feature: allow calling [Command]s on server-only directly. #3450

Assets/Mirror/Editor/Weaver/Processors/CommandProcessor.cs

@@ -10,6 +10,14 @@ public static class CommandProcessor
             // generates code like:
             public void CmdThrust(float thrusting, int spin)
             {
+                // on server-only, allow calling the original function directly.
+                if (isServer && !isClient)
+                {
+                    UserCode_CmdThrust(value);
+                    return;
+                }
+
+                // otherwise send a command message over the network
                 NetworkWriterPooled writer = NetworkWriterPool.Get();
                 writer.Write(thrusting);
                 writer.WritePackedUInt32((uint)spin);
@@ -38,6 +46,32 @@ public static MethodDefinition ProcessCommandCall(WeaverTypes weaverTypes, Write
 
             NetworkBehaviourProcessor.WriteSetupLocals(worker, weaverTypes);
 
+            Instruction skipIfNotServerOnly = worker.Create(OpCodes.Nop);
+
+            // Check if isServer && !isClient
+            // worker.Emit(OpCodes.Ldarg_0); // loads this. for isClient check later
+            worker.Emit(OpCodes.Call, weaverTypes.NetworkServerGetActive); // TODO isServer?
+            worker.Emit(OpCodes.Brfalse, skipIfNotServerOnly);
+
+            // worker.Emit(OpCodes.Ldarg_0); // loads this. for isClient check later
+            worker.Emit(OpCodes.Call, weaverTypes.NetworkClientGetActive); // TODO isClient?
+            worker.Emit(OpCodes.Brtrue, skipIfNotServerOnly);
+
+            // Load 'this' reference (Ldarg_0)
+            worker.Emit(OpCodes.Ldarg_0);
+
+            // Load all the remaining arguments (Ldarg_1, Ldarg_2, ...)
+            for (int i = 1; i < md.Parameters.Count + 1; i++)
+                worker.Emit(OpCodes.Ldarg, i);
+
+            // Call the original function directly (UserCode_CmdTest__Int32)
+            worker.Emit(OpCodes.Call, cmd);
+            worker.Emit(OpCodes.Ret);
+
+            worker.Append(skipIfNotServerOnly);
+
+
+
             // NetworkWriter writer = new NetworkWriter();
             NetworkBehaviourProcessor.WriteGetWriter(worker, weaverTypes);
 

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

@@ -9,10 +9,15 @@ namespace Mirror.Tests.Rpcs
     class AuthorityBehaviour : NetworkBehaviour
     {
         public event Action<int> onSendInt;
+        public event Action<int, string, bool> onSendMulti;
 
         [Command]
         public void SendInt(int someInt) =>
             onSendInt?.Invoke(someInt);
+
+        [Command]
+        public void SendMulti(int someInt, string someString, bool someBool) =>
+            onSendMulti?.Invoke(someInt, someString, someBool);
     }
 
     class IgnoreAuthorityBehaviour : NetworkBehaviour
@@ -278,4 +283,48 @@ public void Command_RequiresAuthorityFalse_ForOtherObjectWithoutConnectionToServ
             Assert.That(called, Is.EqualTo(1));
         }
     }
+
+    // need server-only mode for some test
+    public class CommandTest_ServerOnly : MirrorTest
+    {
+        [SetUp]
+        public override void SetUp()
+        {
+            base.SetUp();
+            // start server without client
+            NetworkServer.Listen(1);
+        }
+
+        [TearDown]
+        public override void TearDown() => base.TearDown();
+
+        // [Command] functions should be callable on server-only for convenience.
+        // https://github.com/MirrorNetworking/Mirror/issues/3450
+        [Test]
+        public void CommandCalledWhenServerOnly()
+        {
+            // spawn
+            CreateNetworked(out _, out _, out AuthorityBehaviour serverComponent);
+
+            // set up a callback and check
+            int callCount = 0;
+            serverComponent.onSendMulti += (a, b, c) =>
+            {
+                callCount++;
+                Assert.That(a, Is.EqualTo(42));
+                Assert.That(b, Is.EqualTo("test"));
+                Assert.That(c, Is.EqualTo(true));
+            };
+
+            // call [Command] on server.
+            // test multiple parameters to ensure weaver properly injects all
+            // LdArg0,1,2, etc. instructions.
+            //
+            // this should call the function immediately,
+            // without processing messages.
+            serverComponent.SendMulti(42, "test", true);
+            // ProcessMessages();
+            Assert.That(callCount, Is.EqualTo(1));
+        }
+    }
 }