diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 4e52fa6248..96ecb432c5 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -49,6 +49,8 @@ jobs:
           workflow: build_v8.yml
           name: v8_bin
           path: unity/native_src/
+      - name: Use Xcode 12.0 for x86
+        run: sudo xcode-select -switch "/Applications/Xcode_12.app"
       - name: Build
         run: |
           cd unity/native_src
@@ -69,6 +71,8 @@ jobs:
           workflow: build_v8.yml
           name: v8_bin
           path: unity/native_src/
+      - name: Use Xcode 12.0 for x86
+        run: sudo xcode-select -switch "/Applications/Xcode_12.app"
       - name: Build
         run: |
           cd unity/native_src
diff --git a/.github/workflows/build_v8.yml b/.github/workflows/build_v8.yml
index 65872cfe04..e5742f91d7 100644
--- a/.github/workflows/build_v8.yml
+++ b/.github/workflows/build_v8.yml
@@ -107,6 +107,8 @@ jobs:
     runs-on: macos-10.15
     steps:
     - uses: actions/checkout@v2
+    - name: Use Xcode 12.0 to use SDK 10.15
+      run: sudo xcode-select -switch "/Applications/Xcode_12.app"
     - name: Run build script
       run: |
         cd $GITHUB_WORKSPACE
@@ -121,6 +123,8 @@ jobs:
     runs-on: macos-10.15
     steps:
     - uses: actions/checkout@v2
+    - name: Use Xcode 12.0 to use SDK 10.15
+      run: sudo xcode-select -switch "/Applications/Xcode_12.app"
     - name: Run build script
       run: |
         cd $GITHUB_WORKSPACE
@@ -135,6 +139,8 @@ jobs:
     runs-on: macos-10.15
     steps:
     - uses: actions/checkout@v2
+    - name: Use Xcode 12.0 to use SDK 10.15
+      run: sudo xcode-select -switch "/Applications/Xcode_12.app"
     - name: Run build script
       run: |
         cd $GITHUB_WORKSPACE
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 822ebe66c5..9715a5e6d5 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -47,6 +47,8 @@ jobs:
           workflow: build_v8.yml
           name: v8_bin
           path: unity/native_src/
+      - name: Use Xcode 12.0 for x86
+        run: sudo xcode-select -switch "/Applications/Xcode_12.app"
       - name: Build
         run: |
           cd unity/native_src
@@ -67,6 +69,8 @@ jobs:
           workflow: build_v8.yml
           name: v8_bin
           path: unity/native_src/
+      - name: Use Xcode 12.0 for x86
+        run: sudo xcode-select -switch "/Applications/Xcode_12.app"
       - name: Build
         run: |
           cd unity/native_src
diff --git a/unity/Assets/Puerts/Src/Editor/CJSImporter.cs b/unity/Assets/Puerts/Src/Editor/CJSImporter.cs
new file mode 100644
index 0000000000..ce642e96b8
--- /dev/null
+++ b/unity/Assets/Puerts/Src/Editor/CJSImporter.cs
@@ -0,0 +1,21 @@
+#if UNITY_2018_1_OR_NEWER
+using System.IO;
+using UnityEditor.Experimental.AssetImporters;
+using UnityEngine;
+ 
+[ScriptedImporter(1, "cjs")]
+public class CJSImporter : ScriptedImporter
+{
+    public override void OnImportAsset(AssetImportContext ctx)
+    {
+        TextAsset subAsset = new TextAsset(File.ReadAllText(ctx.assetPath));
+        ctx.AddObjectToAsset("text", subAsset);
+        ctx.SetMainObject(subAsset);
+
+#if ENABLE_CJS_AUTO_RELOAD
+        Puerts.JsEnv.ClearAllModuleCaches();
+#endif
+    }
+}
+
+#endif
diff --git a/unity/Assets/Puerts/Src/JsEnv.cs b/unity/Assets/Puerts/Src/JsEnv.cs
index 09cbbd469c..a8c6435ad3 100644
--- a/unity/Assets/Puerts/Src/JsEnv.cs
+++ b/unity/Assets/Puerts/Src/JsEnv.cs
@@ -172,6 +172,22 @@ public TResult Eval<TResult>(string chunk, string chunkName = "chunk")
 #endif
         }
 
+        public void ClearModuleCache ()
+        {
+            Eval("global.clearModuleCache()");
+        }
+
+        public static void ClearAllModuleCaches () 
+        {
+            lock (jsEnvs)
+            {
+                foreach (var jsEnv in jsEnvs)
+                {
+                    jsEnv.ClearModuleCache();
+                }
+            }
+        }
+
         public void AddLazyStaticWrapLoader(Type type, Func<TypeRegisterInfo> lazyStaticWrapLoader)
         {
 #if THREAD_SAFE
@@ -597,4 +613,4 @@ internal void ReleasePendingJSFunctions()
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/unity/Assets/Puerts/Src/Loader.cs b/unity/Assets/Puerts/Src/Loader.cs
index a10daaf277..6df5c275fa 100644
--- a/unity/Assets/Puerts/Src/Loader.cs
+++ b/unity/Assets/Puerts/Src/Loader.cs
@@ -30,12 +30,20 @@ public DefaultLoader(string root)
             this.root = root;
         }
 
+        private string PathToUse(string filepath)
+        {
+            return filepath.EndsWith(".cjs") ? 
+                filepath.Substring(0, filepath.Length - 4) : 
+                filepath;
+        }
+
         public bool FileExists(string filepath)
         {
 #if PUERTS_GENERAL
             return File.Exists(Path.Combine(root, filepath));
 #else
-            return UnityEngine.Resources.Load(filepath) != null;
+            string pathToUse = this.PathToUse(filepath);
+            return UnityEngine.Resources.Load(pathToUse) != null;
 #endif
         }
 
@@ -45,7 +53,8 @@ public string ReadFile(string filepath, out string debugpath)
             debugpath = Path.Combine(root, filepath);
             return File.ReadAllText(debugpath);
 #else
-            UnityEngine.TextAsset file = (UnityEngine.TextAsset)UnityEngine.Resources.Load(filepath);
+            string pathToUse = this.PathToUse(filepath);
+            UnityEngine.TextAsset file = (UnityEngine.TextAsset)UnityEngine.Resources.Load(pathToUse);
             debugpath = System.IO.Path.Combine(root, filepath);
 #if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
             debugpath = debugpath.Replace("/", "\\");
@@ -54,4 +63,4 @@ public string ReadFile(string filepath, out string debugpath)
 #endif
         }
     }
-}
\ No newline at end of file
+}
diff --git a/unity/Assets/Puerts/Src/Resources/puerts/cjsload.js.txt b/unity/Assets/Puerts/Src/Resources/puerts/cjsload.js.txt
index bcd5205fd3..3dc4421099 100644
--- a/unity/Assets/Puerts/Src/Resources/puerts/cjsload.js.txt
+++ b/unity/Assets/Puerts/Src/Resources/puerts/cjsload.js.txt
@@ -53,6 +53,7 @@ var global = global || (function () { return this; }());
             return searchModuleInDirWithExt(dir, requiredModule);
         } else {
             return searchModuleInDirWithExt(dir, requiredModule + ".js")
+                       || searchModuleInDirWithExt(dir, requiredModule + ".cjs")
                        || searchModuleInDirWithExt(dir, requiredModule + "/index.js")
                        || searchModuleInDirWithExt(dir, requiredModule + "/package.json");
         }
diff --git a/unity/Assets/Puerts/Src/Resources/puerts/modular.js.txt b/unity/Assets/Puerts/Src/Resources/puerts/modular.js.txt
index 6047567773..dc8ffa8036 100644
--- a/unity/Assets/Puerts/Src/Resources/puerts/modular.js.txt
+++ b/unity/Assets/Puerts/Src/Resources/puerts/modular.js.txt
@@ -16,8 +16,9 @@ var global = global || (function () { return this; }());
         return {fullPath: path, debugPath: debugPath, script: context}
     }
     
-    let tmpModuleStorage = [];
-    
+    let moduleCache = Object.create(null); // key to sid
+    let tmpModuleStorage = []; // sid to module
+
     function addModule(m) {
         for (var i = 0; i < tmpModuleStorage.length; i++) {
             if (!tmpModuleStorage[i]) {
@@ -32,18 +33,22 @@ var global = global || (function () { return this; }());
         return tmpModuleStorage[id];
     }
 
-    let moduleCache = Object.create(null);
     let buildinModule = Object.create(null);
     function executeModule(fullPath, script, debugPath, sid) {
         sid = (typeof sid == 'undefined') ? 0 : sid;
         let fullPathInJs = fullPath.replace(/\\/g, '\\\\');
         let fullDirInJs = (fullPath.indexOf('/') != -1) ? fullPath.substring(0, fullPath.lastIndexOf("/")) : fullPath.substring(0, fullPath.lastIndexOf("\\")).replace(/\\/g, '\\\\');
-        let executeScript = "(function() { var __filename = '"
-            + fullPathInJs + "', __dirname = '"
-            + fullDirInJs + "', module = puerts.getModuleBySID(" + sid + "), exports = module.exports; module.filename = __filename ; (function (exports, require, console, prompt) { "
-            + script + "\n})(exports, puerts.genRequire('"
-            + fullDirInJs + "'), puerts.console); return module.exports})()";
-        return puerts.evalScript(executeScript, debugPath);
+        let exports = {};
+        let module = puerts.getModuleBySID(sid);
+        module.exports = exports;
+        let wrapped = puerts.evalScript(
+            // Wrap the script in the same way NodeJS does it. It is important since IDEs (VSCode) will use this wrapper pattern
+            // to enable stepping through original source in-place.
+            "(function (exports, require, module, __filename, __dirname) { " + script + "\n});", 
+            debugPath
+        )
+        wrapped(exports, puerts.genRequire(fullDirInJs), module, fullPathInJs, fullDirInJs)
+        return module.exports;
     }
     
     function genRequire(requiringDir) {
@@ -75,6 +80,9 @@ var global = global || (function () { return this; }());
                 return m.exports;
             }
         }
+        require.clearModuleCache = () => {
+            localModuleCache = Object.create(null);
+        }
 
         return require;
     }
@@ -92,4 +100,11 @@ var global = global || (function () { return this; }());
     puerts.registerBuildinModule = registerBuildinModule;
     
     global.require = genRequire("");
-}(global));
\ No newline at end of file
+
+    function clearModuleCache () {
+        tmpModuleStorage = [];
+        moduleCache = Object.create(null);
+        global.require.clearModuleCache();
+    }
+    global.clearModuleCache = clearModuleCache;
+}(global));