LibWeb/CSS: Implement CSSUnparsedValue and CSSVariableReferenceValue

We don't serialize these the way WPT expects, because we don't implement
the comment-insertion rules from CSS-Syntax. We don't implement that
for regular serialization either, so it's something we can worry about
later.

Libraries/LibWeb/CMakeLists.txt

@@ -132,6 +132,8 @@ set(SOURCES
     CSS/CSSStyleValue.cpp
     CSS/CSSSupportsRule.cpp
     CSS/CSSTransition.cpp
+    CSS/CSSUnparsedValue.cpp
+    CSS/CSSVariableReferenceValue.cpp
     CSS/Descriptor.cpp
     CSS/Display.cpp
     CSS/EdgeRect.cpp

Libraries/LibWeb/CSS/CSSUnparsedValue.cpp

@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "CSSUnparsedValue.h"
+#include <LibWeb/Bindings/CSSUnparsedValuePrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/CSS/CSSVariableReferenceValue.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::CSS {
+
+GC_DEFINE_ALLOCATOR(CSSUnparsedValue);
+
+GC::Ref<CSSUnparsedValue> CSSUnparsedValue::create(JS::Realm& realm, Vector<GCRootCSSUnparsedSegment> value)
+{
+    // NB: Convert our GC::Roots into GC::Refs.
+    Vector<CSSUnparsedSegment> converted_value;
+    for (auto const& variant : value) {
+        variant.visit(
+            [&](GC::Root<CSSVariableReferenceValue> const& it) { converted_value.append(GC::Ref { *it }); },
+            [&](String const& it) { converted_value.append(it); });
+    }
+
+    return realm.create<CSSUnparsedValue>(realm, move(converted_value));
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssunparsedvalue-cssunparsedvalue
+WebIDL::ExceptionOr<GC::Ref<CSSUnparsedValue>> CSSUnparsedValue::construct_impl(JS::Realm& realm, Vector<GCRootCSSUnparsedSegment> value)
+{
+    // AD-HOC: There is no spec for this, see https://github.com/w3c/css-houdini-drafts/issues/1146
+
+    return CSSUnparsedValue::create(realm, move(value));
+}
+
+CSSUnparsedValue::CSSUnparsedValue(JS::Realm& realm, Vector<CSSUnparsedSegment> value)
+    : CSSStyleValue(realm)
+    , m_tokens(move(value))
+{
+    m_legacy_platform_object_flags = LegacyPlatformObjectFlags {
+        .supports_indexed_properties = true,
+        .has_indexed_property_setter = true,
+    };
+}
+
+CSSUnparsedValue::~CSSUnparsedValue() = default;
+
+void CSSUnparsedValue::initialize(JS::Realm& realm)
+{
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(CSSUnparsedValue);
+    Base::initialize(realm);
+}
+
+void CSSUnparsedValue::visit_edges(Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    for (auto const& token : m_tokens) {
+        if (auto* variable = token.get_pointer<GC::Ref<CSSVariableReferenceValue>>()) {
+            visitor.visit(*variable);
+        }
+    }
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssunparsedvalue-length
+WebIDL::UnsignedLong CSSUnparsedValue::length() const
+{
+    // The length attribute returns the size of the [[tokens]] internal slot.
+    return m_tokens.size();
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#ref-for-dfn-determine-the-value-of-an-indexed-property
+Optional<JS::Value> CSSUnparsedValue::item_value(size_t index) const
+{
+    // To determine the value of an indexed property of a CSSUnparsedValue this and an index n, let tokens be this’s
+    // [[tokens]] internal slot, and return tokens[n].
+    if (index >= m_tokens.size())
+        return {};
+    auto value = m_tokens[index];
+    return value.visit(
+        [&](GC::Ref<CSSVariableReferenceValue> const& variable) -> JS::Value { return variable; },
+        [&](String const& string) -> JS::Value { return JS::PrimitiveString::create(vm(), string); });
+}
+
+static WebIDL::ExceptionOr<CSSUnparsedSegment> unparsed_segment_from_js_value(JS::VM& vm, JS::Value& value)
+{
+    if (value.is_object()) {
+        if (auto* variable_reference = as_if<CSSVariableReferenceValue>(value.as_object())) {
+            return GC::Ref { *variable_reference };
+        }
+    }
+    return TRY(value.to_string(vm));
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#ref-for-dfn-set-the-value-of-an-existing-indexed-property
+WebIDL::ExceptionOr<void> CSSUnparsedValue::set_value_of_existing_indexed_property(u32 n, JS::Value value)
+{
+    // To set the value of an existing indexed property of a CSSUnparsedValue this, an index n, and a value new value,
+    // let tokens be this’s [[tokens]] internal slot, and set tokens[n] to new value.
+    m_tokens[n] = TRY(unparsed_segment_from_js_value(vm(), value));
+    return {};
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#ref-for-dfn-set-the-value-of-a-new-indexed-property
+WebIDL::ExceptionOr<void> CSSUnparsedValue::set_value_of_new_indexed_property(u32 n, JS::Value value)
+{
+    // To set the value of a new indexed property of a CSSUnparsedValue this, an index n, and a value new value,
+    // let tokens be this’s [[tokens]] internal slot. If n is not equal to the size of tokens, throw a RangeError.
+    // Otherwise, append new value to tokens.
+    if (n != m_tokens.size())
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::RangeError, "Index out of range"sv };
+
+    m_tokens.append(TRY(unparsed_segment_from_js_value(vm(), value)));
+    return {};
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#serialize-a-cssunparsedvalue
+String CSSUnparsedValue::to_string() const
+{
+    // To serialize a CSSUnparsedValue this:
+    // 1. Let s initially be the empty string.
+    StringBuilder s;
+
+    // 2. For each item in this’s [[tokens]] internal slot:
+    for (auto const& item : m_tokens) {
+        // FIXME: In order to match the expected test behaviour, this should insert comments, with the same rules as
+        //        serialize_a_series_of_component_values(). See https://github.com/w3c/css-houdini-drafts/issues/1148
+        item.visit(
+            // 1. If item is a USVString, append it to s.
+            [&](String const& string) {
+                s.append(string);
+            },
+            // 2. Otherwise, item is a CSSVariableReferenceValue. Serialize it, then append the result to s.
+            [&](GC::Ref<CSSVariableReferenceValue> const& variable) {
+                s.append(variable->to_string());
+            });
+    }
+
+    // 3. Return s.
+    return s.to_string_without_validation();
+}
+
+}

Libraries/LibWeb/CSS/CSSUnparsedValue.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/CSS/CSSStyleValue.h>
+#include <LibWeb/WebIDL/Types.h>
+
+namespace Web::CSS {
+
+using CSSUnparsedSegment = Variant<String, GC::Ref<CSSVariableReferenceValue>>;
+using GCRootCSSUnparsedSegment = Variant<String, GC::Root<CSSVariableReferenceValue>>;
+
+// https://drafts.css-houdini.org/css-typed-om-1/#cssunparsedvalue
+class CSSUnparsedValue : public CSSStyleValue {
+    WEB_PLATFORM_OBJECT(CSSUnparsedValue, CSSStyleValue);
+    GC_DECLARE_ALLOCATOR(CSSUnparsedValue);
+
+public:
+    [[nodiscard]] static GC::Ref<CSSUnparsedValue> create(JS::Realm&, Vector<GCRootCSSUnparsedSegment>);
+    static WebIDL::ExceptionOr<GC::Ref<CSSUnparsedValue>> construct_impl(JS::Realm&, Vector<GCRootCSSUnparsedSegment>);
+
+    virtual ~CSSUnparsedValue() override;
+
+    WebIDL::UnsignedLong length() const;
+    virtual Optional<JS::Value> item_value(size_t index) const override;
+    virtual WebIDL::ExceptionOr<void> set_value_of_existing_indexed_property(u32, JS::Value) override;
+    virtual WebIDL::ExceptionOr<void> set_value_of_new_indexed_property(u32, JS::Value) override;
+
+    virtual String to_string() const override;
+
+private:
+    explicit CSSUnparsedValue(JS::Realm&, Vector<CSSUnparsedSegment>);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Visitor&) override;
+
+    // https://drafts.css-houdini.org/css-typed-om-1/#dom-cssunparsedvalue-tokens-slot
+    // They have a [[tokens]] internal slot, which is a list of USVStrings and CSSVariableReferenceValue objects.
+    // This list is the object’s values to iterate over.
+    Vector<CSSUnparsedSegment> m_tokens;
+};
+
+}

Libraries/LibWeb/CSS/CSSUnparsedValue.idl

@@ -0,0 +1,16 @@
+#import <CSS/CSSStyleValue.idl>
+#import <CSS/CSSVariableReferenceValue.idl>
+
+// https://drafts.css-houdini.org/css-typed-om-1/#cssunparsedvalue
+[Exposed=(Window, Worker, PaintWorklet, LayoutWorklet)]
+interface CSSUnparsedValue : CSSStyleValue {
+    constructor(sequence<CSSUnparsedSegment> members);
+    readonly attribute unsigned long length;
+    getter CSSUnparsedSegment (unsigned long index);
+    setter undefined (unsigned long index, CSSUnparsedSegment val);
+    // FIXME: Different order from the spec, because our IDL parser needs the indexed getter to be defined already.
+    iterable<CSSUnparsedSegment>;
+};
+
+// https://drafts.css-houdini.org/css-typed-om-1/#typedefdef-cssunparsedsegment
+typedef (USVString or CSSVariableReferenceValue) CSSUnparsedSegment;

Libraries/LibWeb/CSS/CSSVariableReferenceValue.cpp

@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "CSSVariableReferenceValue.h"
+#include <LibWeb/Bindings/CSSVariableReferenceValuePrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/CSS/CSSUnparsedValue.h>
+#include <LibWeb/CSS/PropertyName.h>
+#include <LibWeb/HTML/CustomElements/CustomElementName.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::CSS {
+
+GC_DEFINE_ALLOCATOR(CSSVariableReferenceValue);
+GC::Ref<CSSVariableReferenceValue> CSSVariableReferenceValue::create(JS::Realm& realm, FlyString variable, GC::Ptr<CSSUnparsedValue> fallback)
+{
+    return realm.create<CSSVariableReferenceValue>(realm, move(variable), move(fallback));
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssvariablereferencevalue-cssvariablereferencevalue
+WebIDL::ExceptionOr<GC::Ref<CSSVariableReferenceValue>> CSSVariableReferenceValue::construct_impl(JS::Realm& realm, FlyString variable, GC::Ptr<CSSUnparsedValue> fallback)
+{
+    // The CSSVariableReferenceValue(variable, fallback) constructor must, when called, perform the following steps:
+    // 1. If variable is not a custom property name string, throw a TypeError.
+    if (!is_a_custom_property_name_string(variable))
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, MUST(String::formatted("'{}' is not a valid CSS custom property name", variable)) };
+
+    // 2. Return a new CSSVariableReferenceValue with its variable internal slot set to variable and its fallback internal slot set to fallback.
+    return CSSVariableReferenceValue::create(realm, move(variable), move(fallback));
+}
+
+CSSVariableReferenceValue::CSSVariableReferenceValue(JS::Realm& realm, FlyString variable, GC::Ptr<CSSUnparsedValue> fallback)
+    : Bindings::PlatformObject(realm)
+    , m_variable(move(variable))
+    , m_fallback(move(fallback))
+{
+}
+
+CSSVariableReferenceValue::~CSSVariableReferenceValue() = default;
+
+void CSSVariableReferenceValue::initialize(JS::Realm& realm)
+{
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(CSSVariableReferenceValue);
+    Base::initialize(realm);
+}
+
+void CSSVariableReferenceValue::visit_edges(Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_fallback);
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssvariablereferencevalue-variable
+String CSSVariableReferenceValue::variable() const
+{
+    // The getter for the variable attribute of a CSSVariableReferenceValue this must return its variable internal slot.
+    return m_variable.to_string();
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssvariablereferencevalue-variable
+WebIDL::ExceptionOr<void> CSSVariableReferenceValue::set_variable(FlyString variable)
+{
+    // The variable attribute of a CSSVariableReferenceValue this must, on setting a variable variable, perform the following steps:
+    // 1. If variable is not a custom property name string, throw a TypeError.
+    if (!is_a_custom_property_name_string(variable))
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, MUST(String::formatted("'{}' is not a valid CSS custom property name", variable)) };
+
+    // 2. Otherwise, set this’s variable internal slot to variable.
+    m_variable = move(variable);
+    return {};
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssvariablereferencevalue-fallback
+GC::Ptr<CSSUnparsedValue> CSSVariableReferenceValue::fallback() const
+{
+    // AD-HOC: No spec algorithm, see https://github.com/w3c/css-houdini-drafts/issues/1146#issuecomment-3188550133
+    return m_fallback;
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssvariablereferencevalue-fallback
+WebIDL::ExceptionOr<void> CSSVariableReferenceValue::set_fallback(GC::Ptr<CSSUnparsedValue> fallback)
+{
+    // AD-HOC: No spec algorithm, see https://github.com/w3c/css-houdini-drafts/issues/1146#issuecomment-3188550133
+    m_fallback = move(fallback);
+    return {};
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#serialize-a-cssvariablereferencevalue
+String CSSVariableReferenceValue::to_string() const
+{
+    // To serialize a CSSVariableReferenceValue this:
+    // 1. Let s initially be "var(".
+    StringBuilder s;
+    s.append("var("sv);
+
+    // 2. Append this’s variable internal slot to s.
+    s.append(m_variable);
+
+    // 3. If this’s fallback internal slot is not null, append ", " to s, then serialize the fallback internal slot and append it to s.
+    if (m_fallback) {
+        // AD-HOC: Tested behaviour requires we append "," without the space. https://github.com/w3c/css-houdini-drafts/issues/1148
+        s.append(","sv);
+        s.append(m_fallback->to_string());
+    }
+
+    // 4. Append ")" to s and return s.
+    s.append(")"sv);
+    return s.to_string_without_validation();
+}
+
+}

Libraries/LibWeb/CSS/CSSVariableReferenceValue.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/FlyString.h>
+#include <LibWeb/Bindings/PlatformObject.h>
+
+namespace Web::CSS {
+
+class CSSVariableReferenceValue : public Bindings::PlatformObject {
+    WEB_PLATFORM_OBJECT(CSSVariableReferenceValue, Bindings::PlatformObject);
+    GC_DECLARE_ALLOCATOR(CSSVariableReferenceValue);
+
+public:
+    [[nodiscard]] static GC::Ref<CSSVariableReferenceValue> create(JS::Realm&, FlyString variable, GC::Ptr<CSSUnparsedValue> fallback = nullptr);
+    static WebIDL::ExceptionOr<GC::Ref<CSSVariableReferenceValue>> construct_impl(JS::Realm&, FlyString variable, GC::Ptr<CSSUnparsedValue> fallback);
+
+    virtual ~CSSVariableReferenceValue() override;
+
+    String variable() const;
+    WebIDL::ExceptionOr<void> set_variable(FlyString);
+
+    GC::Ptr<CSSUnparsedValue> fallback() const;
+    WebIDL::ExceptionOr<void> set_fallback(GC::Ptr<CSSUnparsedValue>);
+
+    String to_string() const;
+
+private:
+    CSSVariableReferenceValue(JS::Realm&, FlyString variable, GC::Ptr<CSSUnparsedValue> fallback);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Visitor&) override;
+
+    FlyString m_variable;
+    GC::Ptr<CSSUnparsedValue> m_fallback;
+};
+
+}

Libraries/LibWeb/CSS/CSSVariableReferenceValue.idl

@@ -0,0 +1,9 @@
+#import <CSS/CSSUnparsedValue.idl>
+
+// https://drafts.css-houdini.org/css-typed-om-1/#cssvariablereferencevalue
+[Exposed=(Window, Worker, PaintWorklet, LayoutWorklet)]
+interface CSSVariableReferenceValue {
+    constructor(USVString variable, optional CSSUnparsedValue? fallback = null);
+    attribute USVString variable;
+    readonly attribute CSSUnparsedValue? fallback;
+};

Libraries/LibWeb/Forward.h

@@ -256,6 +256,8 @@ class CSSStyleRule;
 class CSSStyleSheet;
 class CSSStyleValue;
 class CSSSupportsRule;
+class CSSUnparsedValue;
+class CSSVariableReferenceValue;
 class CursorStyleValue;
 class CustomIdentStyleValue;
 class DimensionStyleValue;

Libraries/LibWeb/idl_files.cmake

@@ -52,6 +52,8 @@ libweb_js_bindings(CSS/CSSStyleSheet)
 libweb_js_bindings(CSS/CSSStyleValue)
 libweb_js_bindings(CSS/CSSSupportsRule)
 libweb_js_bindings(CSS/CSSTransition)
+libweb_js_bindings(CSS/CSSUnparsedValue)
+libweb_js_bindings(CSS/CSSVariableReferenceValue)
 libweb_js_bindings(CSS/FontFace)
 libweb_js_bindings(CSS/FontFaceSet)
 libweb_js_bindings(CSS/MediaList)

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

@@ -56,6 +56,8 @@ static bool is_platform_object(Type const& type)
         "CryptoKey"sv,
         "CSSKeywordValue"sv,
         "CSSStyleValue"sv,
+        "CSSUnparsedValue"sv,
+        "CSSVariableReferenceValue"sv,
         "CustomStateSet"sv,
         "DataTransfer"sv,
         "Document"sv,

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

@@ -64,6 +64,8 @@ CSSStyleSheet
 CSSStyleValue
 CSSSupportsRule
 CSSTransition
+CSSUnparsedValue
+CSSVariableReferenceValue
 CacheStorage
 CanvasGradient
 CanvasPattern

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-normalization/normalize-tokens.tentative.txt

@@ -1,3 +1,21 @@
-Harness status: Error
+Harness status: OK
 
-Found 0 tests
+Found 16 tests
+
+16 Fail
+Fail	Normalizing "var(--A)" on a CSS property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A)" on a shorthand returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A)" on a list-valued property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A)" on a custom property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, 1em)" on a CSS property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, 1em)" on a shorthand returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, 1em)" on a list-valued property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, 1em)" on a custom property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, var(--B))" on a CSS property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, var(--B))" on a shorthand returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, var(--B))" on a list-valued property returns correct CSSUnparsedValue
+Fail	Normalizing "var(--A, var(--B))" on a custom property returns correct CSSUnparsedValue
+Fail	Normalizing "calc(42px + var(--foo, 15em) + var(--bar, var(--far) + 15px))" on a CSS property returns correct CSSUnparsedValue
+Fail	Normalizing "calc(42px + var(--foo, 15em) + var(--bar, var(--far) + 15px))" on a shorthand returns correct CSSUnparsedValue
+Fail	Normalizing "calc(42px + var(--foo, 15em) + var(--bar, var(--far) + 15px))" on a list-valued property returns correct CSSUnparsedValue
+Fail	Normalizing "calc(42px + var(--foo, 15em) + var(--bar, var(--far) + 15px))" on a custom property returns correct CSSUnparsedValue

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-serialization/cssUnparsedValue.txt

@@ -2,9 +2,10 @@ Harness status: OK
 
 Found 5 tests
 
-5 Fail
+2 Pass
+3 Fail
 Fail	CSSUnparsedValue containing strings serializes to its tokenized contents
-Fail	CSSUnparsedValue containing variable references serializes its tokenized contents
+Pass	CSSUnparsedValue containing variable references serializes its tokenized contents
 Fail	CSSUnparsedValue containing mix of strings and variable references serializes to its tokenized contents
-Fail	CSSUnparsedValue can hold same object in multiple places
+Pass	CSSUnparsedValue can hold same object in multiple places
 Fail	attributeStyleMap round-trips correctly, though the comment is gone

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssUnparsedValue-empty.txt

@@ -2,5 +2,5 @@ Harness status: OK
 
 Found 1 tests
 
-1 Fail
-Fail	Don't crash when serializing empty CSSUnparsedValue
+1 Pass
+Pass	Don't crash when serializing empty CSSUnparsedValue

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssUnparsedValue-indexed-getter-setter.txt

@@ -2,10 +2,10 @@ Harness status: OK
 
 Found 6 tests
 
-6 Fail
-Fail	Getting invalid index in CSSUnparsedValue returns undefined
-Fail	Can update fragment in CSSUnparsedValue to a String
-Fail	Can update fragment in CSSUnparsedValue to a CSSVariableReference
-Fail	Setting one past the last fragment in a CSSUnparsedValue to a String appends the new fragment
-Fail	Setting one past the last fragment in a CSSUnparsedValue to a CSSVariableReferenceValue appends the new fragment
-Fail	Setting out of range index in CSSUnparsedValue throws RangeError
+6 Pass
+Pass	Getting invalid index in CSSUnparsedValue returns undefined
+Pass	Can update fragment in CSSUnparsedValue to a String
+Pass	Can update fragment in CSSUnparsedValue to a CSSVariableReference
+Pass	Setting one past the last fragment in a CSSUnparsedValue to a String appends the new fragment
+Pass	Setting one past the last fragment in a CSSUnparsedValue to a CSSVariableReferenceValue appends the new fragment
+Pass	Setting out of range index in CSSUnparsedValue throws RangeError

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssUnparsedValue-iterable.txt

@@ -2,6 +2,6 @@ Harness status: OK
 
 Found 2 tests
 
-2 Fail
-Fail	Iterating over an empty CSSUnparsedValue produces nothing
-Fail	Iterating over a CSSUnparsedValue produces all fragments
+2 Pass
+Pass	Iterating over an empty CSSUnparsedValue produces nothing
+Pass	Iterating over a CSSUnparsedValue produces all fragments

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssUnparsedValue-length.txt

@@ -2,8 +2,8 @@ Harness status: OK
 
 Found 4 tests
 
-4 Fail
-Fail	Length of CSSUnparsedValue with no fragments is zero
-Fail	Length of CSSUnparsedValue with multiple fragments is the number of fragments
-Fail	Length of CSSUnparsedValue updates when fragments are appended
-Fail	Length of CSSUnparsedValue does not change when fragments are modified
+4 Pass
+Pass	Length of CSSUnparsedValue with no fragments is zero
+Pass	Length of CSSUnparsedValue with multiple fragments is the number of fragments
+Pass	Length of CSSUnparsedValue updates when fragments are appended
+Pass	Length of CSSUnparsedValue does not change when fragments are modified

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssUnparsedValue.txt

@@ -1,3 +1,9 @@
-Harness status: Error
+Harness status: OK
 
-Found 0 tests
+Found 4 tests
+
+4 Pass
+Pass	CSSUnparsedValue can be constructed from no arguments
+Pass	CSSUnparsedValue can be constructed from a single empty string
+Pass	CSSUnparsedValue can be constructed from a single CSSVariableReferenceValue
+Pass	CSSUnparsedValue can be constructed from a mix of strings and CSSVariableReferenceValues

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssVariableReferenceValue-invalid.txt

@@ -2,6 +2,6 @@ Harness status: OK
 
 Found 2 tests
 
-2 Fail
-Fail	Constructing a CSSVariableReferenceValue with an empty variable name throws a TypeError
-Fail	Constructing a CSSVariableReferenceValue with an invalid variable name throws SyntaxError
+2 Pass
+Pass	Constructing a CSSVariableReferenceValue with an empty variable name throws a TypeError
+Pass	Constructing a CSSVariableReferenceValue with an invalid variable name throws SyntaxError

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssVariableReferenceValue-variable.txt

@@ -2,7 +2,7 @@ Harness status: OK
 
 Found 3 tests
 
-3 Fail
-Fail	CSSVariableReferenceValue.variable can updated to a valid custom property name
-Fail	Updating CSSVariableReferenceValue.variable to the empty string throws TypeError
-Fail	Updating CSSVariableReferenceValue.variable to an invalid custom property name throws TypeError
+3 Pass
+Pass	CSSVariableReferenceValue.variable can updated to a valid custom property name
+Pass	Updating CSSVariableReferenceValue.variable to the empty string throws TypeError
+Pass	Updating CSSVariableReferenceValue.variable to an invalid custom property name throws TypeError

Tests/LibWeb/Text/expected/wpt-import/css/css-typed-om/stylevalue-subclasses/cssVariableReferenceValue.txt

@@ -2,7 +2,7 @@ Harness status: OK
 
 Found 3 tests
 
-3 Fail
-Fail	CSSVariableReferenceValue can be constructed with no fallback
-Fail	CSSVariableReferenceValue can be constructed with null fallback
-Fail	CSSVariableReferenceValue can be constructed with valid fallback
+3 Pass
+Pass	CSSVariableReferenceValue can be constructed with no fallback
+Pass	CSSVariableReferenceValue can be constructed with null fallback
+Pass	CSSVariableReferenceValue can be constructed with valid fallback