Merge pull request #1291 from Scriptwonder/fix/1276-deferred-reload-compiling

fix: trust the pipeline flag when a domain reload is deferred (#1276)

Author: Scriptwonder

MCPForUnity/Editor/Services/EditorStateCache.cs

@@ -260,8 +260,8 @@ static EditorStateCache()
                 EditorApplication.playModeStateChanged += _ => ForceUpdate("playmode");
 
                 // Tracks whether an assembly compilation is actually running, for
-                // GetActualIsCompiling's Play-mode check. Statics reset on domain reload
-                // and this [InitializeOnLoad] ctor re-subscribes, so the flag is per-domain.
+                // GetActualIsCompiling. Statics reset on domain reload and this
+                // [InitializeOnLoad] ctor re-subscribes, so the flag is per-domain.
                 UnityEditor.Compilation.CompilationPipeline.compilationStarted += _ => _pipelineCompilationRunning = true;
                 UnityEditor.Compilation.CompilationPipeline.compilationFinished += _ => _pipelineCompilationRunning = false;
 
@@ -288,7 +288,7 @@ private static void OnUpdate()
         {
             // Throttle to reduce overhead while keeping the snapshot fresh enough for polling clients.
             double now = EditorApplication.timeSinceStartup;
-            // Use GetActualIsCompiling() to avoid Play mode false positives (issue #582)
+            // Use GetActualIsCompiling() to avoid isCompiling false positives (issues #549, #1276)
             bool isCompiling = GetActualIsCompiling();
 
             // Check for compilation edge transitions (always update on these)
@@ -543,10 +543,12 @@ public static JObject GetSnapshot()
         private static bool _pipelineCompilationRunning;
 
         /// <summary>
-        /// Returns the actual compilation state, working around a known Unity quirk where
-        /// EditorApplication.isCompiling can return false positives in Play mode (e.g. a
-        /// recompile deferred by Recompile-After-Finished-Playing keeps it true for the
-        /// whole play session). See: https://github.com/CoplayDev/unity-mcp/issues/549
+        /// Returns the actual compilation state, working around known Unity quirks where
+        /// EditorApplication.isCompiling reports false positives while no compilation is
+        /// running: a recompile deferred by Recompile-After-Finished-Playing keeps it true
+        /// for the whole play session (issue #549), and a project holding
+        /// EditorApplication.LockReloadAssemblies keeps it true until the lock is released
+        /// (issue #1276). In both cases the event-tracked pipeline flag is authoritative.
         /// </summary>
         internal static bool GetActualIsCompiling()
         {
@@ -556,16 +558,9 @@ internal static bool GetActualIsCompiling()
                 return false;
             }
 
-            // In Play mode, trust the event-tracked pipeline state instead: a deferred
-            // recompile keeps EditorApplication.isCompiling true without any compilation
-            // actually running.
-            if (EditorApplication.isPlaying)
-            {
-                return _pipelineCompilationRunning;
-            }
-
-            // Outside Play mode the raw signal is reliable.
-            return true;
+            // Otherwise trust the event-tracked pipeline state: isCompiling stays true for as
+            // long as an assembly reload is deferred, with no compilation actually running.
+            return _pipelineCompilationRunning;
         }
     }
 }

MCPForUnity/Editor/Services/StdioBridgeReloadHandler.cs

@@ -114,14 +114,8 @@ private static void OnAfterAssemblyReload()
             }
 
             // If the editor is not compiling, attempt an immediate restart without relying on editor focus.
-            bool isCompiling = EditorApplication.isCompiling;
-            try
-            {
-                var pipeline = Type.GetType("UnityEditor.Compilation.CompilationPipeline, UnityEditor");
-                var prop = pipeline?.GetProperty("isCompiling", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static);
-                if (prop != null) isCompiling |= (bool)prop.GetValue(null);
-            }
-            catch { }
+            // Routed through EditorStateCache so a deferred reload (issue #1276) does not block resume.
+            bool isCompiling = EditorStateCache.GetActualIsCompiling();
 
             if (!isCompiling)
             {

MCPForUnity/Editor/Services/TestJobManager.cs

@@ -502,7 +502,7 @@ internal static TestJob GetJob(string jobId)
                 {
                     long now = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
                     long initTimeout = job.InitTimeoutMs > 0 ? job.InitTimeoutMs : DefaultInitializationTimeoutMs;
-                    if (!EditorApplication.isCompiling && !EditorApplication.isUpdating && now - job.StartedUnixMs > initTimeout)
+                    if (!EditorStateCache.GetActualIsCompiling() && !EditorApplication.isUpdating && now - job.StartedUnixMs > initTimeout)
                     {
                         McpLog.Warn($"[TestJobManager] Job {jobId} failed to initialize within {initTimeout}ms, auto-failing");
                         job.Status = TestJobStatus.Failed;
@@ -589,7 +589,7 @@ private static string GetBlockedReason(TestJob job)
                 return "editor_unfocused";
             }
 
-            if (EditorApplication.isCompiling)
+            if (EditorStateCache.GetActualIsCompiling())
             {
                 return "compiling";
             }

MCPForUnity/Editor/Services/Transport/Transports/StdioBridgeHost.cs

@@ -237,24 +237,10 @@ private static void EnsureStartedOnEditorIdle()
             }
         }
 
-        private static bool IsCompiling()
-        {
-            if (EditorApplication.isCompiling)
-            {
-                return true;
-            }
-            try
-            {
-                Type pipeline = Type.GetType("UnityEditor.Compilation.CompilationPipeline, UnityEditor");
-                var prop = pipeline?.GetProperty("isCompiling", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static);
-                if (prop != null)
-                {
-                    return (bool)prop.GetValue(null);
-                }
-            }
-            catch { }
-            return false;
-        }
+        // Routed through EditorStateCache so a deferred domain reload (issue #1276) does not
+        // pin the bridge off: raw EditorApplication.isCompiling stays true for as long as the
+        // reload is held, and this gates bridge startup.
+        private static bool IsCompiling() => EditorStateCache.GetActualIsCompiling();
 
         public static void Start()
         {

MCPForUnity/Editor/Tools/ManageScriptableObject.cs

@@ -4,6 +4,7 @@
 using System.Linq;
 using System.Text.RegularExpressions;
 using MCPForUnity.Editor.Helpers;
+using MCPForUnity.Editor.Services;
 using Newtonsoft.Json.Linq;
 using UnityEditor;
 using UnityEngine;
@@ -44,7 +45,7 @@ public static object HandleCommand(JObject @params)
                 return new ErrorResponse(CodeInvalidParams);
             }
 
-            if (EditorApplication.isCompiling || EditorApplication.isUpdating)
+            if (EditorStateCache.GetActualIsCompiling() || EditorApplication.isUpdating)
             {
                 // Unity is transient; treat as retryable on the client side.
                 return new ErrorResponse(CodeCompilingOrReloading, new { hint = "retry" });

MCPForUnity/Editor/Tools/RefreshUnity.cs

@@ -109,7 +109,7 @@ await WaitForUnityReadyAsync(
                 }
             }
 
-            string resultingState = EditorApplication.isCompiling
+            string resultingState = EditorStateCache.GetActualIsCompiling()
                 ? "compiling"
                 : (EditorApplication.isUpdating ? "asset_import" : "idle");
 
@@ -146,7 +146,7 @@ void Tick()
                         return;
                     }
 
-                    if (!EditorApplication.isCompiling
+                    if (!EditorStateCache.GetActualIsCompiling()
                         && !EditorApplication.isUpdating
                         && !TestRunStatus.IsRunning
                         && !EditorApplication.isPlayingOrWillChangePlaymode)

MCPForUnity/Editor/Tools/UnityReflect.cs

@@ -6,6 +6,7 @@
 using System.Runtime.CompilerServices;
 using System.Text.RegularExpressions;
 using MCPForUnity.Editor.Helpers;
+using MCPForUnity.Editor.Services;
 using MCPForUnity.Runtime.Helpers;
 using Newtonsoft.Json.Linq;
 using UnityEditor;
@@ -99,7 +100,7 @@ private static Dictionary<string, Type[]> GetAssemblyTypeCache()
 
         public static object HandleCommand(JObject @params)
         {
-            if (EditorApplication.isCompiling)
+            if (EditorStateCache.GetActualIsCompiling())
                 return new ErrorResponse("Cannot reflect while Unity is compiling. Wait for domain reload to complete.");
 
             if (@params == null)