fix: Don't let exceptions in OnNetworkSpawn/OnNetworkDespawn block processing of the next callback. [MTT-1378]

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -27,6 +27,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 - Fixed NetworkList to properly call INetworkSerializable's NetworkSerialize() method (#1682)
 - Fixed The NetworkConfig's checksum hash includes the NetworkTick so that clients with a different tickrate than the server are identified and not allowed to connect (#1728)
 - Fixed OwnedObjects not being properly modified when using ChangeOwnership (#1731)
+- Fixed throwing an exception in OnNetworkUpdate causing other OnNetworkUpdate calls to not be executed. (#1739)
 
 ## [1.0.0-pre.5] - 2022-01-26
 

com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs

@@ -796,7 +796,14 @@ internal void InvokeBehaviourNetworkSpawn()
             for (int i = 0; i < ChildNetworkBehaviours.Count; i++)
             {
                 ChildNetworkBehaviours[i].InternalOnNetworkSpawn();
-                ChildNetworkBehaviours[i].OnNetworkSpawn();
+                try
+                {
+                    ChildNetworkBehaviours[i].OnNetworkSpawn();
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e);
+                }
             }
         }
 
@@ -805,7 +812,14 @@ internal void InvokeBehaviourNetworkDespawn()
             for (int i = 0; i < ChildNetworkBehaviours.Count; i++)
             {
                 ChildNetworkBehaviours[i].InternalOnNetworkDespawn();
-                ChildNetworkBehaviours[i].OnNetworkDespawn();
+                try
+                {
+                    ChildNetworkBehaviours[i].OnNetworkDespawn();
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e);
+                }
             }
         }
 

testproject/Assets/Tests/Runtime/OnNetworkSpawnExceptionTests.cs

@@ -0,0 +1,106 @@
+using System;
+using System.Collections;
+using Unity.Netcode;
+using Unity.Netcode.RuntimeTests;
+using UnityEngine;
+using UnityEngine.Assertions;
+using UnityEngine.TestTools;
+
+namespace TestProject.RuntimeTests
+{
+
+    public class OnNetworkSpawnThrowsExceptionComponent : NetworkBehaviour
+    {
+        public static int NumClientSpawns = 0;
+        public override void OnNetworkSpawn()
+        {
+            if (IsClient)
+            {
+                ++NumClientSpawns;
+                if (NumClientSpawns > 2)
+                {
+                    throw new Exception("I'm misbehaving");
+                }
+            }
+        }
+    }
+    public class OnNetworkDespawnThrowsExceptionComponent : NetworkBehaviour
+    {
+        public static int NumClientDespawns = 0;
+        public override void OnNetworkDespawn()
+        {
+            if (IsClient)
+            {
+                ++NumClientDespawns;
+                if (NumClientDespawns > 2)
+                {
+                    throw new Exception("I'm misbehaving");
+                }
+            }
+        }
+
+    }
+    public class OnNetworkSpawnExceptionTests : BaseMultiInstanceTest
+    {
+        private GameObject m_Prefab;
+        private GameObject[] m_Objects = new GameObject[5];
+
+        [UnityTest]
+        public IEnumerator WhenOnNetworkSpawnThrowsException_FutureOnNetworkSpawnsAreNotPrevented()
+        {
+            //Spawning was done during setup
+            Assert.AreEqual(5, OnNetworkSpawnThrowsExceptionComponent.NumClientSpawns);
+            yield return null;
+        }
+
+        [UnityTest]
+        public IEnumerator WhenOnNetworkDespawnThrowsException_FutureOnNetworkDespawnsAreNotPrevented()
+        {
+            //Spawning was done during setup. Now we despawn.
+            for (var i = 0; i < 5; ++i)
+            {
+                m_Objects[i].GetComponent<NetworkObject>().Despawn();
+            }
+
+            var result = new MultiInstanceHelpers.CoroutineResultWrapper<bool>();
+            yield return MultiInstanceHelpers.Run(
+                MultiInstanceHelpers.WaitForCondition(
+                    () => OnNetworkDespawnThrowsExceptionComponent.NumClientDespawns == 5, result));
+            Assert.IsTrue(result.Result);
+        }
+
+        public override IEnumerator Setup()
+        {
+            yield return StartSomeClientsAndServerWithPlayers(true, NbClients, _ =>
+            {
+                m_Prefab = new GameObject();
+                var networkObject = m_Prefab.AddComponent<NetworkObject>();
+                m_Prefab.AddComponent<OnNetworkSpawnThrowsExceptionComponent>();
+                MultiInstanceHelpers.MakeNetworkObjectTestPrefab(networkObject);
+
+                var validNetworkPrefab = new NetworkPrefab();
+                validNetworkPrefab.Prefab = m_Prefab;
+                m_ServerNetworkManager.NetworkConfig.NetworkPrefabs.Add(validNetworkPrefab);
+                foreach (var client in m_ClientNetworkManagers)
+                {
+                    client.NetworkConfig.NetworkPrefabs.Add(validNetworkPrefab);
+                }
+            });
+
+            for (var i = 0; i < 5; ++i)
+            {
+                var obj = UnityEngine.Object.Instantiate(m_Prefab);
+                m_Objects[i] = obj;
+                obj.GetComponent<NetworkObject>().NetworkManagerOwner = m_ServerNetworkManager;
+                obj.GetComponent<NetworkObject>().Spawn();
+            }
+
+            var result = new MultiInstanceHelpers.CoroutineResultWrapper<bool>();
+            MultiInstanceHelpers.Run(
+                MultiInstanceHelpers.WaitForCondition(
+                    () => OnNetworkSpawnThrowsExceptionComponent.NumClientSpawns == 5, result));
+            Assert.IsTrue(result.Result);
+        }
+        protected override int NbClients => 1;
+    }
+}