LibWeb/CSS: Stub out CSSStyleValue

Libraries/LibWeb/CMakeLists.txt

@@ -128,6 +128,7 @@ set(SOURCES
     CSS/CSSStyleProperties.cpp
     CSS/CSSStyleRule.cpp
     CSS/CSSStyleSheet.cpp
+    CSS/CSSStyleValue.cpp
     CSS/CSSSupportsRule.cpp
     CSS/CSSTransition.cpp
     CSS/Descriptor.cpp

Libraries/LibWeb/CSS/CSSStyleValue.cpp

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "CSSStyleValue.h"
+#include <LibWeb/Bindings/CSSStyleValuePrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::CSS {
+
+GC_DEFINE_ALLOCATOR(CSSStyleValue);
+
+GC::Ref<CSSStyleValue> CSSStyleValue::create(JS::Realm& realm, Optional<String> associated_property, Optional<String> constructed_from_string)
+{
+    return realm.create<CSSStyleValue>(realm, move(associated_property), move(constructed_from_string));
+}
+
+CSSStyleValue::CSSStyleValue(JS::Realm& realm, Optional<String> associated_property, Optional<String> constructed_from_string)
+    : PlatformObject(realm)
+    , m_associated_property(move(associated_property))
+    , m_constructed_from_string(move(constructed_from_string))
+{
+}
+
+void CSSStyleValue::initialize(JS::Realm& realm)
+{
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(CSSStyleValue);
+    Base::initialize(realm);
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#stylevalue-serialization
+String CSSStyleValue::to_string() const
+{
+    // if the value was constructed from a USVString
+    if (m_constructed_from_string.has_value()) {
+        // the serialization is the USVString from which the value was constructed.
+        return m_constructed_from_string.value();
+    }
+    // FIXME: otherwise, if the value was constructed using an IDL constructor
+    {
+        // the serialization is specified in the sections below.
+    }
+    // FIXME: otherwise, if the value was extracted from the CSSOM
+    {
+        // the serialization is specified in §6.7 Serialization from CSSOM Values below.
+    }
+    return {};
+}
+
+}

Libraries/LibWeb/CSS/CSSStyleValue.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/Bindings/PlatformObject.h>
+
+namespace Web::CSS {
+
+// https://drafts.css-houdini.org/css-typed-om-1/#cssstylevalue
+class CSSStyleValue : public Bindings::PlatformObject {
+    WEB_PLATFORM_OBJECT(CSSStyleValue, Bindings::PlatformObject);
+    GC_DECLARE_ALLOCATOR(CSSStyleValue);
+
+public:
+    [[nodiscard]] static GC::Ref<CSSStyleValue> create(JS::Realm&, Optional<String> associated_property = {}, Optional<String> constructed_from_string = {});
+
+    virtual ~CSSStyleValue() override = default;
+
+    virtual String to_string() const;
+
+private:
+    explicit CSSStyleValue(JS::Realm&, Optional<String> associated_property = {}, Optional<String> constructed_from_string = {});
+
+    virtual void initialize(JS::Realm&) override;
+
+    // https://drafts.css-houdini.org/css-typed-om-1/#dom-cssstylevalue-associatedproperty-slot
+    Optional<String> m_associated_property;
+
+    Optional<String> m_constructed_from_string;
+};
+
+}

Libraries/LibWeb/CSS/CSSStyleValue.idl

@@ -0,0 +1,8 @@
+// https://drafts.css-houdini.org/css-typed-om-1/#cssstylevalue
+// FIXME: [Exposed=(Window, Worker, PaintWorklet, LayoutWorklet)]
+[Exposed=(Window, Worker)]
+interface CSSStyleValue {
+    stringifier;
+    [FIXME, Exposed=Window] static CSSStyleValue parse(USVString property, USVString cssText);
+    [FIXME, Exposed=Window] static sequence<CSSStyleValue> parseAll(USVString property, USVString cssText);
+};

Libraries/LibWeb/Forward.h

@@ -252,6 +252,7 @@ class CSSStyleDeclaration;
 class CSSStyleProperties;
 class CSSStyleRule;
 class CSSStyleSheet;
+class CSSStyleValue;
 class CSSSupportsRule;
 class CursorStyleValue;
 class CustomIdentStyleValue;

Libraries/LibWeb/idl_files.cmake

@@ -48,6 +48,7 @@ libweb_js_bindings(CSS/CSSStyleDeclaration)
 libweb_js_bindings(CSS/CSSStyleProperties)
 libweb_js_bindings(CSS/CSSStyleRule)
 libweb_js_bindings(CSS/CSSStyleSheet)
+libweb_js_bindings(CSS/CSSStyleValue)
 libweb_js_bindings(CSS/CSSSupportsRule)
 libweb_js_bindings(CSS/CSSTransition)
 libweb_js_bindings(CSS/FontFace)

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

@@ -54,6 +54,7 @@ static bool is_platform_object(Type const& type)
         "Credential"sv,
         "CredentialsContainer"sv,
         "CryptoKey"sv,
+        "CSSStyleValue"sv,
         "CustomStateSet"sv,
         "DataTransfer"sv,
         "Document"sv,

Tests/LibWeb/Text/expected/all-window-properties.txt

@@ -60,6 +60,7 @@ CSSStyleDeclaration
 CSSStyleProperties
 CSSStyleRule
 CSSStyleSheet
+CSSStyleValue
 CSSSupportsRule
 CSSTransition
 CacheStorage

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-objects/parse-invalid.txt

@@ -2,9 +2,9 @@ Harness status: OK
 
 Found 5 tests
 
-5 Fail
-Fail	CSSStyleValue.parse() with empty property name throws TypeError
-Fail	CSSStyleValue.parse() with unsupported property name throws TypeError
-Fail	CSSStyleValue.parse() with invalid value for valid property throws TypeError
-Fail	CSSStyleValue.parse() with invalid value for shorthand property throws TypeError
-Fail	CSSStyleValue.parse() with invalid value for custom property throws TypeError
+5 Pass
+Pass	CSSStyleValue.parse() with empty property name throws TypeError
+Pass	CSSStyleValue.parse() with unsupported property name throws TypeError
+Pass	CSSStyleValue.parse() with invalid value for valid property throws TypeError
+Pass	CSSStyleValue.parse() with invalid value for shorthand property throws TypeError
+Pass	CSSStyleValue.parse() with invalid value for custom property throws TypeError

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-objects/parseAll-invalid.txt

@@ -2,10 +2,10 @@ Harness status: OK
 
 Found 6 tests
 
-6 Fail
-Fail	CSSStyleValue.parseAll() with empty property name throws TypeError
-Fail	CSSStyleValue.parseAll() with unsupported property name throws TypeError
-Fail	CSSStyleValue.parseAll() with invalid value for valid property throws TypeError
-Fail	CSSStyleValue.parseAll() with invalid value for shorthand property throws TypeError
-Fail	CSSStyleValue.parseAll() with invalid value for custom property throws TypeError
-Fail	CSSStyleValue.parseAll() with invalid value for property throws TypeError
+6 Pass
+Pass	CSSStyleValue.parseAll() with empty property name throws TypeError
+Pass	CSSStyleValue.parseAll() with unsupported property name throws TypeError
+Pass	CSSStyleValue.parseAll() with invalid value for valid property throws TypeError
+Pass	CSSStyleValue.parseAll() with invalid value for shorthand property throws TypeError
+Pass	CSSStyleValue.parseAll() with invalid value for custom property throws TypeError
+Pass	CSSStyleValue.parseAll() with invalid value for property throws TypeError