and OnDeserializeAll calls write the same amount of data\n    writeLength={writeLength}\n    readLength={readLength}");
+        }
+
+        [Test]
+        public void SendsVauesWhenUsingAbstractClassReverseDefineOrder()
+        {
+            NetworkWriter writer = new NetworkWriter();
+
+            const int state = 2;
+            const string message = "hello world";
+            const int responseId = 5;
+            writer.Write(new ResponseMessageReverse
+            {
+                state = state,
+                message = message,
+                responseId = responseId,
+            });
+
+            byte[] arr = writer.ToArray();
+
+            NetworkReader reader = new NetworkReader(arr);
+            ResponseMessageReverse received = reader.Read<ResponseMessageReverse>();
+
+            Assert.AreEqual(state, received.state);
+            Assert.AreEqual(message, received.message);
+            Assert.AreEqual(responseId, received.responseId);
+
+            int writeLength = writer.Position;
+            int readLength = reader.Position;
+            Assert.That(writeLength == readLength, $"OnSerializeAll and OnDeserializeAll calls write the same amount of data\n    writeLength={writeLength}\n    readLength={readLength}");
+        }
+    }
+}

Assets/Mirror/Tests/Editor/MessageInheritanceTest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 808855b645f9843d2b3077ab1304b2b3
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/MessagePackingTest.cs

@@ -0,0 +1,143 @@
+using System;
+using Mirror.Tests.MessageTests;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    [TestFixture]
+    public class MessagePackingTest
+    {
+        public struct EmptyMessage : NetworkMessage {}
+
+        // helper function to pack message into a simple byte[]
+        public static byte[] PackToByteArray<T>(T message)
+            where T : struct, NetworkMessage
+        {
+            using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
+            {
+                MessagePacking.Pack(message, writer);
+                return writer.ToArray();
+            }
+        }
+
+        // unpack a message we received
+        public static T UnpackFromByteArray<T>(byte[] data)
+            where T : struct, NetworkMessage
+        {
+            using (PooledNetworkReader networkReader = NetworkReaderPool.GetReader(data))
+            {
+                int msgType = MessagePacking.GetId<T>();
+
+                int id = networkReader.ReadUShort();
+                if (id != msgType)
+                    throw new FormatException($"Invalid message,  could not unpack {typeof(T).FullName}");
+
+                return networkReader.Read<T>();
+            }
+        }
+
+        // message id is generated from message.FullName.
+        // should be consistent across all platforms.
+        [Test]
+        public void GetId()
+        {
+            // "Mirror.Tests.MessageTests.TestMessage"
+            Debug.Log(typeof(TestMessage).FullName);
+            Assert.That(MessagePacking.GetId<TestMessage>(), Is.EqualTo(0x8706));
+        }
+
+        [Test]
+        public void TestPacking()
+        {
+            SceneMessage message = new SceneMessage()
+            {
+                sceneName = "Hello world",
+                sceneOperation = SceneOperation.LoadAdditive
+            };
+
+            byte[] data = PackToByteArray(message);
+
+            SceneMessage unpacked = UnpackFromByteArray<SceneMessage>(data);
+
+            Assert.That(unpacked.sceneName, Is.EqualTo("Hello world"));
+            Assert.That(unpacked.sceneOperation, Is.EqualTo(SceneOperation.LoadAdditive));
+        }
+
+        [Test]
+        public void UnpackWrongMessage()
+        {
+            SpawnMessage message = new SpawnMessage();
+
+            byte[] data = PackToByteArray(message);
+
+            Assert.Throws<FormatException>(() =>
+            {
+                ReadyMessage unpacked = UnpackFromByteArray<ReadyMessage>(data);
+            });
+        }
+
+        [Test]
+        public void TestUnpackIdMismatch()
+        {
+            // Unpack<T> has a id != msgType case that throws a FormatException.
+            // let's try to trigger it.
+
+            SceneMessage message = new SceneMessage()
+            {
+                sceneName = "Hello world",
+                sceneOperation = SceneOperation.LoadAdditive
+            };
+
+            byte[] data = PackToByteArray(message);
+
+            // overwrite the id
+            data[0] = 0x01;
+            data[1] = 0x02;
+
+            Assert.Throws<FormatException>(() =>
+            {
+                SceneMessage unpacked = UnpackFromByteArray<SceneMessage>(data);
+            });
+        }
+
+        [Test]
+        public void TestUnpackMessageNonGeneric()
+        {
+            // try a regular message
+            SceneMessage message = new SceneMessage()
+            {
+                sceneName = "Hello world",
+                sceneOperation = SceneOperation.LoadAdditive
+            };
+
+            byte[] data = PackToByteArray(message);
+            NetworkReader reader = new NetworkReader(data);
+
+            bool result = MessagePacking.Unpack(reader, out ushort msgType);
+            Assert.That(result, Is.EqualTo(true));
+            Assert.That(msgType, Is.EqualTo(BitConverter.ToUInt16(data, 0)));
+        }
+
+        [Test]
+        public void UnpackInvalidMessage()
+        {
+            // try an invalid message
+            NetworkReader reader2 = new NetworkReader(new byte[0]);
+            bool result2 = MessagePacking.Unpack(reader2, out ushort msgType2);
+            Assert.That(result2, Is.EqualTo(false));
+            Assert.That(msgType2, Is.EqualTo(0));
+        }
+
+        [Test]
+        public void MessageIdIsCorrectLength()
+        {
+            NetworkWriter writer = new NetworkWriter();
+            MessagePacking.Pack(new EmptyMessage(), writer);
+
+            ArraySegment<byte> segment = writer.ToArraySegment();
+
+            Assert.That(segment.Count, Is.EqualTo(MessagePacking.HeaderSize), "Empty message should have same size as HeaderSize");
+        }
+    }
+}

Assets/Mirror/Tests/Editor/MessagePackingTest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 8d57c17d9ee7c49e6bacc54ddbeac751
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/MiddlewareTransportTest.cs

@@ -0,0 +1,386 @@
+using System;
+using System.IO;
+using NSubstitute;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    public class MyMiddleware : MiddlewareTransport {}
+
+    [Description("Test to make sure inner methods are called when using Middleware Transport")]
+    public class MiddlewareTransportTest
+    {
+        Transport inner;
+        MyMiddleware middleware;
+
+        [SetUp]
+        public void Setup()
+        {
+            inner = Substitute.For<Transport>();
+
+            GameObject gameObject = new GameObject();
+
+            middleware = gameObject.AddComponent<MyMiddleware>();
+            middleware.inner = inner;
+        }
+
+        [TearDown]
+        public void TearDown()
+        {
+            GameObject.DestroyImmediate(middleware.gameObject);
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void TestAvailable(bool available)
+        {
+            inner.Available().Returns(available);
+
+            Assert.That(middleware.Available(), Is.EqualTo(available));
+
+            inner.Received(1).Available();
+        }
+
+        [Test]
+        [TestCase(Channels.Reliable, 4000)]
+        [TestCase(Channels.Reliable, 2000)]
+        [TestCase(Channels.Unreliable, 4000)]
+        public void TestGetMaxPacketSize(int channel, int packageSize)
+        {
+            inner.GetMaxPacketSize(Arg.Any<int>()).Returns(packageSize);
+
+            Assert.That(middleware.GetMaxPacketSize(channel), Is.EqualTo(packageSize));
+
+            inner.Received(1).GetMaxPacketSize(Arg.Is<int>(x => x == channel));
+            inner.Received(0).GetMaxPacketSize(Arg.Is<int>(x => x != channel));
+        }
+
+        [Test]
+        public void TestShutdown()
+        {
+            middleware.Shutdown();
+
+            inner.Received(1).Shutdown();
+        }
+
+        [Test]
+        [TestCase("localhost")]
+        [TestCase("example.com")]
+        public void TestClientConnect(string address)
+        {
+            middleware.ClientConnect(address);
+
+            inner.Received(1).ClientConnect(address);
+            inner.Received(0).ClientConnect(Arg.Is<string>(x => x != address));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void TestClientConnected(bool connected)
+        {
+            inner.ClientConnected().Returns(connected);
+
+            Assert.That(middleware.ClientConnected(), Is.EqualTo(connected));
+
+            inner.Received(1).ClientConnected();
+        }
+
+        [Test]
+        public void TestClientDisconnect()
+        {
+            middleware.ClientDisconnect();
+
+            inner.Received(1).ClientDisconnect();
+        }
+
+        [Test]
+        [TestCase(Channels.Reliable)]
+        [TestCase(Channels.Unreliable)]
+        public void TestClientSend(int channel)
+        {
+            byte[] array = new byte[10];
+            const int offset = 2;
+            const int count = 5;
+            ArraySegment<byte> segment = new ArraySegment<byte>(array, offset, count);
+
+            middleware.ClientSend(segment, channel);
+
+            inner.Received(1).ClientSend(Arg.Is<ArraySegment<byte>>(x => x.Array == array && x.Offset == offset && x.Count == count), channel);
+            inner.Received(0).ClientSend(Arg.Any<ArraySegment<byte>>(), Arg.Is<int>(x => x != channel));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void TestServerActive(bool active)
+        {
+            inner.ServerActive().Returns(active);
+
+            Assert.That(middleware.ServerActive(), Is.EqualTo(active));
+
+            inner.Received(1).ServerActive();
+        }
+
+        [Test]
+        public void TestServerStart()
+        {
+            middleware.ServerStart();
+
+            inner.Received(1).ServerStart();
+        }
+
+        [Test]
+        public void TestServerStop()
+        {
+            middleware.ServerStop();
+
+            inner.Received(1).ServerStop();
+        }
+
+        [Test]
+        [TestCase(0, 0)]
+        [TestCase(1, 0)]
+        [TestCase(0, 1)]
+        [TestCase(19, 1)]
+        public void TestServerSend(int id, int channel)
+        {
+            byte[] array = new byte[10];
+            const int offset = 2;
+            const int count = 5;
+            ArraySegment<byte> segment = new ArraySegment<byte>(array, offset, count);
+
+            middleware.ServerSend(id, segment, channel);
+
+            inner.Received(1).ServerSend(id, Arg.Is<ArraySegment<byte>>(x => x.Array == array && x.Offset == offset && x.Count == count), channel);
+            // only need to check first arg,
+            inner.Received(0).ServerSend(Arg.Is<int>(x => x != id), Arg.Any<ArraySegment<byte>>(), Arg.Any<int>());
+        }
+
+        [Test]
+        [TestCase(0, "tcp4://localhost:7777")]
+        [TestCase(19, "tcp4://example.com:7777")]
+        public void TestServerGetClientAddress(int id, string result)
+        {
+            inner.ServerGetClientAddress(id).Returns(result);
+
+            Assert.That(middleware.ServerGetClientAddress(id), Is.EqualTo(result));
+
+            inner.Received(1).ServerGetClientAddress(id);
+            inner.Received(0).ServerGetClientAddress(Arg.Is<int>(x => x != id));
+
+        }
+
+        [Test]
+        [TestCase("tcp4://localhost:7777")]
+        [TestCase("tcp4://example.com:7777")]
+        public void TestServerUri(string address)
+        {
+            Uri uri = new Uri(address);
+            inner.ServerUri().Returns(uri);
+
+            Assert.That(middleware.ServerUri(), Is.EqualTo(uri));
+
+            inner.Received(1).ServerUri();
+        }
+
+        [Test]
+        public void TestClientConnectedCallback()
+        {
+            int called = 0;
+            middleware.OnClientConnected = () =>
+            {
+                called++;
+            };
+            // connect to give callback to inner
+            middleware.ClientConnect("localhost");
+
+            inner.OnClientConnected.Invoke();
+            Assert.That(called, Is.EqualTo(1));
+
+            inner.OnClientConnected.Invoke();
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(1)]
+        public void TestClientDataReceivedCallback(int channel)
+        {
+            byte[] data = new byte[4];
+            ArraySegment<byte> segment = new ArraySegment<byte>(data, 1, 2);
+
+            int called = 0;
+            middleware.OnClientDataReceived = (d, c) =>
+            {
+                called++;
+                Assert.That(c, Is.EqualTo(channel));
+                Assert.That(d.Array, Is.EqualTo(segment.Array));
+                Assert.That(d.Offset, Is.EqualTo(segment.Offset));
+                Assert.That(d.Count, Is.EqualTo(segment.Count));
+            };
+            // connect to give callback to inner
+            middleware.ClientConnect("localhost");
+
+            inner.OnClientDataReceived.Invoke(segment, channel);
+            Assert.That(called, Is.EqualTo(1));
+
+
+            data = new byte[4];
+            segment = new ArraySegment<byte>(data, 0, 3);
+
+            inner.OnClientDataReceived.Invoke(segment, channel);
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        [Test]
+        public void TestClientDisconnectedCallback()
+        {
+            int called = 0;
+            middleware.OnClientDisconnected = () =>
+            {
+                called++;
+            };
+            // connect to give callback to inner
+            middleware.ClientConnect("localhost");
+
+            inner.OnClientDisconnected.Invoke();
+            Assert.That(called, Is.EqualTo(1));
+
+            inner.OnClientDisconnected.Invoke();
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        [Test]
+        public void TestClientErrorCallback()
+        {
+            Exception exception = new InvalidDataException();
+
+            int called = 0;
+            middleware.OnClientError = (e) =>
+            {
+                called++;
+                Assert.That(e, Is.EqualTo(exception));
+            };
+            // connect to give callback to inner
+            middleware.ClientConnect("localhost");
+
+            inner.OnClientError.Invoke(exception);
+            Assert.That(called, Is.EqualTo(1));
+
+            exception = new NullReferenceException();
+
+            inner.OnClientError.Invoke(exception);
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(1)]
+        [TestCase(19)]
+        public void TestServerConnectedCallback(int id)
+        {
+            int called = 0;
+            middleware.OnServerConnected = (i) =>
+            {
+                called++;
+                Assert.That(i, Is.EqualTo(id));
+            };
+            // start to give callback to inner
+            middleware.ServerStart();
+
+            inner.OnServerConnected.Invoke(id);
+            Assert.That(called, Is.EqualTo(1));
+
+            inner.OnServerConnected.Invoke(id);
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        [Test]
+        [TestCase(0, 0)]
+        [TestCase(1, 0)]
+        [TestCase(19, 0)]
+        [TestCase(0, 1)]
+        [TestCase(1, 1)]
+        [TestCase(19, 1)]
+        public void TestServerDataReceivedCallback(int id, int channel)
+        {
+            byte[] data = new byte[4];
+            ArraySegment<byte> segment = new ArraySegment<byte>(data, 1, 2);
+
+            int called = 0;
+            middleware.OnServerDataReceived = (i, d, c) =>
+            {
+                called++;
+                Assert.That(i, Is.EqualTo(id));
+                Assert.That(c, Is.EqualTo(channel));
+                Assert.That(d.Array, Is.EqualTo(segment.Array));
+                Assert.That(d.Offset, Is.EqualTo(segment.Offset));
+                Assert.That(d.Count, Is.EqualTo(segment.Count));
+            };
+            // start to give callback to inner
+            middleware.ServerStart();
+
+            inner.OnServerDataReceived.Invoke(id, segment, channel);
+            Assert.That(called, Is.EqualTo(1));
+
+
+            data = new byte[4];
+            segment = new ArraySegment<byte>(data, 0, 3);
+
+            inner.OnServerDataReceived.Invoke(id, segment, channel);
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(1)]
+        [TestCase(19)]
+        public void TestServerDisconnectedCallback(int id)
+        {
+            int called = 0;
+            middleware.OnServerDisconnected = (i) =>
+            {
+                called++;
+                Assert.That(i, Is.EqualTo(id));
+            };
+            // start to give callback to inner
+            middleware.ServerStart();
+
+            inner.OnServerDisconnected.Invoke(id);
+            Assert.That(called, Is.EqualTo(1));
+
+            inner.OnServerDisconnected.Invoke(id);
+            Assert.That(called, Is.EqualTo(2));
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(1)]
+        [TestCase(19)]
+        public void TestServerErrorCallback(int id)
+        {
+            Exception exception = new InvalidDataException();
+
+            int called = 0;
+            middleware.OnServerError = (i, e) =>
+            {
+                called++;
+                Assert.That(i, Is.EqualTo(id));
+                Assert.That(e, Is.EqualTo(exception));
+            };
+            // start to give callback to inner
+            middleware.ServerStart();
+
+            inner.OnServerError.Invoke(id, exception);
+            Assert.That(called, Is.EqualTo(1));
+
+            exception = new NullReferenceException();
+
+            inner.OnServerError.Invoke(id, exception);
+            Assert.That(called, Is.EqualTo(2));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/MiddlewareTransportTest.cs.meta

@@ -0,0 +1,11 @@
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+guid: 1ee4c7efa89013a41aeee942e60af4e7
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
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Assets/Mirror/Tests/Editor/Mirror.Tests.asmdef

@@ -0,0 +1,34 @@
+{
+    "name": "Mirror.Tests",
+    "rootNamespace": "",
+    "references": [
+        "Mirror",
+        "Mirror.Editor",
+        "Mirror.Components",
+        "Mirror.Tests.Common",
+        "Telepathy",
+        "UnityEngine.TestRunner",
+        "UnityEditor.TestRunner",
+        "Unity.Mirror.CodeGen",
+        "WeaverTestExtraAssembly"
+    ],
+    "includePlatforms": [
+        "Editor"
+    ],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": true,
+    "precompiledReferences": [
+        "NSubstitute.dll",
+        "Castle.Core.dll",
+        "System.Threading.Tasks.Extensions.dll",
+        "Mono.CecilX.dll",
+        "nunit.framework.dll"
+    ],
+    "autoReferenced": false,
+    "defineConstraints": [
+        "UNITY_INCLUDE_TESTS"
+    ],
+    "versionDefines": [],
+    "noEngineReferences": false
+}

Assets/Mirror/Tests/Editor/Mirror.Tests.asmdef.meta

@@ -0,0 +1,7 @@
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+guid: 8b489029f75e64a7bbf6918bf1a49e39
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+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/MultiplexTest.cs

@@ -0,0 +1,180 @@
+using System;
+using NSubstitute;
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public class MultiplexTest : MirrorTest
+    {
+        Transport transport1;
+        Transport transport2;
+        new MultiplexTransport transport;
+
+        [SetUp]
+        public void Setup()
+        {
+            base.SetUp();
+
+            CreateGameObject(out _, out transport);
+
+            transport1 = Substitute.For<Transport>();
+            transport2 = Substitute.For<Transport>();
+            transport.transports = new[] { transport1, transport2 };
+
+            transport.Awake();
+        }
+
+        // A Test behaves as an ordinary method
+        [Test]
+        public void TestAvailable()
+        {
+            transport1.Available().Returns(true);
+            transport2.Available().Returns(false);
+            Assert.That(transport.Available());
+        }
+
+        // A Test behaves as an ordinary method
+        [Test]
+        public void TestNotAvailable()
+        {
+            transport1.Available().Returns(false);
+            transport2.Available().Returns(false);
+            Assert.That(transport.Available(), Is.False);
+        }
+
+        // A Test behaves as an ordinary method
+        [Test]
+        public void TestConnect()
+        {
+            transport1.Available().Returns(false);
+            transport2.Available().Returns(true);
+            transport.ClientConnect("some.server.com");
+
+            transport1.DidNotReceive().ClientConnect(Arg.Any<string>());
+            transport2.Received().ClientConnect("some.server.com");
+        }
+
+        // A Test behaves as an ordinary method
+        [Test]
+        public void TestConnectFirstUri()
+        {
+            Uri uri = new Uri("tcp://some.server.com");
+
+            transport1.Available().Returns(true);
+            transport2.Available().Returns(true);
+
+            transport.ClientConnect(uri);
+            transport1.Received().ClientConnect(uri);
+            transport2.DidNotReceive().ClientConnect(uri);
+        }
+
+
+        // A Test behaves as an ordinary method
+        [Test]
+        public void TestConnectSecondUri()
+        {
+            Uri uri = new Uri("ws://some.server.com");
+
+            transport1.Available().Returns(true);
+
+            // first transport does not support websocket
+            transport1
+                .When(x => x.ClientConnect(uri))
+                .Do(x => { throw new ArgumentException("Scheme not supported"); });
+
+            transport2.Available().Returns(true);
+
+            transport.ClientConnect(uri);
+            transport2.Received().ClientConnect(uri);
+        }
+
+        [Test]
+        public void TestConnected()
+        {
+            transport1.Available().Returns(true);
+            transport.ClientConnect("some.server.com");
+
+            transport1.ClientConnected().Returns(true);
+
+            Assert.That(transport.ClientConnected());
+        }
+
+        [Test]
+        public void TestDisconnect()
+        {
+            transport1.Available().Returns(true);
+            transport.ClientConnect("some.server.com");
+
+            transport.ClientDisconnect();
+
+            transport1.Received().ClientDisconnect();
+        }
+
+        [Test]
+        public void TestClientSend()
+        {
+            transport1.Available().Returns(true);
+            transport.ClientConnect("some.server.com");
+
+            byte[] data = { 1, 2, 3 };
+            ArraySegment<byte> segment = new ArraySegment<byte>(data);
+
+            transport.ClientSend(segment, 3);
+
+            transport1.Received().ClientSend(segment, 3);
+        }
+
+        [Test]
+        public void TestClient1Connected()
+        {
+            transport1.Available().Returns(true);
+            transport2.Available().Returns(true);
+
+            Action callback = Substitute.For<Action>();
+            // find available
+            transport.Awake();
+            // set event and connect to give event to inner
+            transport.OnClientConnected = callback;
+            transport.ClientConnect("localhost");
+            transport1.OnClientConnected.Invoke();
+            callback.Received().Invoke();
+        }
+
+        [Test]
+        public void TestClient2Connected()
+        {
+            transport1.Available().Returns(false);
+            transport2.Available().Returns(true);
+
+            Action callback = Substitute.For<Action>();
+            // find available
+            transport.Awake();
+            // set event and connect to give event to inner
+            transport.OnClientConnected = callback;
+            transport.ClientConnect("localhost");
+            transport2.OnClientConnected.Invoke();
+            callback.Received().Invoke();
+        }
+
+        [Test]
+        public void TestServerConnected()
+        {
+            byte[] data = { 1, 2, 3 };
+            ArraySegment<byte> segment = new ArraySegment<byte>(data);
+
+            // on connect, send a message back
+            void SendMessage(int connectionId)
+            {
+                transport.ServerSend(connectionId, segment, 5);
+            }
+
+            // set event and Start to give event to inner
+            transport.OnServerConnected = SendMessage;
+            transport.ServerStart();
+
+            transport1.OnServerConnected.Invoke(1);
+
+            transport1.Received().ServerSend(1, segment, 5);
+        }
+    }
+}

Assets/Mirror/Tests/Editor/MultiplexTest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: f0d8bef6afd464247bf433cdc5d3ff23
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/NetworkBehaviourDirtyBitsTests.cs

@@ -0,0 +1,184 @@
+// dirty bits are powerful magic.
+// add some tests to guarantee correct behaviour.
+using NUnit.Framework;
+using UnityEngine;
+
+namespace Mirror.Tests
+{
+    class NetworkBehaviourWithSyncVarsAndCollections : NetworkBehaviour
+    {
+        // SyncVars
+        [SyncVar] public int health;
+        [SyncVar] public int mana;
+
+        // SyncCollections
+        public readonly SyncList<int> list = new SyncList<int>();
+        public readonly SyncDictionary<int, string> dict = new SyncDictionary<int, string>();
+    }
+
+    public class NetworkBehaviourSyncVarDirtyBitsExposed : NetworkBehaviour
+    {
+        public ulong syncVarDirtyBitsExposed => syncVarDirtyBits;
+    }
+
+    public class NetworkBehaviourDirtyBitsTests : MirrorEditModeTest
+    {
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+
+            // SyncLists are only set dirty while owner has observers.
+            // need a connection.
+            NetworkServer.Listen(1);
+            ConnectHostClientBlockingAuthenticatedAndReady();
+        }
+
+        [Test]
+        public void SetSyncVarDirtyBit()
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out NetworkBehaviourSyncVarDirtyBitsExposed comp);
+
+            // set 3rd dirty bit.
+            comp.SetSyncVarDirtyBit(0b_00000000_00000100);
+            Assert.That(comp.syncVarDirtyBitsExposed, Is.EqualTo(0b_00000000_00000100));
+
+            // set 5th dirty bit.
+            // both 3rd and 5th should be set.
+            comp.SetSyncVarDirtyBit(0b_00000000_00010000);
+            Assert.That(comp.syncVarDirtyBitsExposed, Is.EqualTo(0b_00000000_00010100));
+        }
+
+        // changing a SyncObject (collection) should modify the dirty mask.
+        [Test]
+        public void SyncObjectsSetDirtyBits()
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out NetworkBehaviourWithSyncVarsAndCollections comp);
+
+            // not dirty by default
+            Assert.That(comp.syncObjectDirtyBits, Is.EqualTo(0UL));
+
+            // change the list. should be dirty now.
+            comp.list.Add(42);
+            Assert.That(comp.syncObjectDirtyBits, Is.EqualTo(0b01));
+
+            // change the dict. should both be dirty.
+            comp.dict[42] = null;
+            Assert.That(comp.syncObjectDirtyBits, Is.EqualTo(0b11));
+        }
+
+        [Test]
+        public void IsDirty()
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity identity, out NetworkBehaviourWithSyncVarsAndCollections comp);
+
+            // not dirty by default
+            Assert.That(comp.IsDirty(), Is.False);
+
+            // changing a [SyncVar] should set it dirty
+            ++comp.health;
+            Assert.That(comp.IsDirty(), Is.True);
+            comp.ClearAllDirtyBits();
+
+            // changing a SyncCollection should set it dirty
+            comp.list.Add(42);
+            Assert.That(comp.IsDirty(), Is.True);
+            comp.ClearAllDirtyBits();
+
+            // it should only be dirty after syncInterval elapsed
+            comp.syncInterval = float.MaxValue;
+            Assert.That(comp.IsDirty(), Is.False);
+        }
+
+        [Test]
+        public void ClearAllDirtyBitsClearsSyncVarDirtyBits()
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out EmptyBehaviour emptyBehaviour);
+
+            // set syncinterval so dirtybit works fine
+            emptyBehaviour.syncInterval = 0;
+            Assert.That(emptyBehaviour.IsDirty(), Is.False);
+
+            // set one syncvar dirty bit
+            emptyBehaviour.SetSyncVarDirtyBit(1);
+            Assert.That(emptyBehaviour.IsDirty(), Is.True);
+
+            // clear it
+            emptyBehaviour.ClearAllDirtyBits();
+            Assert.That(emptyBehaviour.IsDirty(), Is.False);
+        }
+
+        [Test]
+        public void ClearAllDirtyBitsClearsSyncObjectsDirtyBits()
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out NetworkBehaviourWithSyncVarsAndCollections comp);
+
+            // set syncinterval so dirtybit works fine
+            comp.syncInterval = 0;
+            Assert.That(comp.IsDirty(), Is.False);
+
+            // dirty the synclist
+            comp.list.Add(42);
+            Assert.That(comp.IsDirty, Is.True);
+
+            // clear bits should clear synclist bits too
+            comp.ClearAllDirtyBits();
+            Assert.That(comp.IsDirty, Is.False);
+        }
+
+        // NetworkServer.Broadcast clears all dirty bits in all spawned
+        // identity's components if they have no observers.
+        //
+        // this way dirty bit tracking only starts after first observer.
+        // otherwise first observer would still get dirty update for everything
+        // that was dirty before he observed. even though he already got the
+        // full state in spawn packet.
+        [Test]
+        public void DirtyBitsAreClearedForSpawnedWithoutObservers()
+        {
+            // need one player, one monster
+            CreateNetworkedAndSpawnPlayer(out _, out NetworkIdentity player, NetworkServer.localConnection);
+            CreateNetworkedAndSpawn(out _, out NetworkIdentity monster, out NetworkBehaviourWithSyncVarsAndCollections monsterComp);
+
+            // without AOI, player connection sees everyone automatically.
+            // remove the monster from observing.
+            // remvoe player from monster observers.
+            monster.RemoveObserver(player.connectionToClient);
+            Assert.That(monster.observers.Count, Is.EqualTo(0));
+
+            // modify something in the monster so that dirty bit is set
+            monsterComp.syncInterval = 0;
+            ++monsterComp.health;
+            Assert.That(monsterComp.IsDirty(), Is.True);
+
+            // add first observer. dirty bits should be cleared.
+            monster.AddObserver(player.connectionToClient);
+            Assert.That(monsterComp.IsDirty(), Is.False);
+        }
+    }
+
+    // hook tests can only be ran when inheriting from NetworkBehaviour
+    public class NetworkBehaviourDirtyBitsHookGuardTester : NetworkBehaviour
+    {
+        [Test]
+        public void HookGuard()
+        {
+            // set hook guard for some bits
+            for (int i = 0; i < 10; ++i)
+            {
+                ulong bit = 1ul << i;
+
+                // should be false by default
+                Assert.That(GetSyncVarHookGuard(bit), Is.False);
+
+                // set true
+                SetSyncVarHookGuard(bit, true);
+                Assert.That(GetSyncVarHookGuard(bit), Is.True);
+
+                // set false again
+                SetSyncVarHookGuard(bit, false);
+                Assert.That(GetSyncVarHookGuard(bit), Is.False);
+            }
+        }
+    }
+}

Assets/Mirror/Tests/Editor/NetworkBehaviourDirtyBitsTests.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 71cd60f7177a4d3da75bb87f5ac13a18
+timeCreated: 1631772886

Assets/Mirror/Tests/Editor/NetworkBehaviourSerializeTest.cs

@@ -0,0 +1,341 @@
+using NUnit.Framework;
+using UnityEngine;
+
+// Note: Weaver doesn't run on nested class so use namespace to group classes instead
+namespace Mirror.Tests.NetworkBehaviourSerialize
+{
+    #region No OnSerialize/OnDeserialize override
+    abstract class AbstractBehaviour : NetworkBehaviour
+    {
+        public readonly SyncList<bool> syncListInAbstract = new SyncList<bool>();
+
+        [SyncVar]
+        public int SyncFieldInAbstract;
+    }
+
+    class BehaviourWithSyncVar : NetworkBehaviour
+    {
+        public readonly SyncList<bool> syncList = new SyncList<bool>();
+
+        [SyncVar]
+        public int SyncField;
+    }
+
+    class OverrideBehaviourFromSyncVar : AbstractBehaviour {}
+
+    class OverrideBehaviourWithSyncVarFromSyncVar : AbstractBehaviour
+    {
+        public readonly SyncList<bool> syncListInOverride = new SyncList<bool>();
+
+        [SyncVar]
+        public int SyncFieldInOverride;
+    }
+
+    class MiddleClass : AbstractBehaviour
+    {
+        // class with no sync var
+    }
+
+    class SubClass : MiddleClass
+    {
+        // class with sync var
+        // this is to make sure that override works correctly if base class doesn't have sync vars
+        [SyncVar]
+        public Vector3 anotherSyncField;
+    }
+
+    class MiddleClassWithSyncVar : AbstractBehaviour
+    {
+        // class with sync var
+        [SyncVar]
+        public string syncFieldInMiddle;
+    }
+
+    class SubClassFromSyncVar : MiddleClassWithSyncVar
+    {
+        // class with sync var
+        // this is to make sure that override works correctly if base class doesn't have sync vars
+        [SyncVar]
+        public Vector3 syncFieldInSub;
+    }
+    #endregion
+
+    #region OnSerialize/OnDeserialize override
+
+    class BehaviourWithSyncVarWithOnSerialize : NetworkBehaviour
+    {
+        public readonly SyncList<bool> syncList = new SyncList<bool>();
+
+        [SyncVar]
+        public int SyncField;
+
+        public float customSerializeField;
+
+        public override bool OnSerialize(NetworkWriter writer, bool initialState)
+        {
+            writer.WriteFloat(customSerializeField);
+            return base.OnSerialize(writer, initialState);
+        }
+        public override void OnDeserialize(NetworkReader reader, bool initialState)
+        {
+            customSerializeField = reader.ReadFloat();
+            base.OnDeserialize(reader, initialState);
+        }
+    }
+
+    class OverrideBehaviourFromSyncVarWithOnSerialize : AbstractBehaviour
+    {
+        public float customSerializeField;
+
+        public override bool OnSerialize(NetworkWriter writer, bool initialState)
+        {
+            writer.WriteFloat(customSerializeField);
+            return base.OnSerialize(writer, initialState);
+        }
+        public override void OnDeserialize(NetworkReader reader, bool initialState)
+        {
+            customSerializeField = reader.ReadFloat();
+            base.OnDeserialize(reader, initialState);
+        }
+    }
+
+    class OverrideBehaviourWithSyncVarFromSyncVarWithOnSerialize : AbstractBehaviour
+    {
+        public readonly SyncList<bool> syncListInOverride = new SyncList<bool>();
+
+        [SyncVar]
+        public int SyncFieldInOverride;
+
+        public float customSerializeField;
+
+        public override bool OnSerialize(NetworkWriter writer, bool initialState)
+        {
+            writer.WriteFloat(customSerializeField);
+            return base.OnSerialize(writer, initialState);
+        }
+        public override void OnDeserialize(NetworkReader reader, bool initialState)
+        {
+            customSerializeField = reader.ReadFloat();
+            base.OnDeserialize(reader, initialState);
+        }
+    }
+    #endregion
+
+    public class NetworkBehaviourSerializeTest : MirrorEditModeTest
+    {
+        static void SyncNetworkBehaviour(NetworkBehaviour source, NetworkBehaviour target, bool initialState)
+        {
+            using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
+            {
+                source.OnSerialize(writer, initialState);
+
+                using (PooledNetworkReader reader = NetworkReaderPool.GetReader(writer.ToArraySegment()))
+                {
+                    target.OnDeserialize(reader, initialState);
+                }
+            }
+        }
+
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+
+            // SyncLists are only set dirty while owner has observers.
+            // need a connection.
+            NetworkServer.Listen(1);
+            ConnectHostClientBlockingAuthenticatedAndReady();
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void BehaviourWithSyncVarTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out BehaviourWithSyncVar source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out BehaviourWithSyncVar target);
+
+            source.SyncField = 10;
+            source.syncList.Add(true);
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncField, Is.EqualTo(10));
+            Assert.That(target.syncList.Count, Is.EqualTo(1));
+            Assert.That(target.syncList[0], Is.True);
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void OverrideBehaviourFromSyncVarTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourFromSyncVar source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourFromSyncVar target);
+
+            source.SyncFieldInAbstract = 12;
+            source.syncListInAbstract.Add(true);
+            source.syncListInAbstract.Add(false);
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncFieldInAbstract, Is.EqualTo(12));
+            Assert.That(target.syncListInAbstract.Count, Is.EqualTo(2));
+            Assert.That(target.syncListInAbstract[0], Is.True);
+            Assert.That(target.syncListInAbstract[1], Is.False);
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void OverrideBehaviourWithSyncVarFromSyncVarTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourWithSyncVarFromSyncVar source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourWithSyncVarFromSyncVar target);
+
+            source.SyncFieldInAbstract = 10;
+            source.syncListInAbstract.Add(true);
+
+            source.SyncFieldInOverride = 52;
+            source.syncListInOverride.Add(false);
+            source.syncListInOverride.Add(true);
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncFieldInAbstract, Is.EqualTo(10));
+            Assert.That(target.syncListInAbstract.Count, Is.EqualTo(1));
+            Assert.That(target.syncListInAbstract[0], Is.True);
+
+
+            Assert.That(target.SyncFieldInOverride, Is.EqualTo(52));
+            Assert.That(target.syncListInOverride.Count, Is.EqualTo(2));
+            Assert.That(target.syncListInOverride[0], Is.False);
+            Assert.That(target.syncListInOverride[1], Is.True);
+        }
+
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void SubClassTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out SubClass source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out SubClass target);
+
+            source.SyncFieldInAbstract = 10;
+            source.syncListInAbstract.Add(true);
+
+            source.anotherSyncField = new Vector3(40, 20, 10);
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncFieldInAbstract, Is.EqualTo(10));
+            Assert.That(target.syncListInAbstract.Count, Is.EqualTo(1));
+            Assert.That(target.syncListInAbstract[0], Is.True);
+
+            Assert.That(target.anotherSyncField, Is.EqualTo(new Vector3(40, 20, 10)));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void SubClassFromSyncVarTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out SubClassFromSyncVar source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out SubClassFromSyncVar target);
+
+            source.SyncFieldInAbstract = 10;
+            source.syncListInAbstract.Add(true);
+
+            source.syncFieldInMiddle = "Hello World!";
+            source.syncFieldInSub = new Vector3(40, 20, 10);
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncFieldInAbstract, Is.EqualTo(10));
+            Assert.That(target.syncListInAbstract.Count, Is.EqualTo(1));
+            Assert.That(target.syncListInAbstract[0], Is.True);
+
+            Assert.That(target.syncFieldInMiddle, Is.EqualTo("Hello World!"));
+            Assert.That(target.syncFieldInSub, Is.EqualTo(new Vector3(40, 20, 10)));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void BehaviourWithSyncVarWithOnSerializeTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out BehaviourWithSyncVarWithOnSerialize source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out BehaviourWithSyncVarWithOnSerialize target);
+
+            source.SyncField = 10;
+            source.syncList.Add(true);
+
+            source.customSerializeField = 20.5f;
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncField, Is.EqualTo(10));
+            Assert.That(target.syncList.Count, Is.EqualTo(1));
+            Assert.That(target.syncList[0], Is.True);
+
+            Assert.That(target.customSerializeField, Is.EqualTo(20.5f));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void OverrideBehaviourFromSyncVarWithOnSerializeTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourFromSyncVarWithOnSerialize source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourFromSyncVarWithOnSerialize target);
+
+            source.SyncFieldInAbstract = 12;
+            source.syncListInAbstract.Add(true);
+            source.syncListInAbstract.Add(false);
+
+            source.customSerializeField = 20.5f;
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncFieldInAbstract, Is.EqualTo(12));
+            Assert.That(target.syncListInAbstract.Count, Is.EqualTo(2));
+            Assert.That(target.syncListInAbstract[0], Is.True);
+            Assert.That(target.syncListInAbstract[1], Is.False);
+
+            Assert.That(target.customSerializeField, Is.EqualTo(20.5f));
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void OverrideBehaviourWithSyncVarFromSyncVarWithOnSerializeTest(bool initialState)
+        {
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourWithSyncVarFromSyncVarWithOnSerialize source);
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out OverrideBehaviourWithSyncVarFromSyncVarWithOnSerialize target);
+
+            source.SyncFieldInAbstract = 10;
+            source.syncListInAbstract.Add(true);
+
+            source.SyncFieldInOverride = 52;
+            source.syncListInOverride.Add(false);
+            source.syncListInOverride.Add(true);
+
+            source.customSerializeField = 20.5f;
+
+            SyncNetworkBehaviour(source, target, initialState);
+
+            Assert.That(target.SyncFieldInAbstract, Is.EqualTo(10));
+            Assert.That(target.syncListInAbstract.Count, Is.EqualTo(1));
+            Assert.That(target.syncListInAbstract[0], Is.True);
+
+
+            Assert.That(target.SyncFieldInOverride, Is.EqualTo(52));
+            Assert.That(target.syncListInOverride.Count, Is.EqualTo(2));
+            Assert.That(target.syncListInOverride[0], Is.False);
+            Assert.That(target.syncListInOverride[1], Is.True);
+
+            Assert.That(target.customSerializeField, Is.EqualTo(20.5f));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/NetworkBehaviourSerializeTest.cs.meta

@@ -0,0 +1,11 @@
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+guid: 253d419ce2900134482c3c8b76883c60
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/NetworkBehaviourTests.cs

@@ -0,0 +1,884 @@
+using Mirror.RemoteCalls;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Mirror.Tests
+{
+    class EmptyBehaviour : NetworkBehaviour {}
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class NetworkBehaviourDelegateComponent : NetworkBehaviour
+    {
+        public static void Delegate(NetworkBehaviour comp, NetworkReader reader, NetworkConnection senderConnection) {}
+        public static void Delegate2(NetworkBehaviour comp, NetworkReader reader, NetworkConnection senderConnection) {}
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class NetworkBehaviourSetSyncVarGameObjectComponent : NetworkBehaviour
+    {
+        //[SyncVar]
+        public GameObject test;
+        // usually generated by weaver
+        public uint testNetId;
+
+        // SetSyncVarGameObject wrapper to expose it
+        public void SetSyncVarGameObjectExposed(GameObject newGameObject, ulong dirtyBit) =>
+            SetSyncVarGameObject(newGameObject, ref test, dirtyBit, ref testNetId);
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class NetworkBehaviourGetSyncVarGameObjectComponent : NetworkBehaviour
+    {
+        //[SyncVar]
+        public GameObject test;
+        // usually generated by weaver
+        public uint testNetId;
+
+        // SetSyncVarGameObject wrapper to expose it
+        public GameObject GetSyncVarGameObjectExposed() =>
+            GetSyncVarGameObject(testNetId, ref test);
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class NetworkBehaviourSetSyncVarNetworkIdentityComponent : NetworkBehaviour
+    {
+        //[SyncVar]
+        public NetworkIdentity test;
+        // usually generated by weaver
+        public uint testNetId;
+
+        // SetSyncVarNetworkIdentity wrapper to expose it
+        public void SetSyncVarNetworkIdentityExposed(NetworkIdentity newNetworkIdentity, ulong dirtyBit) =>
+            SetSyncVarNetworkIdentity(newNetworkIdentity, ref test, dirtyBit, ref testNetId);
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class NetworkBehaviourGetSyncVarNetworkIdentityComponent : NetworkBehaviour
+    {
+        //[SyncVar]
+        public NetworkIdentity test;
+        // usually generated by weaver
+        public uint testNetId;
+
+        // SetSyncVarNetworkIdentity wrapper to expose it
+        public NetworkIdentity GetSyncVarNetworkIdentityExposed() =>
+            GetSyncVarNetworkIdentity(testNetId, ref test);
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class OnStopClientComponent : NetworkBehaviour
+    {
+        public int called;
+        public override void OnStopClient() => ++called;
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class OnStartClientComponent : NetworkBehaviour
+    {
+        public int called;
+        public override void OnStartClient() => ++called;
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class OnStartLocalPlayerComponent : NetworkBehaviour
+    {
+        public int called;
+        public override void OnStartLocalPlayer() => ++called;
+    }
+
+    public class NetworkBehaviourTests : MirrorEditModeTest
+    {
+        [TearDown]
+        public override void TearDown()
+        {
+            NetworkServer.RemoveLocalConnection();
+            base.TearDown();
+        }
+
+        [Test]
+        public void IsServerOnly()
+        {
+            CreateNetworked(out _, out NetworkIdentity identity, out EmptyBehaviour emptyBehaviour);
+
+            // call OnStartServer so isServer is true
+            identity.OnStartServer();
+            Assert.That(identity.isServer, Is.True);
+
+            // isServerOnly should be true when isServer = true && isClient = false
+            Assert.That(emptyBehaviour.isServer, Is.True);
+            Assert.That(emptyBehaviour.isClient, Is.False);
+            Assert.That(emptyBehaviour.isServerOnly, Is.True);
+        }
+
+        [Test]
+        public void IsClientOnly()
+        {
+            CreateNetworked(out _, out NetworkIdentity identity, out EmptyBehaviour emptyBehaviour);
+
+            // isClientOnly should be true when isServer = false && isClient = true
+            identity.isClient = true;
+            Assert.That(emptyBehaviour.isServer, Is.False);
+            Assert.That(emptyBehaviour.isClient, Is.True);
+            Assert.That(emptyBehaviour.isClientOnly, Is.True);
+        }
+
+        [Test]
+        public void HasNoAuthorityByDefault()
+        {
+            // no authority by default
+            CreateNetworked(out _, out _, out EmptyBehaviour emptyBehaviour);
+            Assert.That(emptyBehaviour.hasAuthority, Is.False);
+        }
+
+        [Test]
+        public void HasIdentitysNetId()
+        {
+            CreateNetworked(out _, out NetworkIdentity identity, out EmptyBehaviour emptyBehaviour);
+            identity.netId = 42;
+            Assert.That(emptyBehaviour.netId, Is.EqualTo(42));
+        }
+
+        [Test]
+        public void HasIdentitysConnectionToServer()
+        {
+            CreateNetworked(out _, out NetworkIdentity identity, out EmptyBehaviour emptyBehaviour);
+            identity.connectionToServer = new LocalConnectionToServer();
+            Assert.That(emptyBehaviour.connectionToServer, Is.EqualTo(identity.connectionToServer));
+        }
+
+        [Test]
+        public void HasIdentitysConnectionToClient()
+        {
+            CreateNetworked(out _, out NetworkIdentity identity, out EmptyBehaviour emptyBehaviour);
+            identity.connectionToClient = new LocalConnectionToClient();
+            Assert.That(emptyBehaviour.connectionToClient, Is.EqualTo(identity.connectionToClient));
+        }
+
+        [Test]
+        public void ComponentIndex()
+        {
+            // create a NetworkIdentity with two components
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out EmptyBehaviour first, out EmptyBehaviour second);
+            Assert.That(first.ComponentIndex, Is.EqualTo(0));
+            Assert.That(second.ComponentIndex, Is.EqualTo(1));
+        }
+
+        [Test, Ignore("NetworkServerTest.SendCommand does it already")]
+        public void SendCommandInternal() {}
+
+        [Test, Ignore("ClientRpcTest.cs tests Rpcs already")]
+        public void SendRPCInternal() {}
+
+        [Test, Ignore("TargetRpcTest.cs tests TargetRpcs already")]
+        public void SendTargetRPCInternal() {}
+
+        [Test]
+        public void RegisterDelegateDoesntOverwrite()
+        {
+            // registerdelegate is protected, but we can use
+            // RegisterCommandDelegate which calls RegisterDelegate
+            int registeredHash1 = RemoteProcedureCalls.RegisterDelegate(
+                typeof(NetworkBehaviourDelegateComponent),
+                nameof(NetworkBehaviourDelegateComponent.Delegate),
+                RemoteCallType.Command,
+                NetworkBehaviourDelegateComponent.Delegate,
+                false);
+
+            // registering the exact same one should be fine. it should simply
+            // do nothing.
+            int registeredHash2 = RemoteProcedureCalls.RegisterDelegate(
+                typeof(NetworkBehaviourDelegateComponent),
+                nameof(NetworkBehaviourDelegateComponent.Delegate),
+                RemoteCallType.Command,
+                NetworkBehaviourDelegateComponent.Delegate,
+                false);
+
+            // registering the same name with a different callback shouldn't
+            // work
+            LogAssert.Expect(LogType.Error, $"Function {typeof(NetworkBehaviourDelegateComponent)}.{nameof(NetworkBehaviourDelegateComponent.Delegate)} and {typeof(NetworkBehaviourDelegateComponent)}.{nameof(NetworkBehaviourDelegateComponent.Delegate2)} have the same hash.  Please rename one of them");
+            int registeredHash3 = RemoteProcedureCalls.RegisterDelegate(
+                typeof(NetworkBehaviourDelegateComponent),
+                nameof(NetworkBehaviourDelegateComponent.Delegate),
+                RemoteCallType.Command,
+                NetworkBehaviourDelegateComponent.Delegate2,
+                false);
+
+            // clean up
+            RemoteProcedureCalls.RemoveDelegate(registeredHash1);
+            RemoteProcedureCalls.RemoveDelegate(registeredHash2);
+            RemoteProcedureCalls.RemoveDelegate(registeredHash3);
+        }
+
+        [Test]
+        public void GetDelegate()
+        {
+            // registerdelegate is protected, but we can use
+            // RegisterCommandDelegate which calls RegisterDelegate
+            int registeredHash = RemoteProcedureCalls.RegisterDelegate(
+                typeof(NetworkBehaviourDelegateComponent),
+                nameof(NetworkBehaviourDelegateComponent.Delegate),
+                RemoteCallType.Command,
+                NetworkBehaviourDelegateComponent.Delegate,
+                false);
+
+            // get handler
+            int cmdHash = nameof(NetworkBehaviourDelegateComponent.Delegate).GetStableHashCode();
+            RemoteCallDelegate func = RemoteProcedureCalls.GetDelegate(cmdHash);
+            RemoteCallDelegate expected = NetworkBehaviourDelegateComponent.Delegate;
+            Assert.That(func, Is.EqualTo(expected));
+
+            // invalid hash should return null handler
+            RemoteCallDelegate funcNull = RemoteProcedureCalls.GetDelegate(1234);
+            Assert.That(funcNull, Is.Null);
+
+            // clean up
+            RemoteProcedureCalls.RemoveDelegate(registeredHash);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualZeroNetIdNullIsTrue()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+            // null and identity.netid==0 returns true (=equal)
+            //
+            // later we should reevaluate if this is so smart or not. might be
+            // better to return false here.
+            // => we possibly return false so that resync doesn't happen when
+            //    GO disappears? or not?
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(null, identity.netId);
+            Assert.That(result, Is.True);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualNull()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // null should return false
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(null, identity.netId);
+            Assert.That(result, Is.False);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualZeroNetIdAndGOWithoutIdentityComponentIsTrue()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+            CreateNetworked(out GameObject go, out NetworkIdentity _);
+
+            // null and identity.netid==0 returns true (=equal)
+            //
+            // later we should reevaluate if this is so smart or not. might be
+            // better to return false here.
+            // => we possibly return false so that resync doesn't happen when
+            //    GO disappears? or not?
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(go, identity.netId);
+            Assert.That(result, Is.True);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualWithoutIdentityComponent()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // gameobject without networkidentity component should return false
+            CreateNetworked(out GameObject go, out NetworkIdentity _);
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(go, identity.netId);
+            Assert.That(result, Is.False);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualValidGOWithDifferentNetId()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // gameobject with valid networkidentity and netid that is different
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            ni.netId = 43;
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(go, identity.netId);
+            Assert.That(result, Is.False);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualValidGOWithSameNetId()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // gameobject with valid networkidentity and netid that is different
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            ni.netId = 42;
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(go, identity.netId);
+            Assert.That(result, Is.True);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualUnspawnedGO()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // gameobject with valid networkidentity and 0 netid that is unspawned
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            LogAssert.Expect(LogType.Warning, $"SetSyncVarGameObject GameObject {go} has a zero netId. Maybe it is not spawned yet?");
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(go, identity.netId);
+            Assert.That(result, Is.False);
+        }
+
+        // NOTE: SyncVarGameObjectEqual should be static later
+        [Test]
+        public void SyncVarGameObjectEqualUnspawnedGOZeroNetIdIsTrue()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // unspawned go and identity.netid==0 returns true (=equal)
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            LogAssert.Expect(LogType.Warning, $"SetSyncVarGameObject GameObject {go} has a zero netId. Maybe it is not spawned yet?");
+            bool result = NetworkBehaviour.SyncVarGameObjectEqual(go, identity.netId);
+            Assert.That(result, Is.True);
+        }
+
+        // NOTE: SyncVarNetworkIdentityEqual should be static later
+        [Test]
+        public void SyncVarNetworkIdentityEqualZeroNetIdNullIsTrue()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // null and identity.netid==0 returns true (=equal)
+            //
+            // later we should reevaluate if this is so smart or not. might be
+            // better to return false here.
+            // => we possibly return false so that resync doesn't happen when
+            //    GO disappears? or not?
+            bool result = NetworkBehaviour.SyncVarNetworkIdentityEqual(null, identity.netId);
+            Assert.That(result, Is.True);
+        }
+
+        // NOTE: SyncVarNetworkIdentityEqual should be static later
+        [Test]
+        public void SyncVarNetworkIdentityEqualNull()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // null should return false
+            bool result = NetworkBehaviour.SyncVarNetworkIdentityEqual(null, identity.netId);
+            Assert.That(result, Is.False);
+        }
+
+        // NOTE: SyncVarNetworkIdentityEqual should be static later
+        [Test]
+        public void SyncVarNetworkIdentityEqualValidIdentityWithDifferentNetId()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // gameobject with valid networkidentity and netid that is different
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            ni.netId = 43;
+            bool result = NetworkBehaviour.SyncVarNetworkIdentityEqual(ni, identity.netId);
+            Assert.That(result, Is.False);
+        }
+
+        // NOTE: SyncVarNetworkIdentityEqual should be static later
+        [Test]
+        public void SyncVarNetworkIdentityEqualValidIdentityWithSameNetId()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // gameobject with valid networkidentity and netid that is different
+            CreateNetworked(out GameObject _, out NetworkIdentity ni);
+            ni.netId = 42;
+            bool result = NetworkBehaviour.SyncVarNetworkIdentityEqual(ni, identity.netId);
+            Assert.That(result, Is.True);
+        }
+
+        // NOTE: SyncVarNetworkIdentityEqual should be static later
+        [Test]
+        public void SyncVarNetworkIdentityEqualUnspawnedIdentity()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // our identity should have a netid for comparing
+            identity.netId = 42;
+
+            // gameobject with valid networkidentity and 0 netid that is unspawned
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            LogAssert.Expect(LogType.Warning, $"SetSyncVarNetworkIdentity NetworkIdentity {ni} has a zero netId. Maybe it is not spawned yet?");
+            bool result = NetworkBehaviour.SyncVarNetworkIdentityEqual(ni, identity.netId);
+            Assert.That(result, Is.False);
+        }
+
+        // NOTE: SyncVarNetworkIdentityEqual should be static later
+        [Test]
+        public void SyncVarNetworkIdentityEqualUnspawnedIdentityZeroNetIdIsTrue()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // unspawned go and identity.netid==0 returns true (=equal)
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            LogAssert.Expect(LogType.Warning, $"SetSyncVarNetworkIdentity NetworkIdentity {ni} has a zero netId. Maybe it is not spawned yet?");
+            bool result = NetworkBehaviour.SyncVarNetworkIdentityEqual(ni, identity.netId);
+            Assert.That(result, Is.True);
+        }
+
+        [Test]
+        public void SetSyncVarGameObjectWithValidObject()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourSetSyncVarGameObjectComponent comp);
+
+            // create a valid GameObject with networkidentity and netid
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            ni.netId = 43;
+
+            // set the GameObject SyncVar
+            Assert.That(comp.IsDirty(), Is.False);
+            comp.SetSyncVarGameObjectExposed(go, 1ul);
+            Assert.That(comp.test, Is.EqualTo(go));
+            Assert.That(comp.testNetId, Is.EqualTo(ni.netId));
+            Assert.That(comp.IsDirty(), Is.True);
+        }
+
+        [Test]
+        public void SetSyncVarGameObjectNull()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourSetSyncVarGameObjectComponent comp);
+
+            // set some existing GO+netId first to check if it is going to be
+            // overwritten
+            CreateGameObject(out GameObject go);
+            comp.test = go;
+            comp.testNetId = 43;
+
+            // set the GameObject SyncVar to null
+            Assert.That(comp.IsDirty(), Is.False);
+            comp.SetSyncVarGameObjectExposed(null, 1ul);
+            Assert.That(comp.test, Is.EqualTo(null));
+            Assert.That(comp.testNetId, Is.EqualTo(0));
+            Assert.That(comp.IsDirty(), Is.True);
+        }
+
+        [Test]
+        public void SetSyncVarGameObjectWithoutNetworkIdentity()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourSetSyncVarGameObjectComponent comp);
+
+            // set some existing GO+netId first to check if it is going to be
+            // overwritten
+            CreateGameObject(out GameObject go);
+            comp.test = go;
+            comp.testNetId = 43;
+
+            // create test GO with no networkidentity
+            CreateGameObject(out GameObject test);
+
+            // set the GameObject SyncVar to 'test' GO without netidentity.
+            // -> the way it currently works is that it sets netId to 0, but
+            //    it DOES set gameObjectField to the GameObject without the
+            //    NetworkIdentity, instead of setting it to null because it's
+            //    seemingly invalid.
+            // -> there might be a deeper reason why UNET did that. perhaps for
+            //    cases where we assign a GameObject before the network was
+            //    fully started and has no netId or networkidentity yet etc.
+            // => it works, so let's keep it for now
+            Assert.That(comp.IsDirty(), Is.False);
+            comp.SetSyncVarGameObjectExposed(test, 1ul);
+            Assert.That(comp.test, Is.EqualTo(test));
+            Assert.That(comp.testNetId, Is.EqualTo(0));
+            Assert.That(comp.IsDirty(), Is.True);
+        }
+
+        [Test]
+        public void SetSyncVarGameObjectZeroNetId()
+        {
+            CreateNetworked(out GameObject gameObject, out NetworkIdentity identity, out NetworkBehaviourSetSyncVarGameObjectComponent comp);
+
+            // set some existing GO+netId first to check if it is going to be
+            // overwritten
+            CreateGameObject(out GameObject go);
+            comp.test = go;
+            comp.testNetId = 43;
+
+            // create test GO with networkidentity and zero netid
+            CreateNetworked(out GameObject test, out NetworkIdentity ni);
+            Assert.That(ni.netId, Is.EqualTo(0));
+
+            // set the GameObject SyncVar to 'test' GO with zero netId.
+            // -> the way it currently works is that it sets netId to 0, but
+            //    it DOES set gameObjectField to the GameObject without the
+            //    NetworkIdentity, instead of setting it to null because it's
+            //    seemingly invalid.
+            // -> there might be a deeper reason why UNET did that. perhaps for
+            //    cases where we assign a GameObject before the network was
+            //    fully started and has no netId or networkidentity yet etc.
+            // => it works, so let's keep it for now
+            Assert.That(comp.IsDirty(), Is.False);
+            LogAssert.Expect(LogType.Warning, $"SetSyncVarGameObject GameObject {test} has a zero netId. Maybe it is not spawned yet?");
+            comp.SetSyncVarGameObjectExposed(test, 1ul);
+            Assert.That(comp.test, Is.EqualTo(test));
+            Assert.That(comp.testNetId, Is.EqualTo(0));
+            Assert.That(comp.IsDirty(), Is.True);
+        }
+
+        [Test]
+        public void GetSyncVarGameObjectOnServer()
+        {
+            CreateNetworked(out GameObject gameObject, out NetworkIdentity identity, out NetworkBehaviourGetSyncVarGameObjectComponent comp);
+
+            // call OnStartServer so isServer is true
+            identity.OnStartServer();
+            Assert.That(identity.isServer, Is.True);
+
+            // create a syncable GameObject
+            CreateNetworked(out GameObject go, out NetworkIdentity ni);
+            ni.netId = identity.netId + 1;
+
+            // assign it in the component
+            comp.test = go;
+            comp.testNetId = ni.netId;
+
+            // get it on the server. should simply return the field instead of
+            // doing any netId lookup like on the client
+            GameObject result = comp.GetSyncVarGameObjectExposed();
+            Assert.That(result, Is.EqualTo(go));
+
+            // clean up: set isServer false first, otherwise Destroy instead of DestroyImmediate is called
+            identity.netId = 0;
+        }
+
+        [Test]
+        public void GetSyncVarGameObjectOnServerNull()
+        {
+            CreateNetworked(out GameObject gameObject, out NetworkIdentity identity, out NetworkBehaviourGetSyncVarGameObjectComponent comp);
+
+            // call OnStartServer and assign netId so isServer is true
+            identity.OnStartServer();
+            Assert.That(identity.isServer, Is.True);
+
+            // get it on the server. null should work fine.
+            GameObject result = comp.GetSyncVarGameObjectExposed();
+            Assert.That(result, Is.Null);
+        }
+
+        [Test]
+        public void GetSyncVarGameObjectOnClient()
+        {
+            // start server & connect client because we need spawn functions
+            NetworkServer.Listen(1);
+            ConnectClientBlockingAuthenticatedAndReady(out _);
+
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // are we on client and not on server?
+            identity.isClient = true;
+            Assert.That(identity.isServer, Is.False);
+
+            // create a networked object with test component
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourGetSyncVarGameObjectComponent comp);
+
+            // create a spawned, syncable GameObject
+            // (client tries to look up via netid, so needs to be spawned)
+            CreateNetworkedAndSpawn(
+                out GameObject serverGO, out NetworkIdentity serverIdentity,
+                out GameObject clientGO, out NetworkIdentity clientIdentity);
+
+            // assign ONLY netId in the component. assume that GameObject was
+            // assigned earlier but client walked so far out of range that it
+            // was despawned on the client. so it's forced to do the netId look-
+            // up.
+            Assert.That(comp.test, Is.Null);
+            comp.testNetId = clientIdentity.netId;
+
+            // get it on the client. should look up netId in spawned
+            GameObject result = comp.GetSyncVarGameObjectExposed();
+            Assert.That(result, Is.EqualTo(clientGO));
+        }
+
+        [Test]
+        public void GetSyncVarGameObjectOnClientNull()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity);
+
+            // are we on client and not on server?
+            identity.isClient = true;
+            Assert.That(identity.isServer, Is.False);
+
+            // create a networked object with test component
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourGetSyncVarGameObjectComponent comp);
+
+            // get it on the client. null should be supported.
+            GameObject result = comp.GetSyncVarGameObjectExposed();
+            Assert.That(result, Is.Null);
+        }
+
+        [Test]
+        public void SetSyncVarNetworkIdentityWithValidObject()
+        {
+            // create a networked object with test component
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourSetSyncVarNetworkIdentityComponent comp);
+
+            // create a valid GameObject with networkidentity and netid
+            CreateNetworked(out GameObject _, out NetworkIdentity ni);
+            ni.netId = 43;
+
+            // set the NetworkIdentity SyncVar
+            Assert.That(comp.IsDirty(), Is.False);
+            comp.SetSyncVarNetworkIdentityExposed(ni, 1ul);
+            Assert.That(comp.test, Is.EqualTo(ni));
+            Assert.That(comp.testNetId, Is.EqualTo(ni.netId));
+            Assert.That(comp.IsDirty(), Is.True);
+        }
+
+        [Test]
+        public void SetSyncVarNetworkIdentityNull()
+        {
+            // create a networked object with test component
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourSetSyncVarNetworkIdentityComponent comp);
+
+            // set some existing NI+netId first to check if it is going to be
+            // overwritten
+            CreateNetworked(out GameObject _, out NetworkIdentity ni);
+            comp.test = ni;
+            comp.testNetId = 43;
+
+            // set the NetworkIdentity SyncVar to null
+            Assert.That(comp.IsDirty(), Is.False);
+            comp.SetSyncVarNetworkIdentityExposed(null, 1ul);
+            Assert.That(comp.test, Is.EqualTo(null));
+            Assert.That(comp.testNetId, Is.EqualTo(0));
+            Assert.That(comp.IsDirty(), Is.True);
+        }
+
+        [Test]
+        public void SetSyncVarNetworkIdentityZeroNetId()
+        {
+            CreateNetworked(out _, out _, out NetworkBehaviourSetSyncVarNetworkIdentityComponent comp);
+
+            // set some existing NI+netId first to check if it is going to be
+            // overwritten
+            CreateNetworked(out GameObject _, out NetworkIdentity ni);
+            comp.test = ni;
+            comp.testNetId = 43;
+
+            // create test GO with networkidentity and zero netid
+            CreateNetworked(out GameObject _, out NetworkIdentity testNi);
+            Assert.That(testNi.netId, Is.EqualTo(0));
+
+            // set the NetworkIdentity SyncVar to 'test' GO with zero netId.
+            // -> the way it currently works is that it sets netId to 0, but
+            //    it DOES set gameObjectField to the GameObject without the
+            //    NetworkIdentity, instead of setting it to null because it's
+            //    seemingly invalid.
+            // -> there might be a deeper reason why UNET did that. perhaps for
+            //    cases where we assign a GameObject before the network was
+            //    fully started and has no netId or networkidentity yet etc.
+            // => it works, so let's keep it for now
+            Assert.That(comp.IsDirty(), Is.False);
+            LogAssert.Expect(LogType.Warning, $"SetSyncVarNetworkIdentity NetworkIdentity {testNi} has a zero netId. Maybe it is not spawned yet?");
+            comp.SetSyncVarNetworkIdentityExposed(testNi, 1ul);
+            Assert.That(comp.test, Is.EqualTo(testNi));
+            Assert.That(comp.testNetId, Is.EqualTo(0));
+            Assert.That(comp.IsDirty(), Is.True);
+        }
+
+        [Test]
+        public void GetSyncVarNetworkIdentityOnServer()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity, out NetworkBehaviourGetSyncVarNetworkIdentityComponent comp);
+
+            // call OnStartServer so isServer is true
+            identity.OnStartServer();
+            Assert.That(identity.isServer, Is.True);
+
+            // create a syncable GameObject
+            CreateNetworked(out _, out NetworkIdentity ni);
+            ni.netId = identity.netId + 1;
+
+            // assign it in the component
+            comp.test = ni;
+            comp.testNetId = ni.netId;
+
+            // get it on the server. should simply return the field instead of
+            // doing any netId lookup like on the client
+            NetworkIdentity result = comp.GetSyncVarNetworkIdentityExposed();
+            Assert.That(result, Is.EqualTo(ni));
+        }
+
+        [Test]
+        public void GetSyncVarNetworkIdentityOnServerNull()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity, out NetworkBehaviourGetSyncVarNetworkIdentityComponent comp);
+
+            // call OnStartServer so isServer is true
+            identity.OnStartServer();
+            Assert.That(identity.isServer, Is.True);
+
+            // get it on the server. null should work fine.
+            NetworkIdentity result = comp.GetSyncVarNetworkIdentityExposed();
+            Assert.That(result, Is.Null);
+        }
+
+        [Test]
+        public void GetSyncVarNetworkIdentityOnClient()
+        {
+            // start server & connect client because we need spawn functions
+            NetworkServer.Listen(1);
+            ConnectClientBlockingAuthenticatedAndReady(out _);
+
+            CreateNetworked(out GameObject _, out NetworkIdentity identity, out NetworkBehaviourGetSyncVarNetworkIdentityComponent comp);
+
+            // are we on client and not on server?
+            identity.isClient = true;
+            Assert.That(identity.isServer, Is.False);
+
+            // create a spawned, syncable GameObject
+            // (client tries to look up via netid, so needs to be spawned)
+            CreateNetworkedAndSpawn(
+                out _, out NetworkIdentity serverIdentity,
+                out _, out NetworkIdentity clientIdentity);
+
+            // assign ONLY netId in the component. assume that GameObject was
+            // assigned earlier but client walked so far out of range that it
+            // was despawned on the client. so it's forced to do the netId look-
+            // up.
+            Assert.That(comp.test, Is.Null);
+            comp.testNetId = clientIdentity.netId;
+
+            // get it on the client. should look up netId in spawned
+            NetworkIdentity result = comp.GetSyncVarNetworkIdentityExposed();
+            Assert.That(result, Is.EqualTo(clientIdentity));
+        }
+
+        [Test]
+        public void GetSyncVarNetworkIdentityOnClientNull()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity, out NetworkBehaviourGetSyncVarNetworkIdentityComponent comp);
+
+            // are we on client and not on server?
+            identity.isClient = true;
+            Assert.That(identity.isServer, Is.False);
+
+            // get it on the client. null should be supported.
+            NetworkIdentity result = comp.GetSyncVarNetworkIdentityExposed();
+            Assert.That(result, Is.Null);
+        }
+
+        [Test]
+        public void SerializeAndDeserializeObjectsAll()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity _, out NetworkBehaviourWithSyncVarsAndCollections comp);
+
+            // add values to synclist
+            comp.list.Add(42);
+            comp.list.Add(43);
+
+            // serialize it
+            NetworkWriter writer = new NetworkWriter();
+            comp.SerializeObjectsAll(writer);
+
+            // clear original list
+            comp.list.Clear();
+            Assert.That(comp.list.Count, Is.EqualTo(0));
+
+            // deserialize it
+            NetworkReader reader = new NetworkReader(writer.ToArray());
+            comp.DeSerializeObjectsAll(reader);
+            Assert.That(comp.list.Count, Is.EqualTo(2));
+            Assert.That(comp.list[0], Is.EqualTo(42));
+            Assert.That(comp.list[1], Is.EqualTo(43));
+        }
+
+        [Test]
+        public void SerializeAndDeserializeObjectsDelta()
+        {
+            // SyncLists are only set dirty while owner has observers.
+            // need a connection.
+            NetworkServer.Listen(1);
+            ConnectHostClientBlockingAuthenticatedAndReady();
+
+            CreateNetworkedAndSpawn(out GameObject _, out NetworkIdentity _, out NetworkBehaviourWithSyncVarsAndCollections comp);
+
+            // add to synclist
+            comp.list.Add(42);
+            comp.list.Add(43);
+
+            // serialize it
+            NetworkWriter writer = new NetworkWriter();
+            comp.SerializeObjectsDelta(writer);
+
+            // clear original list
+            comp.list.Clear();
+            Assert.That(comp.list.Count, Is.EqualTo(0));
+
+            // deserialize it
+            NetworkReader reader = new NetworkReader(writer.ToArray());
+            comp.DeSerializeObjectsDelta(reader);
+            Assert.That(comp.list.Count, Is.EqualTo(2));
+            Assert.That(comp.list[0], Is.EqualTo(42));
+            Assert.That(comp.list[1], Is.EqualTo(43));
+        }
+
+        [Test]
+        public void OnStopClient()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity, out OnStopClientComponent comp);
+            identity.OnStopClient();
+            Assert.That(comp.called, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void OnStartClient()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity, out OnStartClientComponent comp);
+            identity.OnStartClient();
+            Assert.That(comp.called, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void OnStartLocalPlayer()
+        {
+            CreateNetworked(out GameObject _, out NetworkIdentity identity, out OnStartLocalPlayerComponent comp);
+            identity.OnStartLocalPlayer();
+            Assert.That(comp.called, Is.EqualTo(1));
+        }
+    }
+
+    // we need to inherit from networkbehaviour to test protected functions
+    public class NetworkBehaviourInitSyncObjectTester : NetworkBehaviour
+    {
+        [Test]
+        public void InitSyncObject()
+        {
+            SyncObject syncObject = new SyncList<bool>();
+            InitSyncObject(syncObject);
+            Assert.That(syncObjects.Count, Is.EqualTo(1));
+            Assert.That(syncObjects[0], Is.EqualTo(syncObject));
+        }
+    }
+}

Assets/Mirror/Tests/Editor/NetworkBehaviourTests.cs.meta

@@ -0,0 +1,11 @@
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+guid: 0e4164d273d6e4d71bd39cc246f454b2
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Mirror/Tests/Editor/NetworkClientTests.cs

@@ -0,0 +1,128 @@
+using System;
+using NUnit.Framework;
+
+namespace Mirror.Tests
+{
+    public class NetworkClientTests : MirrorEditModeTest
+    {
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+            // we need a server to connect to
+            NetworkServer.Listen(10);
+        }
+
+        [Test]
+        public void ServerIp()
+        {
+            NetworkClient.ConnectHost();
+            Assert.That(NetworkClient.serverIp, Is.EqualTo("localhost"));
+        }
+
+        [Test]
+        public void IsConnected()
+        {
+            Assert.That(NetworkClient.isConnected, Is.False);
+            NetworkClient.ConnectHost();
+            Assert.That(NetworkClient.isConnected, Is.True);
+        }
+
+        [Test]
+        public void ConnectUri()
+        {
+            NetworkClient.Connect(new Uri("memory://localhost"));
+            // update transport so connect event is processed
+            UpdateTransport();
+            Assert.That(NetworkClient.isConnected, Is.True);
+        }
+
+        [Test]
+        public void DisconnectInHostMode()
+        {
+            NetworkClient.ConnectHost();
+            Assert.That(NetworkClient.isConnected, Is.True);
+            Assert.That(NetworkServer.localConnection, !Is.Null);
+
+            NetworkClient.Disconnect();
+            Assert.That(NetworkClient.isConnected, Is.False);
+            Assert.That(NetworkServer.localConnection, Is.Null);
+        }
+
+        [Test, Ignore("NetworkServerTest.SendClientToServerMessage does it already")]
+        public void Send() {}
+
+        // test to guarantee Disconnect() eventually calls OnClientDisconnected.
+        // prevents https://github.com/vis2k/Mirror/issues/2818 forever.
+        // previously there was a bug where:
+        // - Disconnect() sets state = Disconnected
+        // - Transport processes it
+        // - OnTransportDisconnected() early returns because
+        //   state == Disconnected already, so it wouldn't call the event.
+        [Test]
+        public void DisconnectCallsOnClientDisconnected_Remote()
+        {
+            // setup hook
+            bool called = false;
+            NetworkClient.OnDisconnectedEvent = () => called = true;
+
+            // connect
+            ConnectClientBlocking(out _);
+
+            // disconnect & process everything
+            NetworkClient.Disconnect();
+            UpdateTransport();
+
+            // was it called?
+            Assert.That(called, Is.True);
+        }
+
+        // same as above, but for host mode
+        // prevents https://github.com/vis2k/Mirror/issues/2818 forever.
+        [Test]
+        public void DisconnectCallsOnClientDisconnected_HostMode()
+        {
+            // setup hook
+            bool called = false;
+            NetworkClient.OnDisconnectedEvent = () => called = true;
+
+            // connect host
+            NetworkClient.ConnectHost();
+
+            // disconnect & process everything
+            NetworkClient.Disconnect();
+            UpdateTransport();
+
+            // was it called?
+            Assert.That(called, Is.True);
+        }
+
+        [Test]
+        public void ShutdownCleanup()
+        {
+            // add some test event hooks to make sure they are cleaned up.
+            // there used to be a bug where they wouldn't be cleaned up.
+            NetworkClient.OnConnectedEvent = () => {};
+            NetworkClient.OnDisconnectedEvent = () => {};
+
+            NetworkClient.Shutdown();
+
+            Assert.That(NetworkClient.handlers.Count, Is.EqualTo(0));
+            Assert.That(NetworkClient.spawned.Count, Is.EqualTo(0));
+            Assert.That(NetworkClient.spawnableObjects.Count, Is.EqualTo(0));
+
+            Assert.That(NetworkClient.connectState, Is.EqualTo(ConnectState.None));
+
+            Assert.That(NetworkClient.connection, Is.Null);
+            Assert.That(NetworkClient.localPlayer, Is.Null);
+
+            Assert.That(NetworkClient.ready, Is.False);
+            Assert.That(NetworkClient.isSpawnFinished, Is.False);
+            Assert.That(NetworkClient.isLoadingScene, Is.False);
+
+            Assert.That(NetworkClient.OnConnectedEvent, Is.Null);
+            Assert.That(NetworkClient.OnDisconnectedEvent, Is.Null);
+            Assert.That(NetworkClient.OnErrorEvent, Is.Null);
+        }
+    }
+}