chore: [2.x] Add NetworkTransform parenting test (#3368)

1. Adds a test replicating the bug fixed in #3361 
2. Move the code to sync prefabs for late joining clients into the base
`NetcodeIntegrationTest`
3. Fix some pvp exceptions

## Changelog

- Added: Test covering the bug fixed in #3361

## Testing and Documentation

- Adds Unit test

---------

Co-authored-by: Noel Stephens <noel.stephens@unity3d.com>

Author: EmandM

com.unity.netcode.gameobjects/TestHelpers/Runtime/NetcodeIntegrationTest.cs

@@ -466,14 +466,24 @@ private void AddRemoveNetworkManager(NetworkManager networkManager, bool addNetw
         /// CreateAndStartNewClient Only
         /// Invoked when the newly created client has been created
         /// </summary>
+        /// <param name="networkManager">The NetworkManager instance of the client.</param>
         protected virtual void OnNewClientCreated(NetworkManager networkManager)
         {
+            // Ensure any late joining client has all NetworkPrefabs required to connect.
+            foreach (var networkPrefab in m_ServerNetworkManager.NetworkConfig.Prefabs.Prefabs)
+            {
+                if (!networkManager.NetworkConfig.Prefabs.Contains(networkPrefab.Prefab))
+                {
+                    networkManager.NetworkConfig.Prefabs.Add(networkPrefab);
+                }
+            }
         }
 
         /// <summary>
         /// CreateAndStartNewClient Only
         /// Invoked when the newly created client has been created and started
         /// </summary>
+        /// <param name="networkManager">The NetworkManager instance of the client.</param>
         protected virtual void OnNewClientStarted(NetworkManager networkManager)
         {
         }
@@ -483,6 +493,7 @@ protected virtual void OnNewClientStarted(NetworkManager networkManager)
         /// Invoked when the newly created client has been created, started, and connected
         /// to the server-host.
         /// </summary>
+        /// <param name="networkManager">The NetworkManager instance of the client.</param>
         protected virtual void OnNewClientStartedAndConnected(NetworkManager networkManager)
         {
         }
@@ -494,6 +505,8 @@ protected virtual void OnNewClientStartedAndConnected(NetworkManager networkMana
         /// <remarks>
         /// Use this for testing connection and disconnection scenarios
         /// </remarks>
+        /// <param name="networkManager">The NetworkManager instance of the client.</param>
+        /// <returns>True if the test should wait for the client to connect; otherwise, false.</returns>
         protected virtual bool ShouldWaitForNewClientToConnect(NetworkManager networkManager)
         {
             return true;
@@ -503,6 +516,7 @@ protected virtual bool ShouldWaitForNewClientToConnect(NetworkManager networkMan
         /// This will create, start, and connect a new client while in the middle of an
         /// integration test.
         /// </summary>
+        /// <returns>An IEnumerator to be used in a coroutine for asynchronous execution.</returns>
         protected IEnumerator CreateAndStartNewClient()
         {
             var networkManager = NetcodeIntegrationTestHelpers.CreateNewClient(m_ClientNetworkManagers.Length, m_EnableTimeTravel);

com.unity.netcode.gameobjects/Tests/Runtime/DeferredMessagingTests.cs

@@ -259,8 +259,7 @@ protected override void OnNewClientCreated(NetworkManager networkManager)
             {
                 AddPrefabsToClient(networkManager);
             }
-
-            base.OnNewClientCreated(networkManager);
+            // Don't call base to avoid synchronizing the prefabs
         }
 
         private void SpawnClients(bool clearTestDeferredMessageManagerCallFlags = true)

com.unity.netcode.gameobjects/Tests/Runtime/DistributedAuthority/DistributeObjectsTests.cs

@@ -235,12 +235,6 @@ private bool ValidateTransformsMatch()
             return true;
         }
 
-        protected override void OnNewClientCreated(NetworkManager networkManager)
-        {
-            networkManager.NetworkConfig.Prefabs = m_ServerNetworkManager.NetworkConfig.Prefabs;
-            base.OnNewClientCreated(networkManager);
-        }
-
         private bool SpawnCountsMatch()
         {
             var passed = true;

com.unity.netcode.gameobjects/Tests/Runtime/DistributedAuthority/ExtendedNetworkShowAndHideTests.cs

@@ -97,7 +97,6 @@ protected override void OnNewClientCreated(NetworkManager networkManager)
         {
             m_LateJoinClient = networkManager;
             networkManager.NetworkConfig.EnableSceneManagement = m_EnableSceneManagement;
-            networkManager.NetworkConfig.Prefabs = m_SpawnOwner.NetworkConfig.Prefabs;
             base.OnNewClientCreated(networkManager);
         }
 

com.unity.netcode.gameobjects/Tests/Runtime/DistributedAuthority/NetworkClientAndPlayerObjectTests.cs

@@ -45,7 +45,6 @@ protected override void OnServerAndClientsCreated()
 
         protected override void OnNewClientCreated(NetworkManager networkManager)
         {
-            networkManager.NetworkConfig.Prefabs = m_ServerNetworkManager.NetworkConfig.Prefabs;
             if (m_DistributedAuthority)
             {
                 networkManager.OnFetchLocalPlayerPrefabToSpawn = FetchPlayerPrefabToSpawn;

com.unity.netcode.gameobjects/Tests/Runtime/NetworkBehaviourPrePostSpawnTests.cs

@@ -93,12 +93,6 @@ protected override IEnumerator OnSetup()
             return base.OnSetup();
         }
 
-        protected override void OnNewClientCreated(NetworkManager networkManager)
-        {
-            networkManager.NetworkConfig.Prefabs = m_ServerNetworkManager.NetworkConfig.Prefabs;
-            base.OnNewClientCreated(networkManager);
-        }
-
         /// <summary>
         /// This validates that pre spawn can be used to instantiate and assign a NetworkVariable (or other prespawn tasks)
         /// which can be useful for assigning a NetworkVariable value on the server side when the NetworkVariable has owner write permissions.

com.unity.netcode.gameobjects/Tests/Runtime/NetworkObject/NetworkObjectOnSpawnTests.cs

@@ -86,13 +86,6 @@ private bool CheckClientsSideObserverTestObj()
         /// </summary>
         protected override void OnNewClientCreated(NetworkManager networkManager)
         {
-            foreach (var networkPrefab in m_ServerNetworkManager.NetworkConfig.Prefabs.Prefabs)
-            {
-                if (!networkManager.NetworkConfig.Prefabs.Contains(networkPrefab.Prefab))
-                {
-                    networkManager.NetworkConfig.Prefabs.Add(networkPrefab);
-                }
-            }
             networkManager.NetworkConfig.EnableSceneManagement = m_ServerNetworkManager.NetworkConfig.EnableSceneManagement;
             base.OnNewClientCreated(networkManager);
         }

com.unity.netcode.gameobjects/Tests/Runtime/NetworkObject/NetworkObjectSynchronizationTests.cs

@@ -81,21 +81,16 @@ protected override void OnServerAndClientsCreated()
 
         protected override void OnNewClientCreated(NetworkManager networkManager)
         {
+            // Setup late joining client prefabs first
+            base.OnNewClientCreated(networkManager);
+
             networkManager.NetworkConfig.PlayerPrefab = m_PlayerPrefab;
             networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety = m_VariableLengthSafety == VariableLengthSafety.EnabledNetVarSafety;
-            foreach (var networkPrefab in m_ServerNetworkManager.NetworkConfig.Prefabs.Prefabs)
-            {
-                // To simulate a failure, we exclude the m_InValidNetworkPrefab from the connecting
-                // client's side.
-                if (networkPrefab.Prefab.name != m_InValidNetworkPrefab.name)
-                {
-                    networkManager.NetworkConfig.Prefabs.Add(networkPrefab);
-                }
-            }
             // Disable forcing the same prefabs to avoid failed connections
             networkManager.NetworkConfig.ForceSamePrefabs = false;
             networkManager.LogLevel = m_CurrentLogLevel;
-            base.OnNewClientCreated(networkManager);
+            // To simulate a failure, exclude the m_InValidNetworkPrefab from the connecting client's side.
+            networkManager.NetworkConfig.Prefabs.Remove(m_InValidNetworkPrefab);
         }
 
         [UnityTest]

com.unity.netcode.gameobjects/Tests/Runtime/NetworkTransform/NetworkTransformBase.cs

@@ -338,7 +338,6 @@ protected override IEnumerator OnServerAndClientsConnected()
         /// </summary>
         protected override void OnNewClientCreated(NetworkManager networkManager)
         {
-            networkManager.NetworkConfig.Prefabs = m_ServerNetworkManager.NetworkConfig.Prefabs;
             networkManager.NetworkConfig.TickRate = GetTickRate();
             if (m_EnableVerboseDebug)
             {

com.unity.netcode.gameobjects/Tests/Runtime/NetworkTransform/NetworkTransformOwnershipTests.cs

@@ -91,20 +91,6 @@ protected override void OnServerAndClientsCreated()
             base.OnServerAndClientsCreated();
         }
 
-        /// <summary>
-        /// Clients created during a test need to have their prefabs list updated to
-        /// match the server's prefab list.
-        /// </summary>
-        protected override void OnNewClientCreated(NetworkManager networkManager)
-        {
-            foreach (var networkPrefab in m_ServerNetworkManager.NetworkConfig.Prefabs.Prefabs)
-            {
-                networkManager.NetworkConfig.Prefabs.Add(networkPrefab);
-            }
-
-            base.OnNewClientCreated(networkManager);
-        }
-
         private bool ClientIsOwner()
         {
             var clientId = m_ClientNetworkManagers[0].LocalClientId;