LibWeb/CSS: Implement CSSStyleValue.parse() and .parseAll()

The "subdivide into iterations" part is left as a FIXME for now, until
we have a way of knowing if a property is a list or not.

The parse_a_css_style_value() helper has an unwieldy return type because
of the requirement that it return either one value or a list of values,
but sticking to the spec here seems worthwhile for now.

Libraries/LibWeb/CSS/CSSStyleValue.cpp

@@ -7,6 +7,8 @@
 #include "CSSStyleValue.h"
 #include <LibWeb/Bindings/CSSStyleValuePrototype.h>
 #include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/CSS/Parser/Parser.h>
+#include <LibWeb/CSS/PropertyName.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
 
 namespace Web::CSS {
@@ -36,6 +38,59 @@ void CSSStyleValue::initialize(JS::Realm& realm)
     Base::initialize(realm);
 }
 
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssstylevalue-parse
+WebIDL::ExceptionOr<GC::Ref<CSSStyleValue>> CSSStyleValue::parse(JS::VM& vm, String property, String css_text)
+{
+    // The parse(property, cssText) method, when invoked, must parse a CSSStyleValue with property property, cssText
+    // cssText, and parseMultiple set to false, and return the result.
+    auto result = parse_a_css_style_value(vm, property, css_text, ParseMultiple::No);
+    if (result.is_exception())
+        return result.release_error();
+    return result.value().get<GC::Ref<CSSStyleValue>>();
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#dom-cssstylevalue-parseall
+WebIDL::ExceptionOr<GC::RootVector<GC::Ref<CSSStyleValue>>> CSSStyleValue::parse_all(JS::VM& vm, String property, String css_text)
+{
+    // The parseAll(property, cssText) method, when invoked, must parse a CSSStyleValue with property property, cssText
+    // cssText, and parseMultiple set to true, and return the result.
+    auto result = parse_a_css_style_value(vm, property, css_text, ParseMultiple::Yes);
+    if (result.is_exception())
+        return result.release_error();
+    return result.value().get<GC::RootVector<GC::Ref<CSSStyleValue>>>();
+}
+
+// https://drafts.css-houdini.org/css-typed-om-1/#parse-a-cssstylevalue
+WebIDL::ExceptionOr<Variant<GC::Ref<CSSStyleValue>, GC::RootVector<GC::Ref<CSSStyleValue>>>> CSSStyleValue::parse_a_css_style_value(JS::VM& vm, String property, String css_text, ParseMultiple parse_multiple)
+{
+    // 1. If property is not a custom property name string, set property to property ASCII lowercased.
+    if (!is_a_custom_property_name_string(property))
+        property = property.to_ascii_lowercase();
+
+    // 2. If property is not a valid CSS property, throw a TypeError.
+    if (!is_a_valid_css_property(property))
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, MUST(String::formatted("'{}' is not a valid CSS property", property)) };
+
+    // 3. Attempt to parse cssText according to property’s grammar.
+    //    If this fails, throw a TypeError.
+    //    Otherwise, let whole value be the parsed result.
+    auto property_id = property_id_from_string(property).release_value();
+    auto whole_value = parse_css_value(Parser::ParsingParams {}, css_text, property_id);
+    if (!whole_value)
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, MUST(String::formatted("Failed to parse '{}' as a value for '{}' property", css_text, property)) };
+
+    // FIXME: 4. Subdivide into iterations whole value, according to property, and let values be the result.
+
+    // 5. For each value in values, replace it with the result of reifying value for property.
+    GC::RootVector<GC::Ref<CSSStyleValue>> reified_values { vm.heap() };
+    reified_values.append(whole_value->reify(*vm.current_realm(), property));
+
+    // 6. If parseMultiple is false, return values[0]. Otherwise, return values.
+    if (parse_multiple == ParseMultiple::No)
+        return reified_values.take_first();
+    return reified_values;
+}
+
 // https://drafts.css-houdini.org/css-typed-om-1/#stylevalue-serialization
 String CSSStyleValue::to_string() const
 {

Libraries/LibWeb/CSS/CSSStyleValue.h

@@ -22,6 +22,9 @@ public:
 
     virtual void initialize(JS::Realm&) override;
 
+    static WebIDL::ExceptionOr<GC::Ref<CSSStyleValue>> parse(JS::VM&, String property, String css_text);
+    static WebIDL::ExceptionOr<GC::RootVector<GC::Ref<CSSStyleValue>>> parse_all(JS::VM&, String property, String css_text);
+
     virtual String to_string() const;
 
 protected:
@@ -30,6 +33,12 @@ protected:
 private:
     explicit CSSStyleValue(JS::Realm&, String associated_property, String constructed_from_string);
 
+    enum class ParseMultiple : u8 {
+        No,
+        Yes,
+    };
+    static WebIDL::ExceptionOr<Variant<GC::Ref<CSSStyleValue>, GC::RootVector<GC::Ref<CSSStyleValue>>>> parse_a_css_style_value(JS::VM&, String property, String css_text, ParseMultiple);
+
     // https://drafts.css-houdini.org/css-typed-om-1/#dom-cssstylevalue-associatedproperty-slot
     Optional<String> m_associated_property;
 

Libraries/LibWeb/CSS/CSSStyleValue.idl

@@ -2,6 +2,6 @@
 [Exposed=(Window, Worker, PaintWorklet, LayoutWorklet)]
 interface CSSStyleValue {
     stringifier;
-    [FIXME, Exposed=Window] static CSSStyleValue parse(USVString property, USVString cssText);
+    [Exposed=Window] static CSSStyleValue parse(USVString property, USVString cssText);
-    [FIXME, Exposed=Window] static sequence<CSSStyleValue> parseAll(USVString property, USVString cssText);
+    [Exposed=Window] static sequence<CSSStyleValue> parseAll(USVString property, USVString cssText);
 };

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

@@ -2,7 +2,6 @@ Harness status: OK
 
 Found 2 tests
 
-1 Pass
+2 Pass
-1 Fail
+Pass	CSS identifiers are normalized from String to CSSKeywordValues
-Fail	CSS identifiers are normalized from String to CSSKeywordValues
 Pass	CSS identifiers are normalized from CSSOM to CSSKeywordValues

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

@@ -2,9 +2,9 @@ Harness status: OK
 
 Found 5 tests
 
-5 Fail
+5 Pass
-Fail	CSSStyleValue.parse() with a valid property returns a CSSStyleValue
+Pass	CSSStyleValue.parse() with a valid property returns a CSSStyleValue
-Fail	CSSStyleValue.parse() is not case sensitive
+Pass	CSSStyleValue.parse() is not case sensitive
-Fail	CSSStyleValue.parse() with a valid list-valued property returns a CSSStyleValue
+Pass	CSSStyleValue.parse() with a valid list-valued property returns a CSSStyleValue
-Fail	CSSStyleValue.parse() with a valid shorthand property returns a CSSStyleValue
+Pass	CSSStyleValue.parse() with a valid shorthand property returns a CSSStyleValue
-Fail	CSSStyleValue.parse() with a valid custom property returns a CSSStyleValue
+Pass	CSSStyleValue.parse() with a valid custom property returns a CSSStyleValue

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

@@ -2,9 +2,10 @@ Harness status: OK
 
 Found 5 tests
 
-5 Fail
+4 Pass
-Fail	CSSStyleValue.parseAll() with a valid property returns a list with a single CSSStyleValue
+1 Fail
-Fail	CSSStyleValue.parseAll() is not case sensitive
+Pass	CSSStyleValue.parseAll() with a valid property returns a list with a single CSSStyleValue
+Pass	CSSStyleValue.parseAll() is not case sensitive
 Fail	CSSStyleValue.parseAll() with a valid list-valued property returns a list with a single CSSStyleValue
-Fail	CSSStyleValue.parseAll() with a valid shorthand property returns a CSSStyleValue
+Pass	CSSStyleValue.parseAll() with a valid shorthand property returns a CSSStyleValue
-Fail	CSSStyleValue.parseAll() with a valid custom property returns a list with a single CSSStyleValue
+Pass	CSSStyleValue.parseAll() with a valid custom property returns a list with a single CSSStyleValue

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

@@ -2,9 +2,8 @@ Harness status: OK
 
 Found 4 tests
 
-3 Pass
+4 Pass
-1 Fail
 Pass	CSSKeywordValue constructed from IDL serializes correctly
 Pass	CSSKeywordValue constructed from IDL serializes to escaped strings
-Fail	CSSKeywordValue from DOMString modified through "value" setter serializes correctly
+Pass	CSSKeywordValue from DOMString modified through "value" setter serializes correctly
 Pass	CSSKeywordValue from CSSOM modified through "value" setter serializes correctly

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

@@ -2,6 +2,6 @@ Harness status: OK
 
 Found 2 tests
 
-2 Fail
+2 Pass
-Fail	CSSStyleValue parsed from string serializes to given string
+Pass	CSSStyleValue parsed from string serializes to given string
-Fail	Shorthand CSSStyleValue parsed from string serializes to given string
+Pass	Shorthand CSSStyleValue parsed from string serializes to given string