Support a default object in CommonJS wrapper

Fixes #1284

Related to #1285

src/bun.js/builtins/cpp/ImportMetaObjectBuiltins.cpp

@@ -168,7 +168,7 @@ const char* const s_importMetaObjectLoadCJS2ESMCode =
 const JSC::ConstructAbility s_importMetaObjectRequireESMCodeConstructAbility = JSC::ConstructAbility::CannotConstruct;
 const JSC::ConstructorKind s_importMetaObjectRequireESMCodeConstructorKind = JSC::ConstructorKind::None;
 const JSC::ImplementationVisibility s_importMetaObjectRequireESMCodeImplementationVisibility = JSC::ImplementationVisibility::Public;
-const int s_importMetaObjectRequireESMCodeLength = 561;
+const int s_importMetaObjectRequireESMCodeLength = 626;
 static const JSC::Intrinsic s_importMetaObjectRequireESMCodeIntrinsic = JSC::NoIntrinsic;
 const char* const s_importMetaObjectRequireESMCode =
     "(function (resolved) {\n" \
@@ -184,9 +184,13 @@ const char* const s_importMetaObjectRequireESMCode =
     "  }\n" \
     "  var exports = @Loader.getModuleNamespaceObject(entry.module);\n" \
     "  var commonJS = exports.default;\n" \
-    "  if (commonJS && @isCallable(commonJS) && @commonJSSymbol in commonJS) {\n" \
+    "  var cjs = commonJS && commonJS[@commonJSSymbol];\n" \
+    "  if (cjs === 0) {\n" \
+    "    return commonJS;\n" \
+    "  } else if (cjs && @isCallable(commonJS)) {\n" \
     "    return commonJS();\n" \
     "  }\n" \
+    "  \n" \
     "  return exports;\n" \
     "})\n" \
 ;

src/bun.js/builtins/js/ImportMetaObject.js

@@ -148,9 +148,13 @@ function requireESM(resolved) {
   }
   var exports = @Loader.getModuleNamespaceObject(entry.module);
   var commonJS = exports.default;
-  if (commonJS && @isCallable(commonJS) && @commonJSSymbol in commonJS) {
+  var cjs = commonJS && commonJS[@commonJSSymbol];
+  if (cjs === 0) {
+    return commonJS;
+  } else if (cjs && @isCallable(commonJS)) {
     return commonJS();
   }
+
   return exports;
 }
 

src/bun.js/modules/EventsModule.h

@@ -3,6 +3,7 @@
 
 namespace Zig {
 using namespace WebCore;
+
 inline void generateEventsSourceCode(JSC::JSGlobalObject *lexicalGlobalObject,
                                      JSC::Identifier moduleKey,
                                      Vector<JSC::Identifier, 4> &exportNames,
@@ -31,6 +32,23 @@ inline void generateEventsSourceCode(JSC::JSGlobalObject *lexicalGlobalObject,
   exportValues.append(JSC::JSFunction::create(
       vm, lexicalGlobalObject, 0, MAKE_STATIC_STRING_IMPL("on"),
       Events_functionOn, ImplementationVisibility::Public));
+
+  JSFunction *eventEmitterModuleCJS =
+      jsCast<JSFunction *>(WebCore::JSEventEmitter::getConstructor(
+          vm, reinterpret_cast<Zig::GlobalObject *>(globalObject)));
+
+  eventEmitterModuleCJS->putDirect(
+      vm,
+      PropertyName(
+          Identifier::fromUid(vm.symbolRegistry().symbolForKey("CommonJS"_s))),
+      jsNumber(0), 0);
+
+  for (size_t i = 0; i < exportNames.size(); i++) {
+    eventEmitterModuleCJS->putDirect(vm, exportNames[i], exportValues.at(i), 0);
+  }
+
+  exportNames.append(JSC::Identifier::fromString(vm, "default"_s));
+  exportValues.append(eventEmitterModuleCJS);
 }
 
 } // namespace Zig

src/runtime.js

@@ -128,7 +128,7 @@ export var __commonJS = (cb, name) => {
     return mod_exports;
   };
 
-  requireFunction[cjsRequireSymbol] = true;
+  requireFunction[cjsRequireSymbol] = 1;
   return requireFunction;
 };
 

test/bun.js/node-builtins.test.js

@@ -1,16 +1,18 @@
 import { describe, it, expect } from "bun:test";
 
 import { EventEmitter } from "events";
-
+var emitters = [EventEmitter, require("events")];
 describe("EventEmitter", () => {
   it("should emit events", () => {
-    const emitter = new EventEmitter();
-    var called = false;
-    const listener = () => {
-      called = true;
-    };
-    emitter.on("test", listener);
-    emitter.emit("test");
-    expect(called).toBe(true);
+    for (let Emitter of emitters) {
+      const emitter = new Emitter();
+      var called = false;
+      const listener = () => {
+        called = true;
+      };
+      emitter.on("test", listener);
+      emitter.emit("test");
+      expect(called).toBe(true);
+    }
   });
 });