LibWeb: Implement the LegacyUnforgeable attribute

This fixes the frame-ancestors WPT tests from crashing when an iframe
is blocked from loading. This is because it would get an undefined
location.href from the cross-origin iframe, which causes a crash as it
expects it to be there.

Libraries/LibIDL/IDLParser.cpp

@@ -504,7 +504,7 @@ void Parser::parse_stringifier(HashMap<ByteString, ByteString>& extended_attribu
     interface.has_stringifier = true;
     if (lexer.next_is("attribute"sv) || lexer.next_is("inherit"sv) || lexer.next_is("readonly"sv)) {
         parse_attribute(extended_attributes, interface);
-        interface.stringifier_attribute = interface.attributes.last().name;
+        interface.stringifier_attribute = interface.attributes.last();
     } else {
         assert_specific(';');
     }

Libraries/LibIDL/Types.h

@@ -280,7 +280,7 @@ public:
     Vector<Function> functions;
     Vector<Function> static_functions;
     bool has_stringifier { false };
-    Optional<ByteString> stringifier_attribute;
+    Optional<Attribute> stringifier_attribute;
     bool has_unscopable_member { false };
 
     Optional<NonnullRefPtr<Type const>> value_iterator_type;

Libraries/LibWeb/DOM/Document.cpp

@@ -483,6 +483,7 @@ void Document::initialize(JS::Realm& realm)
 {
     Base::initialize(realm);
     WEB_SET_PROTOTYPE_FOR_INTERFACE(Document);
+    Bindings::DocumentPrototype::define_unforgeable_attributes(realm, *this);
 
     m_selection = realm.create<Selection::Selection>(realm, *this);
 

Libraries/LibWeb/DOM/Event.cpp

@@ -57,6 +57,7 @@ void Event::initialize(JS::Realm& realm)
 {
     Base::initialize(realm);
     WEB_SET_PROTOTYPE_FOR_INTERFACE(Event);
+    Bindings::EventPrototype::define_unforgeable_attributes(realm, *this);
 }
 
 void Event::visit_edges(Visitor& visitor)

Libraries/LibWeb/HTML/Location.cpp

@@ -43,6 +43,7 @@ void Location::initialize(JS::Realm& realm)
 {
     Base::initialize(realm);
     WEB_SET_PROTOTYPE_FOR_INTERFACE(Location);
+    Bindings::LocationPrototype::define_unforgeable_attributes(realm, *this);
 
     auto& vm = this->vm();
 

Libraries/LibWeb/HTML/Window.cpp

@@ -731,6 +731,7 @@ WebIDL::ExceptionOr<void> Window::initialize_web_interfaces(Badge<WindowEnvironm
     WEB_SET_PROTOTYPE_FOR_INTERFACE(Window);
 
     Bindings::WindowGlobalMixin::initialize(realm, *this);
+    Bindings::WindowGlobalMixin::define_unforgeable_attributes(realm, *this);
     WindowOrWorkerGlobalScopeMixin::initialize(realm);
 
     if (s_internals_object_exposed)

Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp

@@ -3338,8 +3338,12 @@ void @named_properties_class@::visit_edges(Visitor& visitor)
 )~~~");
 }
 
-// https://webidl.spec.whatwg.org/#interface-prototype-object
-static void generate_prototype_or_global_mixin_definitions(IDL::Interface const& interface, StringBuilder& builder)
+enum class GenerateUnforgeables {
+    No,
+    Yes,
+};
+
+static void generate_prototype_or_global_mixin_initialization(IDL::Interface const& interface, StringBuilder& builder, GenerateUnforgeables generate_unforgeables)
 {
     SourceGenerator generator { builder };
 
@@ -3357,15 +3361,27 @@ static void generate_prototype_or_global_mixin_definitions(IDL::Interface const&
         generator.set("iterator_name", ByteString::formatted("{}Iterator", interface.name));
     }
 
-    if (is_global_interface) {
-        generator.set("named_properties_class", ByteString::formatted("{}Properties", interface.name));
-        // Doing this with macros is not super nice, but simplifies codegen a lot.
-        generator.append(R"~~~(
-#define define_direct_property (object.define_direct_property)
-#define define_native_accessor (object.define_native_accessor)
-#define define_native_function (object.define_native_function)
-#define set_prototype (object.set_prototype)
+    bool define_on_existing_object = is_global_interface || generate_unforgeables == GenerateUnforgeables::Yes;
 
+    if (define_on_existing_object) {
+        generator.set("define_direct_property", "object.define_direct_property");
+        generator.set("define_native_accessor", "object.define_native_accessor");
+        generator.set("define_native_function", "object.define_native_function");
+        generator.set("set_prototype", "object.set_prototype");
+    } else {
+        generator.set("define_direct_property", "define_direct_property");
+        generator.set("define_native_accessor", "define_native_accessor");
+        generator.set("define_native_function", "define_native_function");
+        generator.set("set_prototype", "set_prototype");
+    }
+
+    if (generate_unforgeables == GenerateUnforgeables::Yes) {
+        generator.append(R"~~~(
+void @class_name@::define_unforgeable_attributes(JS::Realm& realm, [[maybe_unused]] JS::Object& object)
+{
+)~~~");
+    } else if (is_global_interface) {
+        generator.append(R"~~~(
 void @class_name@::initialize(JS::Realm& realm, JS::Object& object)
 {
 )~~~");
@@ -3376,38 +3392,49 @@ void @class_name@::initialize(JS::Realm& realm)
 )~~~");
     }
 
-    // FIXME: Currently almost everything gets default_attributes but it should be configurable per attribute.
-    //        See the spec links for details
     generator.append(R"~~~(
 
     [[maybe_unused]] auto& vm = realm.vm();
+
+)~~~");
+
+    // FIXME: Currently almost everything gets default_attributes but it should be configurable per attribute.
+    //        See the spec links for details
+    if (generate_unforgeables == GenerateUnforgeables::No) {
+        generator.append(R"~~~(
     [[maybe_unused]] u8 default_attributes = JS::Attribute::Enumerable | JS::Attribute::Configurable | JS::Attribute::Writable;
-
-)~~~");
-
-    if (interface.name == "DOMException"sv) {
-        generator.append(R"~~~(
-
-    set_prototype(realm.intrinsics().error_prototype());
-)~~~");
-    }
-
-    else if (interface.prototype_base_class == "ObjectPrototype") {
-        generator.append(R"~~~(
-
-    set_prototype(realm.intrinsics().object_prototype());
-
-)~~~");
-    } else if (is_global_interface) {
-        generator.append(R"~~~(
-    set_prototype(&ensure_web_prototype<@prototype_name@>(realm, "@name@"_fly_string));
 )~~~");
     } else {
         generator.append(R"~~~(
+    [[maybe_unused]] u8 default_attributes = JS::Attribute::Enumerable;
+)~~~");
+    }
 
-    set_prototype(&ensure_web_prototype<@prototype_base_class@>(realm, "@parent_name@"_fly_string));
+    if (generate_unforgeables == GenerateUnforgeables::No) {
+        if (interface.name == "DOMException"sv) {
+            generator.append(R"~~~(
+
+    @set_prototype@(realm.intrinsics().error_prototype());
+)~~~");
+        }
+
+        else if (interface.prototype_base_class == "ObjectPrototype") {
+            generator.append(R"~~~(
+
+    @set_prototype@(realm.intrinsics().object_prototype());
 
 )~~~");
+        } else if (is_global_interface) {
+            generator.append(R"~~~(
+    @set_prototype@(&ensure_web_prototype<@prototype_name@>(realm, "@name@"_fly_string));
+)~~~");
+        } else {
+            generator.append(R"~~~(
+
+    @set_prototype@(&ensure_web_prototype<@prototype_base_class@>(realm, "@parent_name@"_fly_string));
+
+)~~~");
+        }
     }
 
     if (interface.has_unscopable_member) {
@@ -3418,11 +3445,15 @@ void @class_name@::initialize(JS::Realm& realm)
 
     // https://webidl.spec.whatwg.org/#es-attributes
     for (auto& attribute : interface.attributes) {
+        bool has_unforgeable_attribute = attribute.extended_attributes.contains("LegacyUnforgeable"sv);
+        if ((generate_unforgeables == GenerateUnforgeables::Yes && !has_unforgeable_attribute) || (generate_unforgeables == GenerateUnforgeables::No && has_unforgeable_attribute))
+            continue;
+
         if (attribute.extended_attributes.contains("FIXME")) {
             auto fixme_attribute_generator = generator.fork();
             fixme_attribute_generator.set("attribute.name", attribute.name);
             fixme_attribute_generator.append(R"~~~(
-    define_direct_property("@attribute.name@"_fly_string, JS::js_undefined(), default_attributes | JS::Attribute::Unimplemented);
+    @define_direct_property@("@attribute.name@"_fly_string, JS::js_undefined(), default_attributes | JS::Attribute::Unimplemented);
             )~~~");
             continue;
         }
@@ -3443,36 +3474,47 @@ void @class_name@::initialize(JS::Realm& realm)
         }
 
         attribute_generator.append(R"~~~(
-    define_native_accessor(realm, "@attribute.name@"_fly_string, @attribute.getter_callback@, @attribute.setter_callback@, default_attributes);
+    @define_native_accessor@(realm, "@attribute.name@"_fly_string, @attribute.getter_callback@, @attribute.setter_callback@, default_attributes);
 )~~~");
     }
 
     for (auto& function : interface.functions) {
+        bool has_unforgeable_attribute = function.extended_attributes.contains("LegacyUnforgeable"sv);
+        if ((generate_unforgeables == GenerateUnforgeables::Yes && !has_unforgeable_attribute) || (generate_unforgeables == GenerateUnforgeables::No && has_unforgeable_attribute))
+            continue;
+
         if (function.extended_attributes.contains("FIXME")) {
             auto fixme_function_generator = generator.fork();
             fixme_function_generator.set("function.name", function.name);
             fixme_function_generator.append(R"~~~(
-        define_direct_property("@function.name@"_fly_string, JS::js_undefined(), default_attributes | JS::Attribute::Unimplemented);
+        @define_direct_property@("@function.name@"_fly_string, JS::js_undefined(), default_attributes | JS::Attribute::Unimplemented);
             )~~~");
         }
     }
 
     // https://webidl.spec.whatwg.org/#es-constants
-    for (auto& constant : interface.constants) {
-        // FIXME: Do constants need to be added to the unscopable list?
+    if (generate_unforgeables == GenerateUnforgeables::No) {
+        for (auto& constant : interface.constants) {
+            // FIXME: Do constants need to be added to the unscopable list?
 
-        auto constant_generator = generator.fork();
-        constant_generator.set("constant.name", constant.name);
+            auto constant_generator = generator.fork();
+            constant_generator.set("constant.name", constant.name);
 
-        generate_wrap_statement(constant_generator, constant.value, constant.type, interface, ByteString::formatted("auto constant_{}_value =", constant.name));
+            generate_wrap_statement(constant_generator, constant.value, constant.type, interface, ByteString::formatted("auto constant_{}_value =", constant.name));
 
-        constant_generator.append(R"~~~(
-    define_direct_property("@constant.name@"_fly_string, constant_@constant.name@_value, JS::Attribute::Enumerable);
+            constant_generator.append(R"~~~(
+    @define_direct_property@("@constant.name@"_fly_string, constant_@constant.name@_value, JS::Attribute::Enumerable);
 )~~~");
+        }
     }
 
     // https://webidl.spec.whatwg.org/#es-operations
     for (auto const& overload_set : interface.overload_sets) {
+        // NOTE: This assumes that every function in the overload set has the same attribute set.
+        bool has_unforgeable_attribute = any_of(overload_set.value, [](auto const& function) { return function.extended_attributes.contains("LegacyUnforgeable"); });
+        if ((generate_unforgeables == GenerateUnforgeables::Yes && !has_unforgeable_attribute) || (generate_unforgeables == GenerateUnforgeables::No && has_unforgeable_attribute))
+            continue;
+
         auto function_generator = generator.fork();
         function_generator.set("function.name", overload_set.key);
         function_generator.set("function.name:snakecase", make_input_acceptable_cpp(overload_set.key.to_snakecase()));
@@ -3486,95 +3528,103 @@ void @class_name@::initialize(JS::Realm& realm)
         }
 
         function_generator.append(R"~~~(
-    define_native_function(realm, "@function.name@"_fly_string, @function.name:snakecase@, @function.length@, default_attributes);
+    @define_native_function@(realm, "@function.name@"_fly_string, @function.name:snakecase@, @function.length@, default_attributes);
 )~~~");
     }
 
-    if (interface.has_stringifier) {
-        // FIXME: Do stringifiers need to be added to the unscopable list?
+    bool should_generate_stringifier = true;
+    if (interface.stringifier_attribute.has_value()) {
+        bool has_unforgeable_attribute = interface.stringifier_attribute.value().extended_attributes.contains("LegacyUnforgeable"sv);
+        if ((generate_unforgeables == GenerateUnforgeables::Yes && !has_unforgeable_attribute) || (generate_unforgeables == GenerateUnforgeables::No && has_unforgeable_attribute))
+            should_generate_stringifier = false;
+    }
 
+    if (interface.has_stringifier && should_generate_stringifier) {
+        // FIXME: Do stringifiers need to be added to the unscopable list?
         auto stringifier_generator = generator.fork();
         stringifier_generator.append(R"~~~(
-    define_native_function(realm, "toString"_fly_string, to_string, 0, default_attributes);
+    @define_native_function@(realm, "toString"_fly_string, to_string, 0, default_attributes);
 )~~~");
     }
 
     // https://webidl.spec.whatwg.org/#define-the-iteration-methods
     // This applies to this if block and the following if block.
-    if (interface.indexed_property_getter.has_value()) {
+    if (interface.indexed_property_getter.has_value() && generate_unforgeables == GenerateUnforgeables::No) {
         auto iterator_generator = generator.fork();
         iterator_generator.append(R"~~~(
-    define_direct_property(vm.well_known_symbol_iterator(), realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.values), JS::Attribute::Configurable | JS::Attribute::Writable);
+    @define_direct_property@(vm.well_known_symbol_iterator(), realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.values), JS::Attribute::Configurable | JS::Attribute::Writable);
 )~~~");
 
         if (interface.value_iterator_type.has_value()) {
             iterator_generator.append(R"~~~(
-    define_direct_property(vm.names.entries, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.entries), default_attributes);
-    define_direct_property(vm.names.keys, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.keys), default_attributes);
-    define_direct_property(vm.names.values, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.values), default_attributes);
-    define_direct_property(vm.names.forEach, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.forEach), default_attributes);
+    @define_direct_property@(vm.names.entries, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.entries), default_attributes);
+    @define_direct_property@(vm.names.keys, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.keys), default_attributes);
+    @define_direct_property@(vm.names.values, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.values), default_attributes);
+    @define_direct_property@(vm.names.forEach, realm.intrinsics().array_prototype()->get_without_side_effects(vm.names.forEach), default_attributes);
 )~~~");
         }
     }
 
-    if (interface.pair_iterator_types.has_value()) {
+    if (interface.pair_iterator_types.has_value() && generate_unforgeables == GenerateUnforgeables::No) {
         // FIXME: Do pair iterators need to be added to the unscopable list?
 
         auto iterator_generator = generator.fork();
         iterator_generator.append(R"~~~(
-    define_native_function(realm, vm.names.entries, entries, 0, default_attributes);
-    define_native_function(realm, vm.names.forEach, for_each, 1, default_attributes);
-    define_native_function(realm, vm.names.keys, keys, 0, default_attributes);
-    define_native_function(realm, vm.names.values, values, 0, default_attributes);
+    @define_native_function@(realm, vm.names.entries, entries, 0, default_attributes);
+    @define_native_function@(realm, vm.names.forEach, for_each, 1, default_attributes);
+    @define_native_function@(realm, vm.names.keys, keys, 0, default_attributes);
+    @define_native_function@(realm, vm.names.values, values, 0, default_attributes);
 
-    define_direct_property(vm.well_known_symbol_iterator(), get_without_side_effects(vm.names.entries), JS::Attribute::Configurable | JS::Attribute::Writable);
+    @define_direct_property@(vm.well_known_symbol_iterator(), get_without_side_effects(vm.names.entries), JS::Attribute::Configurable | JS::Attribute::Writable);
 )~~~");
     }
 
     // https://webidl.spec.whatwg.org/#js-setlike
-    if (interface.set_entry_type.has_value()) {
+    if (interface.set_entry_type.has_value() && generate_unforgeables == GenerateUnforgeables::No) {
 
         auto setlike_generator = generator.fork();
 
         setlike_generator.append(R"~~~(
-    define_native_accessor(realm, vm.names.size, get_size, nullptr, JS::Attribute::Enumerable | JS::Attribute::Configurable);
-    define_native_function(realm, vm.names.entries, entries, 0, default_attributes);
+    @define_native_accessor@(realm, vm.names.size, get_size, nullptr, JS::Attribute::Enumerable | JS::Attribute::Configurable);
+    @define_native_function@(realm, vm.names.entries, entries, 0, default_attributes);
     // NOTE: Keys intentionally returns values for setlike
-    define_native_function(realm, vm.names.keys, values, 0, default_attributes);
-    define_native_function(realm, vm.names.values, values, 0, default_attributes);
-    define_direct_property(vm.well_known_symbol_iterator(), get_without_side_effects(vm.names.values), JS::Attribute::Configurable | JS::Attribute::Writable);
-    define_native_function(realm, vm.names.forEach, for_each, 1, default_attributes);
-    define_native_function(realm, vm.names.has, has, 1, default_attributes);
+    @define_native_function@(realm, vm.names.keys, values, 0, default_attributes);
+    @define_native_function@(realm, vm.names.values, values, 0, default_attributes);
+    @define_direct_property@(vm.well_known_symbol_iterator(), get_without_side_effects(vm.names.values), JS::Attribute::Configurable | JS::Attribute::Writable);
+    @define_native_function@(realm, vm.names.forEach, for_each, 1, default_attributes);
+    @define_native_function@(realm, vm.names.has, has, 1, default_attributes);
 )~~~");
 
         if (!interface.overload_sets.contains("add"sv) && !interface.is_set_readonly) {
             setlike_generator.append(R"~~~(
-    define_native_function(realm, vm.names.add, add, 1, default_attributes);
+    @define_native_function@(realm, vm.names.add, add, 1, default_attributes);
 )~~~");
         }
         if (!interface.overload_sets.contains("delete"sv) && !interface.is_set_readonly) {
             setlike_generator.append(R"~~~(
-    define_native_function(realm, vm.names.delete_, delete_, 1, default_attributes);
+    @define_native_function@(realm, vm.names.delete_, delete_, 1, default_attributes);
 )~~~");
         }
         if (!interface.overload_sets.contains("clear"sv) && !interface.is_set_readonly) {
             setlike_generator.append(R"~~~(
-    define_native_function(realm, vm.names.clear, clear, 0, default_attributes);
+    @define_native_function@(realm, vm.names.clear, clear, 0, default_attributes);
 )~~~");
         }
     }
 
     if (interface.has_unscopable_member) {
         generator.append(R"~~~(
-    define_direct_property(vm.well_known_symbol_unscopables(), unscopable_object, JS::Attribute::Configurable);
+    @define_direct_property@(vm.well_known_symbol_unscopables(), unscopable_object, JS::Attribute::Configurable);
 )~~~");
     }
 
-    generator.append(R"~~~(
-    define_direct_property(vm.well_known_symbol_to_string_tag(), JS::PrimitiveString::create(vm, "@namespaced_name@"_string), JS::Attribute::Configurable);
+    if (generate_unforgeables == GenerateUnforgeables::No) {
+        generator.append(R"~~~(
+    @define_direct_property@(vm.well_known_symbol_to_string_tag(), JS::PrimitiveString::create(vm, "@namespaced_name@"_string), JS::Attribute::Configurable);
 )~~~");
+    }
 
-    if (!is_global_interface) {
+    if (!define_on_existing_object) {
         generator.append(R"~~~(
     Base::initialize(realm);
 )~~~");
@@ -3583,6 +3633,26 @@ void @class_name@::initialize(JS::Realm& realm)
     generator.append(R"~~~(
 }
 )~~~");
+}
+
+// https://webidl.spec.whatwg.org/#interface-prototype-object
+static void generate_prototype_or_global_mixin_definitions(IDL::Interface const& interface, StringBuilder& builder)
+{
+    SourceGenerator generator { builder };
+
+    auto is_global_interface = interface.extended_attributes.contains("Global");
+    auto class_name = is_global_interface ? interface.global_mixin_class : interface.prototype_class;
+    generator.set("name", interface.name);
+    generator.set("namespaced_name", interface.namespaced_name);
+    generator.set("class_name", class_name);
+    generator.set("fully_qualified_name", interface.fully_qualified_name);
+    generator.set("parent_name", interface.parent_name);
+    generator.set("prototype_base_class", interface.prototype_base_class);
+    generator.set("prototype_name", interface.prototype_class); // Used for Global Mixin
+
+    if (interface.pair_iterator_types.has_value()) {
+        generator.set("iterator_name", ByteString::formatted("{}Iterator", interface.name));
+    }
 
     if (!interface.attributes.is_empty() || !interface.functions.is_empty() || interface.has_stringifier) {
         generator.append(R"~~~(
@@ -4214,7 +4284,7 @@ JS_DEFINE_NATIVE_FUNCTION(@class_name@::@attribute.setter_callback@)
         auto stringifier_generator = generator.fork();
         stringifier_generator.set("class_name", class_name);
         if (interface.stringifier_attribute.has_value())
-            stringifier_generator.set("attribute.cpp_getter_name", interface.stringifier_attribute->to_snakecase());
+            stringifier_generator.set("attribute.cpp_getter_name", interface.stringifier_attribute.value().name.to_snakecase());
 
         stringifier_generator.append(R"~~~(
 JS_DEFINE_NATIVE_FUNCTION(@class_name@::to_string)
@@ -4955,6 +5025,8 @@ class @prototype_class@ : public JS::Object {
     JS_OBJECT(@prototype_class@, JS::Object);
     GC_DECLARE_ALLOCATOR(@prototype_class@);
 public:
+    static void define_unforgeable_attributes(JS::Realm&, JS::Object&);
+
     explicit @prototype_class@(JS::Realm&);
     virtual void initialize(JS::Realm&) override;
     virtual ~@prototype_class@() override;
@@ -5124,6 +5196,8 @@ void @prototype_class@::initialize(JS::Realm& realm)
         if (interface.supports_named_properties())
             generate_named_properties_object_definitions(interface, builder);
     } else {
+        generate_prototype_or_global_mixin_initialization(interface, builder, GenerateUnforgeables::No);
+        generate_prototype_or_global_mixin_initialization(interface, builder, GenerateUnforgeables::Yes);
         generate_prototype_or_global_mixin_definitions(interface, builder);
     }
 
@@ -5250,6 +5324,7 @@ namespace Web::Bindings {
 class @class_name@ {
 public:
     void initialize(JS::Realm&, JS::Object&);
+    void define_unforgeable_attributes(JS::Realm&, JS::Object&);
     @class_name@();
     virtual ~@class_name@();
 
@@ -5313,6 +5388,8 @@ namespace Web::Bindings {
 @class_name@::~@class_name@() = default;
 )~~~");
 
+    generate_prototype_or_global_mixin_initialization(interface, builder, GenerateUnforgeables::No);
+    generate_prototype_or_global_mixin_initialization(interface, builder, GenerateUnforgeables::Yes);
     generate_prototype_or_global_mixin_definitions(interface, builder);
 
     generator.append(R"~~~(

Tests/LibWeb/Text/expected/DOM/Document-has-unforgeable-properties.txt

@@ -0,0 +1,36 @@
+location exists on document itself: true
+location does not exist on LocationPrototype: true
+location descriptor is not undefined: true
+location enumerable: true
+location configurable: false
+location writable: undefined
+location exists on document itself: true
+location does not exist on LocationPrototype: true
+location descriptor is not undefined: true
+location enumerable: true
+location configurable: false
+location writable: undefined
+location exists on document itself: true
+location does not exist on LocationPrototype: true
+location descriptor is not undefined: true
+location enumerable: true
+location configurable: false
+location writable: undefined
+location exists on document itself: true
+location does not exist on LocationPrototype: true
+location descriptor is not undefined: true
+location enumerable: true
+location configurable: false
+location writable: undefined
+location exists on document itself: true
+location does not exist on LocationPrototype: true
+location descriptor is not undefined: true
+location enumerable: true
+location configurable: false
+location writable: undefined
+location exists on document itself: true
+location does not exist on LocationPrototype: true
+location descriptor is not undefined: true
+location enumerable: true
+location configurable: false
+location writable: undefined

Tests/LibWeb/Text/expected/DOM/Event-has-unforgeable-properties.txt

@@ -0,0 +1,18 @@
+isTrusted exists on Event instance itself: true
+isTrusted does not exist on LocationPrototype: true
+isTrusted descriptor is not undefined: true
+isTrusted enumerable: true
+isTrusted configurable: false
+isTrusted writable: undefined
+isTrusted exists on UIEvent instance itself: true
+isTrusted does not exist on LocationPrototype: true
+isTrusted descriptor is not undefined: true
+isTrusted enumerable: true
+isTrusted configurable: false
+isTrusted writable: undefined
+isTrusted exists on CustomEvent instance itself: true
+isTrusted does not exist on LocationPrototype: true
+isTrusted descriptor is not undefined: true
+isTrusted enumerable: true
+isTrusted configurable: false
+isTrusted writable: undefined

Tests/LibWeb/Text/expected/HTML/Location-has-unforgeable-properties.txt

@@ -0,0 +1,156 @@
+href exists on location itself: true
+href does not exist on LocationPrototype: true
+href descriptor is not undefined: true
+href enumerable: true
+href configurable: true
+href writable: undefined
+origin exists on location itself: true
+origin does not exist on LocationPrototype: true
+origin descriptor is not undefined: true
+origin enumerable: true
+origin configurable: true
+origin writable: undefined
+protocol exists on location itself: true
+protocol does not exist on LocationPrototype: true
+protocol descriptor is not undefined: true
+protocol enumerable: true
+protocol configurable: true
+protocol writable: undefined
+host exists on location itself: true
+host does not exist on LocationPrototype: true
+host descriptor is not undefined: true
+host enumerable: true
+host configurable: true
+host writable: undefined
+hostname exists on location itself: true
+hostname does not exist on LocationPrototype: true
+hostname descriptor is not undefined: true
+hostname enumerable: true
+hostname configurable: true
+hostname writable: undefined
+port exists on location itself: true
+port does not exist on LocationPrototype: true
+port descriptor is not undefined: true
+port enumerable: true
+port configurable: true
+port writable: undefined
+pathname exists on location itself: true
+pathname does not exist on LocationPrototype: true
+pathname descriptor is not undefined: true
+pathname enumerable: true
+pathname configurable: true
+pathname writable: undefined
+search exists on location itself: true
+search does not exist on LocationPrototype: true
+search descriptor is not undefined: true
+search enumerable: true
+search configurable: true
+search writable: undefined
+hash exists on location itself: true
+hash does not exist on LocationPrototype: true
+hash descriptor is not undefined: true
+hash enumerable: true
+hash configurable: true
+hash writable: undefined
+assign exists on location itself: true
+assign does not exist on LocationPrototype: true
+assign descriptor is not undefined: true
+assign enumerable: true
+assign configurable: true
+assign writable: false
+replace exists on location itself: true
+replace does not exist on LocationPrototype: true
+replace descriptor is not undefined: true
+replace enumerable: true
+replace configurable: true
+replace writable: false
+reload exists on location itself: true
+reload does not exist on LocationPrototype: true
+reload descriptor is not undefined: true
+reload enumerable: true
+reload configurable: true
+reload writable: false
+toString exists on location itself: true
+toString does not exist on LocationPrototype: true
+toString descriptor is not undefined: true
+toString enumerable: true
+toString configurable: true
+toString writable: false
+href exists on document.location itself: true
+href does not exist on LocationPrototype: true
+href descriptor is not undefined: true
+href enumerable: true
+href configurable: true
+href writable: undefined
+origin exists on document.location itself: true
+origin does not exist on LocationPrototype: true
+origin descriptor is not undefined: true
+origin enumerable: true
+origin configurable: true
+origin writable: undefined
+protocol exists on document.location itself: true
+protocol does not exist on LocationPrototype: true
+protocol descriptor is not undefined: true
+protocol enumerable: true
+protocol configurable: true
+protocol writable: undefined
+host exists on document.location itself: true
+host does not exist on LocationPrototype: true
+host descriptor is not undefined: true
+host enumerable: true
+host configurable: true
+host writable: undefined
+hostname exists on document.location itself: true
+hostname does not exist on LocationPrototype: true
+hostname descriptor is not undefined: true
+hostname enumerable: true
+hostname configurable: true
+hostname writable: undefined
+port exists on document.location itself: true
+port does not exist on LocationPrototype: true
+port descriptor is not undefined: true
+port enumerable: true
+port configurable: true
+port writable: undefined
+pathname exists on document.location itself: true
+pathname does not exist on LocationPrototype: true
+pathname descriptor is not undefined: true
+pathname enumerable: true
+pathname configurable: true
+pathname writable: undefined
+search exists on document.location itself: true
+search does not exist on LocationPrototype: true
+search descriptor is not undefined: true
+search enumerable: true
+search configurable: true
+search writable: undefined
+hash exists on document.location itself: true
+hash does not exist on LocationPrototype: true
+hash descriptor is not undefined: true
+hash enumerable: true
+hash configurable: true
+hash writable: undefined
+assign exists on document.location itself: true
+assign does not exist on LocationPrototype: true
+assign descriptor is not undefined: true
+assign enumerable: true
+assign configurable: true
+assign writable: false
+replace exists on document.location itself: true
+replace does not exist on LocationPrototype: true
+replace descriptor is not undefined: true
+replace enumerable: true
+replace configurable: true
+replace writable: false
+reload exists on document.location itself: true
+reload does not exist on LocationPrototype: true
+reload descriptor is not undefined: true
+reload enumerable: true
+reload configurable: true
+reload writable: false
+toString exists on document.location itself: true
+toString does not exist on LocationPrototype: true
+toString descriptor is not undefined: true
+toString enumerable: true
+toString configurable: true
+toString writable: false

Tests/LibWeb/Text/expected/HTML/Window-has-unforgeable-properties.txt

@@ -0,0 +1,24 @@
+window exists on window itself: true
+window does not exist on LocationPrototype: true
+window descriptor is not undefined: true
+window enumerable: true
+window configurable: false
+window writable: undefined
+document exists on window itself: true
+document does not exist on LocationPrototype: true
+document descriptor is not undefined: true
+document enumerable: true
+document configurable: false
+document writable: undefined
+location exists on window itself: true
+location does not exist on LocationPrototype: true
+location descriptor is not undefined: true
+location enumerable: true
+location configurable: false
+location writable: undefined
+top exists on window itself: true
+top does not exist on LocationPrototype: true
+top descriptor is not undefined: true
+top enumerable: true
+top configurable: false
+top writable: undefined

Tests/LibWeb/Text/input/DOM/Document-has-unforgeable-properties.html

@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const unforgeableProperties = [
+            "location",
+        ];
+
+        const documents = [
+            document,
+            new Document(),
+            document.implementation.createDocument("http://www.w3.org/1999/xhtml", null, null),
+            document.implementation.createDocument("http://www.w3.org/2000/svg", null, null),
+            document.implementation.createDocument(null, null, null),
+            document.implementation.createHTMLDocument(),
+        ];
+
+        for (const document of documents) {
+            const documentPrototype = Object.getPrototypeOf(document);
+
+            for (const property of unforgeableProperties) { 
+                println(`${property} exists on document itself: ${Object.hasOwn(document, property)}`);
+                println(`${property} does not exist on LocationPrototype: ${!Object.hasOwn(documentPrototype, property)}`);
+                
+                const propertyDescriptor = Object.getOwnPropertyDescriptor(document, property);
+                println(`${property} descriptor is not undefined: ${propertyDescriptor !== undefined}`);
+                println(`${property} enumerable: ${propertyDescriptor.enumerable}`);
+                println(`${property} configurable: ${propertyDescriptor.configurable}`);
+                println(`${property} writable: ${propertyDescriptor.writable}`);
+            }
+        }
+    });
+</script>

Tests/LibWeb/Text/input/DOM/Event-has-unforgeable-properties.html

@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const unforgeableProperties = [
+            "isTrusted",
+        ];
+
+        for (const eventType of [Event, UIEvent, CustomEvent]) {
+            const event = new eventType("test");
+            const eventPrototype = Object.getPrototypeOf(event);
+
+            for (const property of unforgeableProperties) { 
+                println(`${property} exists on ${eventType.name} instance itself: ${Object.hasOwn(event, property)}`);
+                println(`${property} does not exist on LocationPrototype: ${!Object.hasOwn(eventPrototype, property)}`);
+                
+                const propertyDescriptor = Object.getOwnPropertyDescriptor(event, property);
+                println(`${property} descriptor is not undefined: ${propertyDescriptor !== undefined}`);
+                println(`${property} enumerable: ${propertyDescriptor.enumerable}`);
+                println(`${property} configurable: ${propertyDescriptor.configurable}`);
+                println(`${property} writable: ${propertyDescriptor.writable}`);
+            }
+        }
+    });
+</script>

Tests/LibWeb/Text/input/HTML/Location-has-unforgeable-properties.html

@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        for (const { location, name } of [{ location: window.location, name: "location" }, { location: document.location, name: "document.location" }]) {
+            const unforgeableProperties = [
+                "href",
+                "origin",
+                "protocol",
+                "host",
+                "hostname",
+                "port",
+                "pathname",
+                "search",
+                "hash",
+                "assign",
+                "replace",
+                "reload",
+                // FIXME: "ancestorOrigins",
+                "toString",
+            ];
+
+            const locationPrototype = Object.getPrototypeOf(location);
+
+            for (const property of unforgeableProperties) {
+                println(`${property} exists on ${name} itself: ${Object.hasOwn(location, property)}`);
+                println(`${property} does not exist on LocationPrototype: ${!Object.hasOwn(locationPrototype, property)}`);
+                
+                const propertyDescriptor = Object.getOwnPropertyDescriptor(location, property);
+                println(`${property} descriptor is not undefined: ${propertyDescriptor !== undefined}`);
+                println(`${property} enumerable: ${propertyDescriptor.enumerable}`);
+                println(`${property} configurable: ${propertyDescriptor.configurable}`);
+                println(`${property} writable: ${propertyDescriptor.writable}`);
+            }
+        }
+    });
+</script>

Tests/LibWeb/Text/input/HTML/Window-has-unforgeable-properties.html

@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const unforgeableProperties = [
+            "window",
+            "document",
+            "location",
+            "top",
+        ];
+
+        const windowPrototype = Object.getPrototypeOf(window);
+
+        for (const property of unforgeableProperties) { 
+            println(`${property} exists on window itself: ${Object.hasOwn(window, property)}`);
+            println(`${property} does not exist on LocationPrototype: ${!Object.hasOwn(windowPrototype, property)}`);
+            
+            const propertyDescriptor = Object.getOwnPropertyDescriptor(window, property);
+            println(`${property} descriptor is not undefined: ${propertyDescriptor !== undefined}`);
+            println(`${property} enumerable: ${propertyDescriptor.enumerable}`);
+            println(`${property} configurable: ${propertyDescriptor.configurable}`);
+            println(`${property} writable: ${propertyDescriptor.writable}`);
+        }
+    });
+</script>