Everywhere: Avoid calling from_utf8 on FlyString or String

We already have a String :^)

Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp

@@ -2283,7 +2283,7 @@ RefPtr<StyleValue> Parser::parse_ratio_value(TokenStream<ComponentValue>& tokens
 RefPtr<StyleValue> Parser::parse_string_value(ComponentValue const& component_value)
 {
     if (component_value.is(Token::Type::String))
-        return StringStyleValue::create(MUST(String::from_utf8(component_value.token().string())));
+        return StringStyleValue::create(component_value.token().string().to_string());
 
     return nullptr;
 }
@@ -4099,7 +4099,7 @@ RefPtr<StyleValue> Parser::parse_font_family_value(TokenStream<ComponentValue>&
             (void)tokens.next_token(); // String
             if (!next_is_comma_or_eof())
                 return nullptr;
-            font_families.append(StringStyleValue::create(MUST(String::from_utf8(peek.token().string()))));
+            font_families.append(StringStyleValue::create(peek.token().string().to_string()));
             (void)tokens.next_token(); // Comma
             continue;
         }
@@ -5178,10 +5178,7 @@ Optional<CSS::GridRepeat> Parser::parse_repeat(Vector<ComponentValue> const& com
             TokenStream block_tokens { token.block().values() };
             while (block_tokens.has_next_token()) {
                 auto current_block_token = block_tokens.next_token();
-                auto maybe_string = String::from_utf8(current_block_token.token().ident());
-                if (maybe_string.is_error())
-                    return {};
-                line_names.append(maybe_string.value());
+                line_names.append(current_block_token.token().ident().to_string());
                 block_tokens.skip_whitespace();
             }
             line_names_list.append(line_names);
@@ -5289,10 +5286,7 @@ RefPtr<StyleValue> Parser::parse_grid_track_size_list(Vector<ComponentValue> con
             block_tokens.skip_whitespace();
             while (block_tokens.has_next_token()) {
                 auto current_block_token = block_tokens.next_token();
-                auto maybe_string = String::from_utf8(current_block_token.token().ident());
-                if (maybe_string.is_error())
-                    return nullptr;
-                line_names.append(maybe_string.value());
+                line_names.append(current_block_token.token().ident().to_string());
                 block_tokens.skip_whitespace();
             }
             line_names_list.append(line_names);
@@ -5415,11 +5409,8 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement(Vector<ComponentValue> con
             return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_span(1));
         if (is_valid_integer(current_token))
             return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line(static_cast<int>(current_token.token().number_value()), {}));
-        if (is_identifier(current_token)) {
-            auto maybe_string = String::from_utf8(current_token.token().ident());
-            if (!maybe_string.is_error())
-                return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line({}, maybe_string.value()));
-        }
+        if (is_identifier(current_token))
+            return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line({}, current_token.token().to_string()));
         return nullptr;
     }
 
@@ -5443,10 +5434,7 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement(Vector<ComponentValue> con
         }
         if (is_identifier(current_token)) {
             if (identifier_value.is_empty()) {
-                auto maybe_string = String::from_utf8(current_token.token().ident());
-                if (maybe_string.is_error())
-                    return nullptr;
-                identifier_value = maybe_string.release_value();
+                identifier_value = current_token.token().ident().to_string();
             } else {
                 return nullptr;
             }
@@ -5666,7 +5654,7 @@ RefPtr<StyleValue> Parser::parse_grid_template_areas_value(TokenStream<Component
     auto transaction = tokens.begin_transaction();
     while (tokens.has_next_token() && tokens.peek_token().is(Token::Type::String)) {
         Vector<String> grid_area_columns;
-        auto const parts = MUST(MUST(String::from_utf8(tokens.next_token().token().string())).split(' '));
+        auto const parts = MUST(tokens.next_token().token().string().to_string().split(' '));
         for (auto& part : parts) {
             grid_area_columns.append(part);
         }
@@ -6147,7 +6135,7 @@ Optional<Parser::PropertyAndValue> Parser::parse_css_value_for_properties(Readon
 
     if (peek_token.is(Token::Type::String)) {
         if (auto property = any_property_accepts_type(property_ids, ValueType::String); property.has_value())
-            return PropertyAndValue { *property, StringStyleValue::create(MUST(String::from_utf8(tokens.next_token().token().string()))) };
+            return PropertyAndValue { *property, StringStyleValue::create(tokens.next_token().token().string().to_string()) };
     }
 
     if (auto property = any_property_accepts_type(property_ids, ValueType::Url); property.has_value()) {

Userland/Libraries/LibWeb/CSS/Parser/SelectorParsing.cpp

@@ -295,8 +295,8 @@ Parser::ParseErrorOr<Selector::SimpleSelector> Parser::parse_attribute_simple_se
         dbgln_if(CSS_PARSER_DEBUG, "Expected a string or ident for the value to match attribute against, got: '{}'", value_part.to_debug_string());
         return ParseError::SyntaxError;
     }
-    auto value_string_view = value_part.token().is(Token::Type::Ident) ? value_part.token().ident() : value_part.token().string();
-    simple_selector.attribute().value = String::from_utf8(value_string_view).release_value_but_fixme_should_propagate_errors();
+    auto const& value_string = value_part.token().is(Token::Type::Ident) ? value_part.token().ident() : value_part.token().string();
+    simple_selector.attribute().value = value_string.to_string();
 
     attribute_tokens.skip_whitespace();
     // Handle case-sensitivity suffixes. https://www.w3.org/TR/selectors-4/#attribute-case

Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp

@@ -343,7 +343,7 @@ void WindowOrWorkerGlobalScopeMixin::queue_performance_entry(JS::NonnullGCPtr<Pe
         //    or whose type member equals to entryType:
         auto iterator = registered_observer->options_list().find_if([&entry_type](PerformanceTimeline::PerformanceObserverInit const& entry) {
             if (entry.entry_types.has_value())
-                return entry.entry_types->contains_slow(String::from_utf8(entry_type).release_value_but_fixme_should_propagate_errors());
+                return entry.entry_types->contains_slow(entry_type.to_string());
 
             VERIFY(entry.type.has_value());
             return entry.type.value() == entry_type;

Userland/Services/DeviceMapper/DeviceEventLoop.cpp

@@ -131,7 +131,7 @@ ErrorOr<void> DeviceEventLoop::register_new_device(DeviceNodeFamily::Type unix_d
     }
     auto allocated_suffix_index = possible_allocated_suffix_index.release_value();
 
-    auto path = TRY(String::from_utf8(path_pattern));
+    auto path = path_pattern;
     if (match.path_pattern.contains("%digit"sv)) {
         auto replacement = TRY(build_suffix_with_numbers(allocated_suffix_index));
         path = TRY(path.replace("%digit"sv, replacement, ReplaceMode::All));

Userland/Shell/ImmediateFunctions.cpp

@@ -256,7 +256,7 @@ ErrorOr<RefPtr<AST::Node>> Shell::immediate_remove_suffix(AST::ImmediateExpressi
     Vector<NonnullRefPtr<AST::Node>> nodes;
 
     for (auto& value_str : values) {
-        String removed = TRY(String::from_utf8(value_str));
+        String removed = value_str;
 
         if (value_str.bytes_as_string_view().ends_with(suffix_str))
             removed = TRY(removed.substring_from_byte_offset(0, value_str.bytes_as_string_view().length() - suffix_str.bytes_as_string_view().length()));
@@ -288,7 +288,7 @@ ErrorOr<RefPtr<AST::Node>> Shell::immediate_remove_prefix(AST::ImmediateExpressi
     Vector<NonnullRefPtr<AST::Node>> nodes;
 
     for (auto& value_str : values) {
-        String removed = TRY(String::from_utf8(value_str));
+        String removed = value_str;
 
         if (value_str.bytes_as_string_view().starts_with(prefix_str))
             removed = TRY(removed.substring_from_byte_offset(prefix_str.bytes_as_string_view().length()));

Userland/Shell/PosixParser.cpp

@@ -213,7 +213,7 @@ void Parser::handle_heredoc_contents()
 
             return make_ref_counted<AST::StringLiteral>(
                 token.position.value_or(empty_position()),
-                TRY(String::from_utf8(token.value)),
+                token.value,
                 AST::StringLiteral::EnclosureType::None);
         }();
 
@@ -929,7 +929,7 @@ ErrorOr<RefPtr<AST::Node>> Parser::parse_function_definition()
 
     return make_ref_counted<AST::FunctionDeclaration>(
         name.position.value_or(empty_position()).with_end(peek().position.value_or(empty_position())),
-        AST::NameWithPosition { TRY(String::from_utf8(name.value)), name.position.value_or(empty_position()) },
+        AST::NameWithPosition { name.value, name.position.value_or(empty_position()) },
         Vector<AST::NameWithPosition> {},
         body.release_nonnull());
 }
@@ -1603,7 +1603,7 @@ ErrorOr<RefPtr<AST::Node>> Parser::parse_word()
                     token.position.value_or(empty_position()),
                     make_ref_counted<AST::StringLiteral>(
                         token.position.value_or(empty_position()),
-                        TRY(String::from_utf8(x.source_expression)),
+                        x.source_expression,
                         AST::StringLiteral::EnclosureType::DoubleQuotes)),
             },
             Optional<AST::Position> {});