refactor(linter): use cow_to_ascii_lowercase instead cow_to_lowercase (#8678)

`cow_to_lowercase` is slow as it deals with unicode.

closes #8659

crates/oxc_codegen/src/gen.rs

@@ -1346,7 +1346,7 @@ impl Gen for RegExpLiteral<'_> {
         let pattern_text = self.regex.pattern.source_text(p.source_text);
         // Avoid forming a single-line comment or "</script" sequence
         if last == Some(b'/')
-            || (last == Some(b'<') && pattern_text.cow_to_lowercase().starts_with("script"))
+            || (last == Some(b'<') && pattern_text.cow_to_ascii_lowercase().starts_with("script"))
         {
             p.print_hard_space();
         }

crates/oxc_linter/src/rules/eslint/no_loss_of_precision.rs

@@ -186,7 +186,7 @@ impl<'a> RawNum<'a> {
 impl NoLossOfPrecision {
     fn not_base_ten_loses_precision(node: &'_ NumericLiteral) -> bool {
         let raw = node.raw.as_ref().unwrap().as_str().cow_replace('_', "");
-        let raw = raw.cow_to_uppercase();
+        let raw = raw.cow_to_ascii_uppercase();
         #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
         // AST always store number as f64, need a cast to format in bin/oct/hex
         let value = node.value as u64;
@@ -197,7 +197,7 @@ impl NoLossOfPrecision {
         } else {
             format!("{value:o}")
         };
-        !raw.ends_with(&suffix.cow_to_uppercase().as_ref())
+        !raw.ends_with(&suffix.cow_to_ascii_uppercase().as_ref())
     }
 
     fn base_ten_loses_precision(node: &'_ NumericLiteral) -> bool {

crates/oxc_linter/src/rules/eslint/no_script_url.rs

@@ -44,7 +44,7 @@ impl Rule for NoScriptUrl {
     fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
         match node.kind() {
             AstKind::StringLiteral(literal)
-                if literal.value.cow_to_lowercase().starts_with("javascript:") =>
+                if literal.value.cow_to_ascii_lowercase().starts_with("javascript:") =>
             {
                 emit_diagnostic(ctx, literal.span);
             }
@@ -58,7 +58,7 @@ impl Rule for NoScriptUrl {
                         .unwrap()
                         .value
                         .raw
-                        .cow_to_lowercase()
+                        .cow_to_ascii_lowercase()
                         .starts_with("javascript:")
                 {
                     emit_diagnostic(ctx, literal.span);

crates/oxc_linter/src/rules/eslint/no_unused_vars/diagnostic.rs

@@ -54,7 +54,7 @@ where
         .with_label(symbol.span().label(format!("'{name}' is declared here")))
         .with_help(format!(
             "Consider renaming this {}{help_suffix}",
-            pronoun_singular.cow_to_lowercase()
+            pronoun_singular.cow_to_ascii_lowercase()
         ))
 }
 /// Variable 'x' is declared but never used.

crates/oxc_linter/src/rules/eslint/sort_imports.rs

@@ -213,9 +213,9 @@ impl SortImports {
 
         if self.ignore_case {
             current_local_member_name = current_local_member_name
-                .map(|name| Cow::Owned(name.cow_to_lowercase().into_owned()));
+                .map(|name| Cow::Owned(name.cow_to_ascii_lowercase().into_owned()));
             previous_local_member_name = previous_local_member_name
-                .map(|name| Cow::Owned(name.cow_to_lowercase().into_owned()));
+                .map(|name| Cow::Owned(name.cow_to_ascii_lowercase().into_owned()));
         }
 
         // "memberSyntaxSortOrder": ["none", "all", "multiple", "single"]
@@ -285,7 +285,7 @@ impl SortImports {
                 let b = window[1].local.name.as_str();
 
                 if self.ignore_case {
-                    a.cow_to_lowercase() > b.cow_to_lowercase()
+                    a.cow_to_ascii_lowercase() > b.cow_to_ascii_lowercase()
                 } else {
                     a > b
                 }
@@ -332,7 +332,7 @@ impl SortImports {
                         let b = b.local.name.as_str();
 
                         if self.ignore_case {
-                            a.cow_to_lowercase().cmp(&b.cow_to_lowercase())
+                            a.cow_to_ascii_lowercase().cmp(&b.cow_to_ascii_lowercase())
                         } else {
                             a.cmp(b)
                         }

crates/oxc_linter/src/rules/eslint/sort_keys.rs

@@ -169,7 +169,7 @@ impl Rule for SortKeys {
                 for group in &mut property_groups {
                     *group = group
                         .iter()
-                        .map(|s| s.cow_to_lowercase().to_string())
+                        .map(|s| s.cow_to_ascii_lowercase().to_string())
                         .collect::<Vec<String>>();
                 }
             }

crates/oxc_linter/src/rules/eslint/sort_vars.rs

@@ -95,7 +95,7 @@ impl SortVars {
         };
 
         if self.ignore_case {
-            return ident.name.as_str().cow_to_lowercase();
+            return ident.name.as_str().cow_to_ascii_lowercase();
         }
 
         Cow::Borrowed(ident.name.as_str()) // avoid string allocs in the default case

crates/oxc_linter/src/rules/jsx_a11y/aria_props.rs

@@ -55,7 +55,7 @@ impl Rule for AriaProps {
     fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
         if let AstKind::JSXAttributeItem(JSXAttributeItem::Attribute(attr)) = node.kind() {
             let name = get_jsx_attribute_name(&attr.name);
-            let name = name.cow_to_lowercase();
+            let name = name.cow_to_ascii_lowercase();
             if name.starts_with("aria-") && !VALID_ARIA_PROPS.contains(&name) {
                 let suggestion = COMMON_TYPOS.get(&name).copied();
                 let diagnostic = aria_props_diagnostic(attr.span, &name, suggestion);

crates/oxc_linter/src/rules/jsx_a11y/aria_unsupported_elements.rs

@@ -58,7 +58,7 @@ impl Rule for AriaUnsupportedElements {
                         JSXAttributeItem::SpreadAttribute(_) => continue,
                     };
                     let attr_name = get_jsx_attribute_name(&attr.name);
-                    let attr_name = attr_name.cow_to_lowercase();
+                    let attr_name = attr_name.cow_to_ascii_lowercase();
                     if INVALID_ATTRIBUTES.contains(&attr_name) {
                         ctx.diagnostic_with_fix(
                             aria_unsupported_elements_diagnostic(attr.span, &attr_name),

crates/oxc_linter/src/rules/jsx_a11y/role_supports_aria_props.rs

@@ -86,7 +86,7 @@ impl Rule for RoleSupportsAriaProps {
             for attr in &jsx_el.attributes {
                 if let JSXAttributeItem::Attribute(attr) = attr {
                     let name = get_jsx_attribute_name(&attr.name);
-                    let name = name.cow_to_lowercase();
+                    let name = name.cow_to_ascii_lowercase();
                     if invalid_props.contains(&&name.as_ref()) {
                         ctx.diagnostic(if is_implicit {
                             is_implicit_diagnostic(attr.span, &name, role_value, &el_type)

crates/oxc_linter/src/rules/react/jsx_key.rs

@@ -101,7 +101,7 @@ pub fn import_matcher<'a>(
     actual_local_name: &'a str,
     expected_module_name: &'a str,
 ) -> bool {
-    let expected_module_name = expected_module_name.cow_to_lowercase();
+    let expected_module_name = expected_module_name.cow_to_ascii_lowercase();
     ctx.module_record().import_entries.iter().any(|import| {
         import.module_request.name() == expected_module_name
             && import.local_name.name() == actual_local_name

crates/oxc_linter/src/rules/react/no_unknown_property.rs

@@ -427,9 +427,10 @@ const DOM_PROPERTIES_IGNORE_CASE: [&str; 5] = [
 ];
 
 lazy_static! {
-    static ref DOM_PROPERTIES_LOWER_MAP: FxHashMap<String, &'static str> = DOM_PROPERTIES_NAMES
+    static ref DOM_PROPERTIES_LOWER_MAP: FxHashMap<Cow<'static, str>, &'static str> =
+        DOM_PROPERTIES_NAMES
             .iter()
-        .map(|it| (it.cow_to_lowercase().into_owned(), *it))
+            .map(|it| (it.cow_to_ascii_lowercase(), *it))
             .collect::<FxHashMap<_, _>>();
 }
 
@@ -442,7 +443,7 @@ fn is_valid_data_attr(name: &str) -> bool {
         return false;
     }
 
-    if name.cow_to_lowercase().starts_with("data-xml") {
+    if name.cow_to_ascii_lowercase().starts_with("data-xml") {
         return false;
     }
 
@@ -519,7 +520,7 @@ impl Rule for NoUnknownProperty {
                     if self.0.require_data_lowercase && has_uppercase(&actual_name) {
                         ctx.diagnostic(data_lowercase_required(
                             span,
-                            &actual_name.cow_to_lowercase(),
+                            &actual_name.cow_to_ascii_lowercase(),
                         ));
                     }
                     return;
@@ -544,7 +545,7 @@ impl Rule for NoUnknownProperty {
                 }
 
                 DOM_PROPERTIES_LOWER_MAP
-                    .get(&name.cow_to_lowercase().into_owned())
+                    .get(&name.cow_to_ascii_lowercase())
                     .or_else(|| DOM_ATTRIBUTES_TO_CAMEL.get(name))
                     .map_or_else(
                         || {

crates/oxc_linter/src/rules/typescript/ban_types.rs

@@ -71,7 +71,7 @@ impl Rule for BanTypes {
                     "String" | "Boolean" | "Number" | "Symbol" | "BigInt" => {
                         ctx.diagnostic(type_diagnostic(
                             name.as_str(),
-                            &name.as_str().cow_to_lowercase(),
+                            &name.as_str().cow_to_ascii_lowercase(),
                             typ.span,
                         ));
                     }

crates/oxc_linter/src/rules/typescript/no_wrapper_object_types.rs

@@ -93,7 +93,7 @@ impl Rule for NoWrapperObjectTypes {
 
             if can_fix {
                 ctx.diagnostic_with_fix(no_wrapper_object_types(ident_span), |fixer| {
-                    fixer.replace(ident_span, ident_name.cow_to_lowercase())
+                    fixer.replace(ident_span, ident_name.cow_to_ascii_lowercase())
                 });
             } else {
                 ctx.diagnostic(no_wrapper_object_types(ident_span));

crates/oxc_linter/src/rules/unicorn/number_literal_case.rs

@@ -103,7 +103,7 @@ fn check_number_literal(number_literal: &str, raw_span: Span) -> Option<(OxcDiag
                 Span::new(raw_span.start + 1, raw_span.start + 2),
                 if number_literal.starts_with("0B") { "0b" } else { "0o" },
             ),
-            number_literal.cow_to_lowercase().into_owned(),
+            number_literal.cow_to_ascii_lowercase().into_owned(),
         ));
     }
     if number_literal.starts_with("0X") || number_literal.starts_with("0x") {
@@ -133,14 +133,14 @@ fn check_number_literal(number_literal: &str, raw_span: Span) -> Option<(OxcDiag
         let char_position = raw_span.start + index as u32;
         return Some((
             uppercase_exponential_notation(Span::new(char_position, char_position + 1)),
-            number_literal.cow_to_lowercase().into_owned(),
+            number_literal.cow_to_ascii_lowercase().into_owned(),
         ));
     }
     None
 }
 
 fn digits_to_uppercase(digits: &str) -> String {
-    let mut result = digits.cow_to_uppercase().into_owned();
+    let mut result = digits.cow_to_ascii_uppercase().into_owned();
     if result.ends_with('N') {
         result.truncate(result.len() - 1);
         result.push('n');

crates/oxc_syntax/src/es_target.rs

@@ -27,7 +27,7 @@ impl FromStr for ESTarget {
     type Err = String;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match s.cow_to_lowercase().as_ref() {
+        match s.cow_to_ascii_lowercase().as_ref() {
             "es5" => Ok(Self::ES5),
             "es6" | "es2015" => Ok(Self::ES2015),
             "es2016" => Ok(Self::ES2016),