LibWeb: Implement text-decoration: spelling-error and grammar-error

Author: https://github.com/AtkinsSJ
Commit: 532c01c388
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3724

Libraries/LibWeb/CSS/ComputedProperties.cpp

@@ -1008,8 +1008,11 @@ Vector<TextDecorationLine> ComputedProperties::text_decoration_line() const
         return lines;
     }
 
-    if (value.is_keyword() && value.to_keyword() == Keyword::None)
-        return {};
+    if (value.is_keyword()) {
+        if (value.to_keyword() == Keyword::None)
+            return {};
+        return { keyword_to_text_decoration_line(value.to_keyword()).release_value() };
+    }
 
     dbgln("FIXME: Unsupported value for text-decoration-line: {}", value.to_string(CSSStyleValue::SerializationMode::Normal));
     return {};

Libraries/LibWeb/CSS/Enums.json

@@ -545,7 +545,9 @@
     "underline",
     "overline",
     "line-through",
-    "blink"
+    "blink",
+    "spelling-error",
+    "grammar-error"
   ],
   "text-decoration-style": [
     "dashed",

Libraries/LibWeb/CSS/Keywords.json

@@ -190,6 +190,7 @@
   "fullscreen",
   "grab",
   "grabbing",
+  "grammar-error",
   "graytext",
   "grid",
   "groove",
@@ -404,6 +405,7 @@
   "space-around",
   "space-between",
   "space-evenly",
+  "spelling-error",
   "square",
   "square-button",
   "srgb",

Libraries/LibWeb/CSS/Parser/PropertyParsing.cpp

@@ -3510,6 +3510,8 @@ RefPtr<CSSStyleValue> Parser::parse_text_decoration_line_value(TokenStream<Compo
 {
     StyleValueVector style_values;
 
+    bool includes_spelling_or_grammar_error_value = false;
+
     while (tokens.has_next_token()) {
         auto maybe_value = parse_css_value_for_property(PropertyID::TextDecorationLine, tokens);
         if (!maybe_value)
@@ -3522,6 +3524,9 @@ RefPtr<CSSStyleValue> Parser::parse_text_decoration_line_value(TokenStream<Compo
                     break;
                 return value;
             }
+            if (first_is_one_of(*maybe_line, TextDecorationLine::SpellingError, TextDecorationLine::GrammarError)) {
+                includes_spelling_or_grammar_error_value = true;
+            }
             if (style_values.contains_slow(value))
                 break;
             style_values.append(move(value));
@@ -3534,6 +3539,13 @@ RefPtr<CSSStyleValue> Parser::parse_text_decoration_line_value(TokenStream<Compo
     if (style_values.is_empty())
         return nullptr;
 
+    // These can only appear on their own.
+    if (style_values.size() > 1 && includes_spelling_or_grammar_error_value)
+        return nullptr;
+
+    if (style_values.size() == 1)
+        return *style_values.first();
+
     quick_sort(style_values, [](auto& left, auto& right) {
         return *keyword_to_text_decoration_line(left->to_keyword()) < *keyword_to_text_decoration_line(right->to_keyword());
     });