Add toStringTag value on JSG resource types

src/workerd/jsg/jsg.h

@@ -47,6 +47,7 @@ namespace workerd::jsg {
       ::workerd::jsg::JsgKind::RESOURCE; \
   using jsgSuper = jsgThis; \
   using jsgThis = Type; \
+  inline kj::StringPtr jsgGetName() const { return #Type##_kjc; } \
   inline kj::StringPtr jsgGetMemoryName() const override { return #Type##_kjc; } \
   inline size_t jsgGetMemorySelfSize() const override { return sizeof(Type); } \
   inline void jsgGetMemoryInfo(jsg::MemoryTracker& tracker) const override { \

src/workerd/jsg/resource.h

@@ -679,6 +679,9 @@ struct ResourceTypeBuilder {
     inspectProperties = v8::ObjectTemplate::New(isolate);
     prototype->Set(symbol, inspectProperties, static_cast<v8::PropertyAttribute>(
       v8::PropertyAttribute::ReadOnly | v8::PropertyAttribute::DontEnum));
+
+    auto toStringTagSymbol = v8::Symbol::GetToStringTag(isolate);
+    prototype->Set(toStringTagSymbol, v8StrIntern(isolate, typeWrapper.jsgGetName()), 0);
   }
 
   template <typename Type, typename GetNamedMethod, GetNamedMethod getNamedMethod>

src/workerd/jsg/setup.h

@@ -472,6 +472,7 @@ class Isolate: public IsolateBase {
   class Type##_TypeWrapper final: public Type##_TypeWrapperBase { \
   public: \
     using Type##_TypeWrapperBase::TypeWrapper; \
+    kj::StringPtr jsgGetName() const { return #Type##_kjc; } \
   }; \
   class Type final: public ::workerd::jsg::Isolate<Type##_TypeWrapper> { \
   public: \

src/workerd/jsg/wrappable.h

@@ -118,7 +118,7 @@ class Wrappable: public kj::Refcounted {
   virtual void jsgVisitForGc(GcVisitor& visitor);
 
   virtual kj::StringPtr jsgGetMemoryName() const {
-    KJ_UNIMPLEMENTED("jsgGetTypeName is not implemented. "
+    KJ_UNIMPLEMENTED("jsgGetMemoryName is not implemented. "
                      "It must be overridden by subclasses");
   }