LibWeb: Make Fetch::Infrastructure::{Request,Response,HeaderList} GC'd

This is the way.

On a more serious note, there's no reason to keep adding ref-counted
classes to LibWeb now that the majority of classes is GC'd - it only
adds the risk of discovering some cycle down the line, and forces us to
use handles as we can't visit().

Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.cpp

@@ -11,6 +11,8 @@
 #include <AK/GenericLexer.h>
 #include <AK/QuickSort.h>
 #include <AK/ScopeGuard.h>
+#include <LibJS/Heap/Heap.h>
+#include <LibJS/Runtime/VM.h>
 #include <LibRegex/Regex.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Headers.h>
@@ -42,6 +44,11 @@ ErrorOr<Header> Header::from_string_pair(StringView name, StringView value)
     };
 }
 
+JS::NonnullGCPtr<HeaderList> HeaderList::create(JS::VM& vm)
+{
+    return { *vm.heap().allocate_without_realm<HeaderList>() };
+}
+
 // https://fetch.spec.whatwg.org/#header-list-contains
 bool HeaderList::contains(ReadonlyBytes name) const
 {

Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.h

@@ -13,6 +13,8 @@
 #include <AK/Optional.h>
 #include <AK/String.h>
 #include <AK/Vector.h>
+#include <LibJS/Forward.h>
+#include <LibJS/Heap/Cell.h>
 #include <LibWeb/MimeSniff/MimeType.h>
 
 namespace Web::Fetch::Infrastructure {
@@ -29,13 +31,17 @@ struct Header {
 // https://fetch.spec.whatwg.org/#concept-header-list
 // A header list is a list of zero or more headers. It is initially the empty list.
 class HeaderList final
-    : public RefCounted<HeaderList>
+    : public JS::Cell
     , Vector<Header> {
+    JS_CELL(HeaderList, JS::Cell);
+
 public:
     using Vector::begin;
     using Vector::clear;
     using Vector::end;
 
+    [[nodiscard]] static JS::NonnullGCPtr<HeaderList> create(JS::VM&);
+
     [[nodiscard]] bool contains(ReadonlyBytes) const;
     [[nodiscard]] ErrorOr<Optional<ByteBuffer>> get(ReadonlyBytes) const;
     [[nodiscard]] ErrorOr<Optional<Vector<String>>> get_decode_and_split(ReadonlyBytes) const;

Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.cpp

@@ -5,18 +5,26 @@
  */
 
 #include <AK/Array.h>
+#include <LibJS/Heap/Heap.h>
+#include <LibJS/Runtime/Realm.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Requests.h>
 
 namespace Web::Fetch::Infrastructure {
 
-Request::Request()
-    : m_header_list(make_ref_counted<HeaderList>())
+Request::Request(JS::NonnullGCPtr<HeaderList> header_list)
+    : m_header_list(header_list)
 {
 }
 
-NonnullRefPtr<Request> Request::create()
+void Request::visit_edges(JS::Cell::Visitor& visitor)
 {
-    return adopt_ref(*new Request());
+    Base::visit_edges(visitor);
+    visitor.visit(m_header_list);
+}
+
+JS::NonnullGCPtr<Request> Request::create(JS::VM& vm)
+{
+    return { *vm.heap().allocate_without_realm<Request>(HeaderList::create(vm)) };
 }
 
 // https://fetch.spec.whatwg.org/#concept-request-url
@@ -181,12 +189,12 @@ ErrorOr<ByteBuffer> Request::byte_serialize_origin() const
 }
 
 // https://fetch.spec.whatwg.org/#concept-request-clone
-WebIDL::ExceptionOr<NonnullRefPtr<Request>> Request::clone() const
+WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> Request::clone(JS::VM& vm) const
 {
     // To clone a request request, run these steps:
 
     // 1. Let newRequest be a copy of request, except for its body.
-    auto new_request = Infrastructure::Request::create();
+    auto new_request = Infrastructure::Request::create(vm);
     new_request->set_method(m_method);
     new_request->set_local_urls_only(m_local_urls_only);
     for (auto const& header : *m_header_list)

Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.h

@@ -10,11 +10,12 @@
 #include <AK/Error.h>
 #include <AK/Forward.h>
 #include <AK/Optional.h>
-#include <AK/RefCounted.h>
 #include <AK/String.h>
 #include <AK/URL.h>
 #include <AK/Variant.h>
 #include <AK/Vector.h>
+#include <LibJS/Forward.h>
+#include <LibJS/Heap/Cell.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Bodies.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Headers.h>
 #include <LibWeb/HTML/Origin.h>
@@ -24,7 +25,9 @@
 namespace Web::Fetch::Infrastructure {
 
 // https://fetch.spec.whatwg.org/#concept-request
-class Request final : public RefCounted<Request> {
+class Request final : public JS::Cell {
+    JS_CELL(Request, JS::Cell);
+
 public:
     enum class CacheMode {
         Default,
@@ -156,7 +159,7 @@ public:
     using ReservedClientType = Variant<Empty, HTML::Environment*, HTML::EnvironmentSettingsObject*>;
     using WindowType = Variant<Window, HTML::EnvironmentSettingsObject*>;
 
-    static NonnullRefPtr<Request> create();
+    [[nodiscard]] static JS::NonnullGCPtr<Request> create(JS::VM&);
 
     [[nodiscard]] ReadonlyBytes method() const { return m_method; }
     void set_method(ByteBuffer method) { m_method = move(method); }
@@ -164,9 +167,8 @@ public:
     [[nodiscard]] bool local_urls_only() const { return m_local_urls_only; }
     void set_local_urls_only(bool local_urls_only) { m_local_urls_only = local_urls_only; }
 
-    [[nodiscard]] NonnullRefPtr<HeaderList> const& header_list() const { return m_header_list; }
-    [[nodiscard]] NonnullRefPtr<HeaderList>& header_list() { return m_header_list; }
-    void set_header_list(NonnullRefPtr<HeaderList> header_list) { m_header_list = move(header_list); }
+    [[nodiscard]] JS::NonnullGCPtr<HeaderList> header_list() const { return m_header_list; }
+    void set_header_list(JS::NonnullGCPtr<HeaderList> header_list) { m_header_list = header_list; }
 
     [[nodiscard]] bool unsafe_request() const { return m_unsafe_request; }
     void set_unsafe_request(bool unsafe_request) { m_unsafe_request = unsafe_request; }
@@ -294,14 +296,16 @@ public:
     [[nodiscard]] String serialize_origin() const;
     [[nodiscard]] ErrorOr<ByteBuffer> byte_serialize_origin() const;
 
-    [[nodiscard]] WebIDL::ExceptionOr<NonnullRefPtr<Request>> clone() const;
+    [[nodiscard]] WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> clone(JS::VM&) const;
 
     [[nodiscard]] ErrorOr<void> add_range_header(u64 first, Optional<u64> const& last);
 
     [[nodiscard]] bool cross_origin_embedder_policy_allows_credentials() const;
 
 private:
-    Request();
+    explicit Request(JS::NonnullGCPtr<HeaderList>);
+
+    virtual void visit_edges(JS::Cell::Visitor&) override;
 
     // https://fetch.spec.whatwg.org/#concept-request-method
     // A request has an associated method (a method). Unless stated otherwise it is `GET`.
@@ -313,7 +317,7 @@ private:
 
     // https://fetch.spec.whatwg.org/#concept-request-header-list
     // A request has an associated header list (a header list). Unless stated otherwise it is empty.
-    NonnullRefPtr<HeaderList> m_header_list;
+    JS::NonnullGCPtr<HeaderList> m_header_list;
 
     // https://fetch.spec.whatwg.org/#unsafe-request-flag
     // A request has an associated unsafe-request flag. Unless stated otherwise it is unset.

Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.cpp

@@ -4,36 +4,44 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibJS/Heap/Heap.h>
+#include <LibJS/Runtime/VM.h>
 #include <LibWeb/Bindings/MainThreadVM.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Bodies.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Responses.h>
 
 namespace Web::Fetch::Infrastructure {
 
-Response::Response()
-    : m_header_list(make_ref_counted<HeaderList>())
+Response::Response(JS::NonnullGCPtr<HeaderList> header_list)
+    : m_header_list(header_list)
 {
 }
 
-NonnullRefPtr<Response> Response::create()
+void Response::visit_edges(JS::Cell::Visitor& visitor)
 {
-    return adopt_ref(*new Response());
+    Base::visit_edges(visitor);
+    visitor.visit(m_header_list);
+}
+
+JS::NonnullGCPtr<Response> Response::create(JS::VM& vm)
+{
+    return { *vm.heap().allocate_without_realm<Response>(HeaderList::create(vm)) };
 }
 
 // https://fetch.spec.whatwg.org/#ref-for-concept-network-error%E2%91%A3
 // A network error is a response whose status is always 0, status message is always
 // the empty byte sequence, header list is always empty, and body is always null.
 
-NonnullRefPtr<Response> Response::aborted_network_error()
+JS::NonnullGCPtr<Response> Response::aborted_network_error(JS::VM& vm)
 {
-    auto response = network_error();
+    auto response = network_error(vm);
     response->set_aborted(true);
     return response;
 }
 
-NonnullRefPtr<Response> Response::network_error()
+JS::NonnullGCPtr<Response> Response::network_error(JS::VM& vm)
 {
-    auto response = Response::create();
+    auto response = Response::create(vm);
     response->set_status(0);
     response->set_type(Type::Error);
     VERIFY(!response->body().has_value());
@@ -93,29 +101,28 @@ ErrorOr<Optional<AK::URL>> Response::location_url(Optional<String> const& reques
 }
 
 // https://fetch.spec.whatwg.org/#concept-response-clone
-WebIDL::ExceptionOr<NonnullRefPtr<Response>> Response::clone() const
+WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::clone(JS::VM& vm) const
 {
     // To clone a response response, run these steps:
 
-    auto& vm = Bindings::main_thread_vm();
     auto& realm = *vm.current_realm();
 
     // 1. If response is a filtered response, then return a new identical filtered response whose internal response is a clone of response’s internal response.
     if (is<FilteredResponse>(*this)) {
-        auto internal_response = TRY(static_cast<FilteredResponse const&>(*this).internal_response()->clone());
+        auto internal_response = TRY(static_cast<FilteredResponse const&>(*this).internal_response()->clone(vm));
         if (is<BasicFilteredResponse>(*this))
-            return TRY_OR_RETURN_OOM(realm, BasicFilteredResponse::create(move(internal_response)));
+            return TRY_OR_RETURN_OOM(realm, BasicFilteredResponse::create(vm, internal_response));
         if (is<CORSFilteredResponse>(*this))
-            return TRY_OR_RETURN_OOM(realm, CORSFilteredResponse::create(move(internal_response)));
+            return TRY_OR_RETURN_OOM(realm, CORSFilteredResponse::create(vm, internal_response));
         if (is<OpaqueFilteredResponse>(*this))
-            return OpaqueFilteredResponse::create(move(internal_response));
+            return OpaqueFilteredResponse::create(vm, internal_response);
         if (is<OpaqueRedirectFilteredResponse>(*this))
-            return OpaqueRedirectFilteredResponse::create(move(internal_response));
+            return OpaqueRedirectFilteredResponse::create(vm, internal_response);
         VERIFY_NOT_REACHED();
     }
 
     // 2. Let newResponse be a copy of response, except for its body.
-    auto new_response = Infrastructure::Response::create();
+    auto new_response = Infrastructure::Response::create(vm);
     new_response->set_type(m_type);
     new_response->set_aborted(m_aborted);
     new_response->set_url_list(m_url_list);
@@ -139,8 +146,9 @@ WebIDL::ExceptionOr<NonnullRefPtr<Response>> Response::clone() const
     return new_response;
 }
 
-FilteredResponse::FilteredResponse(NonnullRefPtr<Response> internal_response)
-    : m_internal_response(move(internal_response))
+FilteredResponse::FilteredResponse(JS::NonnullGCPtr<Response> internal_response, JS::NonnullGCPtr<HeaderList> header_list)
+    : Response(header_list)
+    , m_internal_response(internal_response)
 {
 }
 
@@ -148,26 +156,38 @@ FilteredResponse::~FilteredResponse()
 {
 }
 
-ErrorOr<NonnullRefPtr<BasicFilteredResponse>> BasicFilteredResponse::create(NonnullRefPtr<Response> internal_response)
+void FilteredResponse::visit_edges(JS::Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_internal_response);
+}
+
+ErrorOr<JS::NonnullGCPtr<BasicFilteredResponse>> BasicFilteredResponse::create(JS::VM& vm, JS::NonnullGCPtr<Response> internal_response)
 {
     // A basic filtered response is a filtered response whose type is "basic" and header list excludes
     // any headers in internal response’s header list whose name is a forbidden response-header name.
-    auto header_list = make_ref_counted<HeaderList>();
+    auto header_list = HeaderList::create(vm);
     for (auto const& header : *internal_response->header_list()) {
         if (!is_forbidden_response_header_name(header.name))
             TRY(header_list->append(header));
     }
 
-    return adopt_ref(*new BasicFilteredResponse(move(internal_response), move(header_list)));
+    return { *vm.heap().allocate_without_realm<BasicFilteredResponse>(internal_response, header_list) };
 }
 
-BasicFilteredResponse::BasicFilteredResponse(NonnullRefPtr<Response> internal_response, NonnullRefPtr<HeaderList> header_list)
-    : FilteredResponse(move(internal_response))
-    , m_header_list(move(header_list))
+BasicFilteredResponse::BasicFilteredResponse(JS::NonnullGCPtr<Response> internal_response, JS::NonnullGCPtr<HeaderList> header_list)
+    : FilteredResponse(internal_response, header_list)
+    , m_header_list(header_list)
 {
 }
 
-ErrorOr<NonnullRefPtr<CORSFilteredResponse>> CORSFilteredResponse::create(NonnullRefPtr<Response> internal_response)
+void BasicFilteredResponse::visit_edges(JS::Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_header_list);
+}
+
+ErrorOr<JS::NonnullGCPtr<CORSFilteredResponse>> CORSFilteredResponse::create(JS::VM& vm, JS::NonnullGCPtr<Response> internal_response)
 {
     // A CORS filtered response is a filtered response whose type is "cors" and header list excludes
     // any headers in internal response’s header list whose name is not a CORS-safelisted response-header
@@ -176,43 +196,63 @@ ErrorOr<NonnullRefPtr<CORSFilteredResponse>> CORSFilteredResponse::create(Nonnul
     for (auto const& header_name : internal_response->cors_exposed_header_name_list())
         cors_exposed_header_name_list.append(header_name.span());
 
-    auto header_list = make_ref_counted<HeaderList>();
+    auto header_list = HeaderList::create(vm);
     for (auto const& header : *internal_response->header_list()) {
         if (is_cors_safelisted_response_header_name(header.name, cors_exposed_header_name_list))
             TRY(header_list->append(header));
     }
 
-    return adopt_ref(*new CORSFilteredResponse(move(internal_response), move(header_list)));
+    return { *vm.heap().allocate_without_realm<CORSFilteredResponse>(internal_response, header_list) };
 }
 
-CORSFilteredResponse::CORSFilteredResponse(NonnullRefPtr<Response> internal_response, NonnullRefPtr<HeaderList> header_list)
-    : FilteredResponse(move(internal_response))
-    , m_header_list(move(header_list))
+CORSFilteredResponse::CORSFilteredResponse(JS::NonnullGCPtr<Response> internal_response, JS::NonnullGCPtr<HeaderList> header_list)
+    : FilteredResponse(internal_response, header_list)
+    , m_header_list(header_list)
 {
 }
 
-NonnullRefPtr<OpaqueFilteredResponse> OpaqueFilteredResponse::create(NonnullRefPtr<Response> internal_response)
+void CORSFilteredResponse::visit_edges(JS::Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_header_list);
+}
+
+JS::NonnullGCPtr<OpaqueFilteredResponse> OpaqueFilteredResponse::create(JS::VM& vm, JS::NonnullGCPtr<Response> internal_response)
+{
+    // An opaque filtered response is a filtered response whose type is "opaque", URL list is the empty list,
+    // status is 0, status message is the empty byte sequence, header list is empty, and body is null.
+    return { *vm.heap().allocate_without_realm<OpaqueFilteredResponse>(internal_response, HeaderList::create(vm)) };
+}
+
+OpaqueFilteredResponse::OpaqueFilteredResponse(JS::NonnullGCPtr<Response> internal_response, JS::NonnullGCPtr<HeaderList> header_list)
+    : FilteredResponse(internal_response, header_list)
+    , m_header_list(header_list)
+{
+}
+
+void OpaqueFilteredResponse::visit_edges(JS::Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_header_list);
+}
+
+JS::NonnullGCPtr<OpaqueRedirectFilteredResponse> OpaqueRedirectFilteredResponse::create(JS::VM& vm, JS::NonnullGCPtr<Response> internal_response)
 {
     // An opaque-redirect filtered response is a filtered response whose type is "opaqueredirect",
     // status is 0, status message is the empty byte sequence, header list is empty, and body is null.
-    return adopt_ref(*new OpaqueFilteredResponse(move(internal_response)));
+    return { *vm.heap().allocate_without_realm<OpaqueRedirectFilteredResponse>(internal_response, HeaderList::create(vm)) };
 }
 
-OpaqueFilteredResponse::OpaqueFilteredResponse(NonnullRefPtr<Response> internal_response)
-    : FilteredResponse(move(internal_response))
-    , m_header_list(make_ref_counted<HeaderList>())
+OpaqueRedirectFilteredResponse::OpaqueRedirectFilteredResponse(JS::NonnullGCPtr<Response> internal_response, JS::NonnullGCPtr<HeaderList> header_list)
+    : FilteredResponse(internal_response, header_list)
+    , m_header_list(header_list)
 {
 }
 
-NonnullRefPtr<OpaqueRedirectFilteredResponse> OpaqueRedirectFilteredResponse::create(NonnullRefPtr<Response> internal_response)
-{
-    return adopt_ref(*new OpaqueRedirectFilteredResponse(move(internal_response)));
-}
-
-OpaqueRedirectFilteredResponse::OpaqueRedirectFilteredResponse(NonnullRefPtr<Response> internal_response)
-    : FilteredResponse(move(internal_response))
-    , m_header_list(make_ref_counted<HeaderList>())
+void OpaqueRedirectFilteredResponse::visit_edges(JS::Cell::Visitor& visitor)
 {
+    Base::visit_edges(visitor);
+    visitor.visit(m_header_list);
 }
 
 }

Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.h

@@ -10,9 +10,10 @@
 #include <AK/Error.h>
 #include <AK/Forward.h>
 #include <AK/Optional.h>
-#include <AK/RefCounted.h>
 #include <AK/URL.h>
 #include <AK/Vector.h>
+#include <LibJS/Forward.h>
+#include <LibJS/Heap/Cell.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Bodies.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Headers.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Statuses.h>
@@ -20,7 +21,9 @@
 namespace Web::Fetch::Infrastructure {
 
 // https://fetch.spec.whatwg.org/#concept-response
-class Response : public RefCounted<Response> {
+class Response : public JS::Cell {
+    JS_CELL(Response, JS::Cell);
+
 public:
     enum class CacheState {
         Local,
@@ -45,9 +48,9 @@ public:
         u64 decoded_size { 0 };
     };
 
-    [[nodiscard]] static NonnullRefPtr<Response> create();
-    [[nodiscard]] static NonnullRefPtr<Response> aborted_network_error();
-    [[nodiscard]] static NonnullRefPtr<Response> network_error();
+    [[nodiscard]] static JS::NonnullGCPtr<Response> create(JS::VM&);
+    [[nodiscard]] static JS::NonnullGCPtr<Response> aborted_network_error(JS::VM&);
+    [[nodiscard]] static JS::NonnullGCPtr<Response> network_error(JS::VM&);
 
     virtual ~Response() = default;
 
@@ -67,9 +70,8 @@ public:
     [[nodiscard]] virtual ReadonlyBytes status_message() const { return m_status_message; }
     void set_status_message(ByteBuffer status_message) { m_status_message = move(status_message); }
 
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList> const& header_list() const { return m_header_list; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList>& header_list() { return m_header_list; }
-    void set_header_list(NonnullRefPtr<HeaderList> header_list) { m_header_list = move(header_list); }
+    [[nodiscard]] virtual JS::NonnullGCPtr<HeaderList> header_list() const { return m_header_list; }
+    void set_header_list(JS::NonnullGCPtr<HeaderList> header_list) { m_header_list = header_list; }
 
     [[nodiscard]] virtual Optional<Body> const& body() const { return m_body; }
     [[nodiscard]] virtual Optional<Body>& body() { return m_body; }
@@ -99,10 +101,12 @@ public:
     [[nodiscard]] Optional<AK::URL const&> url() const;
     [[nodiscard]] ErrorOr<Optional<AK::URL>> location_url(Optional<String> const& request_fragment) const;
 
-    [[nodiscard]] WebIDL::ExceptionOr<NonnullRefPtr<Response>> clone() const;
+    [[nodiscard]] WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> clone(JS::VM&) const;
 
 protected:
-    Response();
+    explicit Response(JS::NonnullGCPtr<HeaderList>);
+
+    virtual void visit_edges(JS::Cell::Visitor&) override;
 
 private:
     // https://fetch.spec.whatwg.org/#concept-response-type
@@ -127,7 +131,7 @@ private:
 
     // https://fetch.spec.whatwg.org/#concept-response-header-list
     // A response has an associated header list (a header list). Unless stated otherwise it is empty.
-    NonnullRefPtr<HeaderList> m_header_list;
+    JS::NonnullGCPtr<HeaderList> m_header_list;
 
     // https://fetch.spec.whatwg.org/#concept-response-body
     // A response has an associated body (null or a body). Unless stated otherwise it is null.
@@ -163,8 +167,10 @@ private:
 
 // https://fetch.spec.whatwg.org/#concept-filtered-response
 class FilteredResponse : public Response {
+    JS_CELL(FilteredResponse, Response);
+
 public:
-    explicit FilteredResponse(NonnullRefPtr<Response>);
+    FilteredResponse(JS::NonnullGCPtr<Response>, JS::NonnullGCPtr<HeaderList>);
     virtual ~FilteredResponse() = 0;
 
     [[nodiscard]] virtual Type type() const override { return m_internal_response->type(); }
@@ -173,8 +179,7 @@ public:
     [[nodiscard]] virtual Vector<AK::URL>& url_list() override { return m_internal_response->url_list(); }
     [[nodiscard]] virtual Status status() const override { return m_internal_response->status(); }
     [[nodiscard]] virtual ReadonlyBytes status_message() const override { return m_internal_response->status_message(); }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList> const& header_list() const override { return m_internal_response->header_list(); }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList>& header_list() override { return m_internal_response->header_list(); }
+    [[nodiscard]] virtual JS::NonnullGCPtr<HeaderList> header_list() const override { return m_internal_response->header_list(); }
     [[nodiscard]] virtual Optional<Body> const& body() const override { return m_internal_response->body(); }
     [[nodiscard]] virtual Optional<Body>& body() override { return m_internal_response->body(); }
     [[nodiscard]] virtual Optional<CacheState> const& cache_state() const override { return m_internal_response->cache_state(); }
@@ -184,83 +189,98 @@ public:
     [[nodiscard]] virtual bool timing_allow_passed() const override { return m_internal_response->timing_allow_passed(); }
     [[nodiscard]] virtual BodyInfo const& body_info() const override { return m_internal_response->body_info(); }
 
-    [[nodiscard]] NonnullRefPtr<Response> internal_response() const { return m_internal_response; }
+    [[nodiscard]] JS::NonnullGCPtr<Response> internal_response() const { return m_internal_response; }
 
 protected:
+    virtual void visit_edges(JS::Cell::Visitor&) override;
+
+private:
     // https://fetch.spec.whatwg.org/#concept-internal-response
-    NonnullRefPtr<Response> m_internal_response;
+    JS::NonnullGCPtr<Response> m_internal_response;
 };
 
 // https://fetch.spec.whatwg.org/#concept-filtered-response-basic
 class BasicFilteredResponse final : public FilteredResponse {
+    JS_CELL(OpaqueRedirectFilteredResponse, FilteredResponse);
+
 public:
-    static ErrorOr<NonnullRefPtr<BasicFilteredResponse>> create(NonnullRefPtr<Response>);
+    [[nodiscard]] static ErrorOr<JS::NonnullGCPtr<BasicFilteredResponse>> create(JS::VM&, JS::NonnullGCPtr<Response>);
 
     [[nodiscard]] virtual Type type() const override { return Type::Basic; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList> const& header_list() const override { return m_header_list; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList>& header_list() override { return m_header_list; }
+    [[nodiscard]] virtual JS::NonnullGCPtr<HeaderList> header_list() const override { return m_header_list; }
 
 private:
-    BasicFilteredResponse(NonnullRefPtr<Response>, NonnullRefPtr<HeaderList>);
+    BasicFilteredResponse(JS::NonnullGCPtr<Response>, JS::NonnullGCPtr<HeaderList>);
 
-    NonnullRefPtr<HeaderList> m_header_list;
+    virtual void visit_edges(JS::Cell::Visitor&) override;
+
+    JS::NonnullGCPtr<HeaderList> m_header_list;
 };
 
 // https://fetch.spec.whatwg.org/#concept-filtered-response-cors
 class CORSFilteredResponse final : public FilteredResponse {
+    JS_CELL(CORSFilteredResponse, FilteredResponse);
+
 public:
-    static ErrorOr<NonnullRefPtr<CORSFilteredResponse>> create(NonnullRefPtr<Response>);
+    [[nodiscard]] static ErrorOr<JS::NonnullGCPtr<CORSFilteredResponse>> create(JS::VM&, JS::NonnullGCPtr<Response>);
 
     [[nodiscard]] virtual Type type() const override { return Type::CORS; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList> const& header_list() const override { return m_header_list; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList>& header_list() override { return m_header_list; }
+    [[nodiscard]] virtual JS::NonnullGCPtr<HeaderList> header_list() const override { return m_header_list; }
 
 private:
-    CORSFilteredResponse(NonnullRefPtr<Response>, NonnullRefPtr<HeaderList>);
+    CORSFilteredResponse(JS::NonnullGCPtr<Response>, JS::NonnullGCPtr<HeaderList>);
 
-    NonnullRefPtr<HeaderList> m_header_list;
+    virtual void visit_edges(JS::Cell::Visitor&) override;
+
+    JS::NonnullGCPtr<HeaderList> m_header_list;
 };
 
 // https://fetch.spec.whatwg.org/#concept-filtered-response-opaque
 class OpaqueFilteredResponse final : public FilteredResponse {
+    JS_CELL(OpaqueFilteredResponse, FilteredResponse);
+
 public:
-    static NonnullRefPtr<OpaqueFilteredResponse> create(NonnullRefPtr<Response>);
+    [[nodiscard]] static JS::NonnullGCPtr<OpaqueFilteredResponse> create(JS::VM&, JS::NonnullGCPtr<Response>);
 
     [[nodiscard]] virtual Type type() const override { return Type::Opaque; }
     [[nodiscard]] virtual Vector<AK::URL> const& url_list() const override { return m_url_list; }
     [[nodiscard]] virtual Vector<AK::URL>& url_list() override { return m_url_list; }
     [[nodiscard]] virtual Status status() const override { return 0; }
     [[nodiscard]] virtual ReadonlyBytes status_message() const override { return {}; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList> const& header_list() const override { return m_header_list; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList>& header_list() override { return m_header_list; }
+    [[nodiscard]] virtual JS::NonnullGCPtr<HeaderList> header_list() const override { return m_header_list; }
     [[nodiscard]] virtual Optional<Body> const& body() const override { return m_body; }
     [[nodiscard]] virtual Optional<Body>& body() override { return m_body; }
 
 private:
-    explicit OpaqueFilteredResponse(NonnullRefPtr<Response>);
+    OpaqueFilteredResponse(JS::NonnullGCPtr<Response>, JS::NonnullGCPtr<HeaderList>);
+
+    virtual void visit_edges(JS::Cell::Visitor&) override;
 
     Vector<AK::URL> m_url_list;
-    NonnullRefPtr<HeaderList> m_header_list;
+    JS::NonnullGCPtr<HeaderList> m_header_list;
     Optional<Body> m_body;
 };
 
 // https://fetch.spec.whatwg.org/#concept-filtered-response-opaque-redirect
 class OpaqueRedirectFilteredResponse final : public FilteredResponse {
+    JS_CELL(OpaqueRedirectFilteredResponse, FilteredResponse);
+
 public:
-    static NonnullRefPtr<OpaqueRedirectFilteredResponse> create(NonnullRefPtr<Response>);
+    [[nodiscard]] static JS::NonnullGCPtr<OpaqueRedirectFilteredResponse> create(JS::VM&, JS::NonnullGCPtr<Response>);
 
     [[nodiscard]] virtual Type type() const override { return Type::OpaqueRedirect; }
     [[nodiscard]] virtual Status status() const override { return 0; }
     [[nodiscard]] virtual ReadonlyBytes status_message() const override { return {}; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList> const& header_list() const override { return m_header_list; }
-    [[nodiscard]] virtual NonnullRefPtr<HeaderList>& header_list() override { return m_header_list; }
+    [[nodiscard]] virtual JS::NonnullGCPtr<HeaderList> header_list() const override { return m_header_list; }
     [[nodiscard]] virtual Optional<Body> const& body() const override { return m_body; }
     [[nodiscard]] virtual Optional<Body>& body() override { return m_body; }
 
 private:
-    explicit OpaqueRedirectFilteredResponse(NonnullRefPtr<Response>);
+    OpaqueRedirectFilteredResponse(JS::NonnullGCPtr<Response>, JS::NonnullGCPtr<HeaderList>);
 
-    NonnullRefPtr<HeaderList> m_header_list;
+    virtual void visit_edges(JS::Cell::Visitor&) override;
+
+    JS::NonnullGCPtr<HeaderList> m_header_list;
     Optional<Body> m_body;
 };