"Fix" monkey-patching EventEmitter prototype

4 files changed, 73 insertions, 35 deletions

diff --git a/src/bun.js/bindings/webcore/JSEventEmitter.cpp b/src/bun.js/bindings/webcore/JSEventEmitter.cpp
index bcd0d9a50..8ef858166 100644
--- a/src/bun.js/bindings/webcore/JSEventEmitter.cpp
+++ b/src/bun.js/bindings/webcore/JSEventEmitter.cpp
@@ -517,16 +517,16 @@ JSC_DEFINE_HOST_FUNCTION(Events_functionGetEventListeners,
     UNUSED_PARAM(callFrame);
     if (UNLIKELY(callFrame->argumentCount() < 2))
         return throwVMError(lexicalGlobalObject, throwScope, createNotEnoughArgumentsError(lexicalGlobalObject));
-    auto* argument0 = JSC::jsDynamicCast<JSEventEmitter*>(callFrame->uncheckedArgument(0));
+    auto argument0 = jsEventEmitterCast(vm, lexicalGlobalObject, callFrame->uncheckedArgument(0));
     if (UNLIKELY(!argument0)) {
         throwException(lexicalGlobalObject, throwScope, createError(lexicalGlobalObject, "Expected EventEmitter"_s));
         return JSValue::encode(JSC::jsUndefined());
     }
-    auto* impl = JSEventEmitter::toWrapped(vm, argument0);
+    auto& impl = argument0->wrapped();
     auto eventType = callFrame->uncheckedArgument(1).toPropertyKey(lexicalGlobalObject);
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
     JSC::MarkedArgumentBuffer args;
-    for (auto* listener : impl->getListeners(eventType)) {
+    for (auto* listener : impl.getListeners(eventType)) {
         args.append(listener);
     }
     RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(JSC::constructArray(lexicalGlobalObject, static_cast<JSC::ArrayAllocationProfile*>(nullptr), WTFMove(args))));
@@ -541,15 +541,15 @@ JSC_DEFINE_HOST_FUNCTION(Events_functionListenerCount,
     UNUSED_PARAM(callFrame);
     if (UNLIKELY(callFrame->argumentCount() < 2))
         return throwVMError(lexicalGlobalObject, throwScope, createNotEnoughArgumentsError(lexicalGlobalObject));
-    auto* argument0 = JSC::jsDynamicCast<JSEventEmitter*>(callFrame->uncheckedArgument(0));
+    auto argument0 = jsEventEmitterCast(vm, lexicalGlobalObject, callFrame->uncheckedArgument(0));
     if (UNLIKELY(!argument0)) {
         throwException(lexicalGlobalObject, throwScope, createError(lexicalGlobalObject, "Expected EventEmitter"_s));
         return JSValue::encode(JSC::jsUndefined());
     }
-    auto* impl = JSEventEmitter::toWrapped(vm, argument0);
+    auto& impl = argument0->wrapped();
     auto eventType = callFrame->uncheckedArgument(1).toPropertyKey(lexicalGlobalObject);
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
-    RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(JSC::jsNumber(impl->listenerCount(eventType))));
+    RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(JSC::jsNumber(impl.listenerCount(eventType))));
 }
 
 JSC_DEFINE_HOST_FUNCTION(Events_functionOnce,
@@ -562,18 +562,18 @@ JSC_DEFINE_HOST_FUNCTION(Events_functionOnce,
 
     if (UNLIKELY(callFrame->argumentCount() < 3))
         return throwVMError(lexicalGlobalObject, throwScope, createNotEnoughArgumentsError(lexicalGlobalObject));
-    auto* argument0 = JSC::jsDynamicCast<JSEventEmitter*>(callFrame->uncheckedArgument(0));
+    auto argument0 = jsEventEmitterCastFast(vm, lexicalGlobalObject, callFrame->uncheckedArgument(0));
     if (UNLIKELY(!argument0)) {
         throwException(lexicalGlobalObject, throwScope, createError(lexicalGlobalObject, "Expected EventEmitter"_s));
         return JSValue::encode(JSC::jsUndefined());
     }
-    auto* impl = JSEventEmitter::toWrapped(vm, argument0);
+    auto& impl = argument0->wrapped();
     auto eventType = callFrame->uncheckedArgument(1).toPropertyKey(lexicalGlobalObject);
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
     EnsureStillAliveScope argument2 = callFrame->uncheckedArgument(2);
     auto listener = convert<IDLNullable<IDLEventListener<JSEventListener>>>(*lexicalGlobalObject, argument2.value(), *argument0, [](JSC::JSGlobalObject& lexicalGlobalObject, JSC::ThrowScope& scope) { throwArgumentMustBeObjectError(lexicalGlobalObject, scope, 2, "listener", "EventEmitter", "removeListener"); });
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
-    auto result = JSValue::encode(toJS<IDLUndefined>(*lexicalGlobalObject, throwScope, [&]() -> decltype(auto) { return impl->addListenerForBindings(WTFMove(eventType), WTFMove(listener), true, false); }));
+    auto result = JSValue::encode(toJS<IDLUndefined>(*lexicalGlobalObject, throwScope, [&]() -> decltype(auto) { return impl.addListenerForBindings(WTFMove(eventType), WTFMove(listener), true, false); }));
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
     vm.writeBarrier(argument0, argument2.value());
     return result;
@@ -589,18 +589,18 @@ JSC_DEFINE_HOST_FUNCTION(Events_functionOn,
 
     if (UNLIKELY(callFrame->argumentCount() < 3))
         return throwVMError(lexicalGlobalObject, throwScope, createNotEnoughArgumentsError(lexicalGlobalObject));
-    auto* argument0 = JSC::jsDynamicCast<JSEventEmitter*>(callFrame->uncheckedArgument(0));
+    auto argument0 = jsEventEmitterCastFast(vm, lexicalGlobalObject, callFrame->uncheckedArgument(0));
     if (UNLIKELY(!argument0)) {
         throwException(lexicalGlobalObject, throwScope, createError(lexicalGlobalObject, "Expected EventEmitter"_s));
         return JSValue::encode(JSC::jsUndefined());
     }
-    auto* impl = JSEventEmitter::toWrapped(vm, argument0);
+    auto& impl = argument0->wrapped();
     auto eventType = callFrame->uncheckedArgument(1).toPropertyKey(lexicalGlobalObject);
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
     EnsureStillAliveScope argument2 = callFrame->uncheckedArgument(2);
     auto listener = convert<IDLNullable<IDLEventListener<JSEventListener>>>(*lexicalGlobalObject, argument2.value(), *argument0, [](JSC::JSGlobalObject& lexicalGlobalObject, JSC::ThrowScope& scope) { throwArgumentMustBeObjectError(lexicalGlobalObject, scope, 2, "listener", "EventEmitter", "removeListener"); });
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
-    auto result = JSValue::encode(toJS<IDLUndefined>(*lexicalGlobalObject, throwScope, [&]() -> decltype(auto) { return impl->addListenerForBindings(WTFMove(eventType), WTFMove(listener), false, false); }));
+    auto result = JSValue::encode(toJS<IDLUndefined>(*lexicalGlobalObject, throwScope, [&]() -> decltype(auto) { return impl.addListenerForBindings(WTFMove(eventType), WTFMove(listener), false, false); }));
     RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
     vm.writeBarrier(argument0, argument2.value());
     return result;
diff --git a/src/bun.js/bindings/webcore/JSEventEmitterCustom.cpp b/src/bun.js/bindings/webcore/JSEventEmitterCustom.cpp
index 64ae6e1c8..15284fe6c 100644
--- a/src/bun.js/bindings/webcore/JSEventEmitterCustom.cpp
+++ b/src/bun.js/bindings/webcore/JSEventEmitterCustom.cpp
@@ -4,6 +4,17 @@
 #include "EventEmitter.h"
 #include "JSDOMWrapperCache.h"
 #include "JSEventListener.h"
+#include "ZigGlobalObject.h"
+
+#include "JSDOMConstructor.h"
+#include "JSDOMConvertBase.h"
+#include "JSDOMConvertBoolean.h"
+#include "JSDOMConvertDictionary.h"
+#include "JSDOMConvertInterface.h"
+#include "JSDOMConvertNullable.h"
+#include "JSDOMConvertNumbers.h"
+#include "JSDOMConvertSequences.h"
+#include "JSDOMConvertStrings.h"
 
 namespace WebCore {
 using namespace JSC;
@@ -22,25 +33,51 @@ EventEmitter* JSEventEmitter::toWrapped(VM& vm, JSValue value)
 
 std::unique_ptr<JSEventEmitterWrapper> jsEventEmitterCast(VM& vm, JSC::JSGlobalObject* lexicalGlobalObject, JSValue thisValue)
 {
-    if (auto* target = jsDynamicCast<JSEventEmitter*>(thisValue))
-        return makeUnique<JSEventEmitterWrapper>(target->wrapped(), *target);
-    if (auto* object = jsDynamicCast<JSNonFinalObject*>(thisValue)) {
-        // need to create a EventEmitter for Object.
-        // use `mapPrivateName` as it is not occupied.
-        auto emitterTag = WebCore::clientData(vm)->builtinNames().mapPrivateName();
-        JSC::JSValue value = object->getDirect(vm, emitterTag);
-        if (!value) {
-            Zig::GlobalObject* globalObject = reinterpret_cast<Zig::GlobalObject*>(lexicalGlobalObject);
-            value = WebCore::toJSNewlyCreated(lexicalGlobalObject, globalObject, EventEmitter::create(*globalObject->scriptExecutionContext()));
-            object->putDirect(vm, emitterTag, value);
-        }
-        auto* target = jsCast<JSEventEmitter*>(value);
-        return makeUnique<JSEventEmitterWrapper>(target->wrapped(), *target);
+    if (auto* emitter = jsEventEmitterCastFast(vm, lexicalGlobalObject, thisValue)) {
+        return std::make_unique<JSEventEmitterWrapper>(emitter->wrapped(), asObject(thisValue));
     }
 
     return nullptr;
 }
 
+JSEventEmitter* jsEventEmitterCastFast(VM& vm, JSC::JSGlobalObject* lexicalGlobalObject, JSValue thisValue)
+{
+    if (thisValue.inherits<JSEventEmitter>())
+        return jsCast<JSEventEmitter*>(asObject(thisValue));
+
+    if (UNLIKELY(thisValue.isUndefinedOrNull() || !thisValue.isObject())) {
+        return nullptr;
+    }
+
+    auto* thisObject = asObject(thisValue);
+
+    auto clientData = WebCore::clientData(vm);
+    auto name = clientData->builtinNames()._eventsPublicName();
+    if (JSValue _events = thisObject->getIfPropertyExists(lexicalGlobalObject, name)) {
+        if (!_events.isUndefinedOrNull() && _events.inherits<JSEventEmitter>()) {
+            return jsCast<JSEventEmitter*>(asObject(_events));
+        }
+    }
+
+    auto scope = DECLARE_CATCH_SCOPE(vm);
+    auto* globalObject = reinterpret_cast<Zig::GlobalObject*>(lexicalGlobalObject);
+    auto impl = EventEmitter::create(*globalObject->scriptExecutionContext());
+
+    auto throwScope = DECLARE_THROW_SCOPE(vm);
+    auto result = toJSNewlyCreated<IDLInterface<EventEmitter>>(*lexicalGlobalObject, *globalObject, throwScope, WTFMove(impl));
+
+    thisObject->putDirect(vm, name, result, 0);
+
+    if (scope.exception()) {
+        scope.clearException();
+        return nullptr;
+    }
+
+    RETURN_IF_EXCEPTION(throwScope, nullptr);
+
+    return jsCast<JSEventEmitter*>(asObject(result));
+}
+
 template<typename Visitor>
 void JSEventEmitter::visitAdditionalChildren(Visitor& visitor)
 {
diff --git a/src/bun.js/bindings/webcore/JSEventEmitterCustom.h b/src/bun.js/bindings/webcore/JSEventEmitterCustom.h
index ed2ffed0c..b75ee5774 100644
--- a/src/bun.js/bindings/webcore/JSEventEmitterCustom.h
+++ b/src/bun.js/bindings/webcore/JSEventEmitterCustom.h
@@ -10,7 +10,7 @@ class JSEventEmitterWrapper {
     WTF_MAKE_FAST_ALLOCATED;
 
 public:
-    JSEventEmitterWrapper(EventEmitter& wrapped, JSC::JSObject& wrapper)
+    JSEventEmitterWrapper(EventEmitter& wrapped, JSC::JSObject* wrapper)
         : m_wrapped(wrapped)
         , m_wrapper(wrapper)
     {
@@ -18,18 +18,20 @@ public:
 
     EventEmitter& wrapped() { return m_wrapped; }
 
-    operator JSC::JSObject&() { return m_wrapper; }
+    operator JSC::JSObject&() { return *m_wrapper; }
 
 private:
     EventEmitter& m_wrapped;
-    JSC::JSObject& m_wrapper;
+    JSC::JSObject* m_wrapper;
 };
 
 std::unique_ptr<JSEventEmitterWrapper> jsEventEmitterCast(JSC::VM&, JSC::JSGlobalObject*, JSC::JSValue thisValue);
+JSEventEmitter* jsEventEmitterCastFast(VM& vm, JSC::JSGlobalObject* lexicalGlobalObject, JSValue thisValue);
 
-template<> class IDLOperation<JSEventEmitter> {
+template<>
+class IDLOperation<JSEventEmitter> {
 public:
-    using ClassParameter = JSEventEmitterWrapper*;
+    using ClassParameter = JSEventEmitter*;
     using Operation = JSC::EncodedJSValue(JSC::JSGlobalObject*, JSC::CallFrame*, ClassParameter);
 
     template<Operation operation, CastedThisErrorBehavior = CastedThisErrorBehavior::Throw>
@@ -39,13 +41,11 @@ public:
         auto throwScope = DECLARE_THROW_SCOPE(vm);
 
         auto thisValue = callFrame.thisValue().toThis(&lexicalGlobalObject, JSC::ECMAMode::strict());
-        auto thisObject = jsEventEmitterCast(vm, &lexicalGlobalObject, thisValue.isUndefinedOrNull() ? JSC::JSValue(&lexicalGlobalObject) : thisValue);
+        auto* thisObject = jsEventEmitterCastFast(vm, &lexicalGlobalObject, thisValue);
         if (UNLIKELY(!thisObject))
             return throwThisTypeError(lexicalGlobalObject, throwScope, "EventEmitter", operationName);
 
-        auto& wrapped = thisObject->wrapped();
-
-        RELEASE_AND_RETURN(throwScope, (operation(&lexicalGlobalObject, &callFrame, thisObject.get())));
+        RELEASE_AND_RETURN(throwScope, (operation(&lexicalGlobalObject, &callFrame, thisObject)));
     }
 };
 
diff --git a/src/bun.js/builtins/BunBuiltinNames.h b/src/bun.js/builtins/BunBuiltinNames.h
index 5977f05dd..ba4e659ec 100644
--- a/src/bun.js/builtins/BunBuiltinNames.h
+++ b/src/bun.js/builtins/BunBuiltinNames.h
@@ -247,6 +247,7 @@ using namespace JSC;
     macro(writer) \
     macro(writing) \
     macro(written) \
+    macro(_events) \
     BUN_ADDITIONAL_PRIVATE_IDENTIFIERS(macro) \
 
 class BunBuiltinNames {