2 files changed, 18 insertions, 2 deletions
diff --git a/src/bun.js/bindings/webcore/JSWorker.cpp b/src/bun.js/bindings/webcore/JSWorker.cpp
index 4ddd97520..882c9da89 100644
--- a/src/bun.js/bindings/webcore/JSWorker.cpp
+++ b/src/bun.js/bindings/webcore/JSWorker.cpp
@@ -188,16 +188,31 @@ template<> void JSWorkerDOMConstructor::initializeProperties(VM& vm, JSDOMGlobal
     putDirect(vm, vm.propertyNames->prototype, JSWorker::prototype(vm, globalObject), JSC::PropertyAttribute::ReadOnly | JSC::PropertyAttribute::DontEnum | JSC::PropertyAttribute::DontDelete);
 }
 
+JSC_DEFINE_CUSTOM_GETTER(jsWorker_threadIdGetter, (JSGlobalObject * lexicalGlobalObject, EncodedJSValue thisValue, PropertyName))
+{
+    auto* castedThis = jsDynamicCast<JSWorker*>(JSValue::decode(thisValue));
+    if (UNLIKELY(!castedThis))
+        return JSValue::encode(jsUndefined());
+
+    // Main thread starts at 1
+    // so we say it's 0
+    //
+    // Note that we cannot use posix thread ids here because we don't know their thread id until the thread starts
+    //
+    return JSValue::encode(jsNumber(castedThis->wrapped().clientIdentifier() - 1));
+}
+
 /* Hash table for prototype */
 
 static const HashTableValue JSWorkerPrototypeTableValues[] = {
     { "constructor"_s, static_cast<unsigned>(PropertyAttribute::DontEnum), NoIntrinsic, { HashTableValue::GetterSetterType, jsWorkerConstructor, 0 } },
+    { "onerror"_s, JSC::PropertyAttribute::CustomAccessor | JSC::PropertyAttribute::DOMAttribute, NoIntrinsic, { HashTableValue::GetterSetterType, jsWorker_onerror, setJSWorker_onerror } },
     { "onmessage"_s, JSC::PropertyAttribute::CustomAccessor | JSC::PropertyAttribute::DOMAttribute, NoIntrinsic, { HashTableValue::GetterSetterType, jsWorker_onmessage, setJSWorker_onmessage } },
     { "onmessageerror"_s, JSC::PropertyAttribute::CustomAccessor | JSC::PropertyAttribute::DOMAttribute, NoIntrinsic, { HashTableValue::GetterSetterType, jsWorker_onmessageerror, setJSWorker_onmessageerror } },
-    { "onerror"_s, JSC::PropertyAttribute::CustomAccessor | JSC::PropertyAttribute::DOMAttribute, NoIntrinsic, { HashTableValue::GetterSetterType, jsWorker_onerror, setJSWorker_onerror } },
-    { "terminate"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsWorkerPrototypeFunction_terminate, 0 } },
     { "postMessage"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsWorkerPrototypeFunction_postMessage, 1 } },
     { "ref"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsWorkerPrototypeFunction_ref, 0 } },
+    { "terminate"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsWorkerPrototypeFunction_terminate, 0 } },
+    { "threadId"_s, JSC::PropertyAttribute::CustomAccessor | JSC::PropertyAttribute::DOMAttribute, NoIntrinsic, { HashTableValue::GetterSetterType, jsWorker_threadIdGetter, nullptr } },
     { "unref"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsWorkerPrototypeFunction_unref, 0 } },
 };
 
diff --git a/src/bun.js/bindings/webcore/Worker.h b/src/bun.js/bindings/webcore/Worker.h
index 76607d8da..7a6f0b032 100644
--- a/src/bun.js/bindings/webcore/Worker.h
+++ b/src/bun.js/bindings/webcore/Worker.h
@@ -96,6 +96,7 @@ public:
     void dispatchError(WTF::String message);
     void dispatchExit();
     ScriptExecutionContext* scriptExecutionContext() const final { return ContextDestructionObserver::scriptExecutionContext(); }
+    ScriptExecutionContextIdentifier clientIdentifier() const { return m_clientIdentifier; }
 
 private:
     Worker(ScriptExecutionContext&, WorkerOptions&&);