feat(codegen): add option for choosing quotes; remove slow choose_quot method (#4219)

crates/oxc_codegen/src/gen.rs

@@ -65,7 +65,7 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for Directive<'a> {
         // A Use Strict Directive may not contain an EscapeSequence or LineContinuation.
         // So here should print original `directive` value, the `expression` value is escaped str.
         // See https://github.com/babel/babel/blob/main/packages/babel-generator/src/generators/base.ts#L64
-        p.wrap_quote(self.directive.as_str(), |p, _| {
+        p.wrap_quote(|p, _| {
             p.print_str(self.directive.as_str());
         });
         p.print_semicolon_after_statement();
@@ -1268,7 +1268,7 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for RegExpLiteral<'a> {
     }
 }
 
-fn print_unquoted_str<const MINIFY: bool>(s: &str, quote: char, p: &mut Codegen<{ MINIFY }>) {
+fn print_unquoted_str<const MINIFY: bool>(s: &str, quote: u8, p: &mut Codegen<{ MINIFY }>) {
     let mut chars = s.chars().peekable();
 
     while let Some(c) = chars.next() {
@@ -1308,21 +1308,21 @@ fn print_unquoted_str<const MINIFY: bool>(s: &str, quote: char, p: &mut Codegen<
                 p.print_str("\\\\");
             }
             '\'' => {
-                if quote == '\'' {
+                if quote == b'\'' {
                     p.print_str("\\'");
                 } else {
                     p.print_str("'");
                 }
             }
             '\"' => {
-                if quote == '"' {
+                if quote == b'"' {
                     p.print_str("\\\"");
                 } else {
                     p.print_str("\"");
                 }
             }
             '`' => {
-                if quote == '`' {
+                if quote == b'`' {
                     p.print_str("\\`");
                 } else {
                     p.print_str("`");
@@ -1354,7 +1354,7 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for StringLiteral<'a> {
     fn gen(&self, p: &mut Codegen<{ MINIFY }>, _ctx: Context) {
         p.add_source_mapping(self.span.start);
         let s = self.value.as_str();
-        p.wrap_quote(s, |p, quote| {
+        p.wrap_quote(|p, quote| {
             print_unquoted_str(s, quote, p);
         });
     }
@@ -2239,7 +2239,7 @@ impl<'a, const MINIFY: bool> Gen<MINIFY> for JSXAttributeValue<'a> {
             Self::Element(el) => el.gen(p, ctx),
             Self::StringLiteral(lit) => {
                 p.print_char(b'"');
-                print_unquoted_str(&lit.value, '"', p);
+                print_unquoted_str(&lit.value, b'"', p);
                 p.print_char(b'"');
             }
             Self::ExpressionContainer(expr_container) => expr_container.gen(p, ctx),

crates/oxc_codegen/src/lib.rs

@@ -39,6 +39,12 @@ pub type CodeGenerator<'a> = Codegen<'a, false>;
 /// Code generator with whitespace removal.
 pub type WhitespaceRemover<'a> = Codegen<'a, true>;
 
+#[derive(Default, Clone, Copy)]
+pub struct CodegenOptions {
+    /// Use single quotes instead of double quotes.
+    pub single_quote: bool,
+}
+
 #[derive(Default, Clone, Copy)]
 pub struct CommentOptions {
     /// Enable preserve annotate comments, like `/* #__PURE__ */` and `/* #__NO_SIDE_EFFECTS__ */`.
@@ -51,6 +57,7 @@ pub struct CodegenReturn {
 }
 
 pub struct Codegen<'a, const MINIFY: bool> {
+    options: CodegenOptions,
     comment_options: CommentOptions,
 
     source_text: &'a str,
@@ -80,6 +87,9 @@ pub struct Codegen<'a, const MINIFY: bool> {
     /// Track the current indentation level
     indent: u32,
 
+    /// Fast path for [CodegenOptions::single_quote]
+    quote: u8,
+
     // Builders
     sourcemap_builder: Option<SourcemapBuilder>,
 
@@ -112,6 +122,7 @@ impl<'a, const MINIFY: bool> Codegen<'a, MINIFY> {
     #[must_use]
     pub fn new() -> Self {
         Self {
+            options: CodegenOptions::default(),
             comment_options: CommentOptions::default(),
             source_text: "",
             trivias: Trivias::default(),
@@ -127,6 +138,7 @@ impl<'a, const MINIFY: bool> Codegen<'a, MINIFY> {
             start_of_arrow_expr: 0,
             start_of_default_export: 0,
             indent: 0,
+            quote: b'"',
             sourcemap_builder: None,
             move_comment_map: MoveCommentMap::default(),
         }
@@ -141,6 +153,13 @@ impl<'a, const MINIFY: bool> Codegen<'a, MINIFY> {
         self
     }
 
+    #[must_use]
+    pub fn with_options(mut self, options: CodegenOptions) -> Self {
+        self.options = options;
+        self.quote = if options.single_quote { b'\'' } else { b'"' };
+        self
+    }
+
     #[must_use]
     pub fn enable_comment(
         mut self,
@@ -467,11 +486,10 @@ impl<'a, const MINIFY: bool> Codegen<'a, MINIFY> {
     }
 
     #[inline]
-    fn wrap_quote<F: FnMut(&mut Self, char)>(&mut self, s: &str, mut f: F) {
-        let quote = Self::choose_quote(s);
-        self.print_char(quote as u8);
-        f(self, quote);
-        self.print_char(quote as u8);
+    fn wrap_quote<F: FnMut(&mut Self, u8)>(&mut self, mut f: F) {
+        self.print_char(self.quote);
+        f(self, self.quote);
+        self.print_char(self.quote);
     }
 
     fn print_directives_and_statements(
@@ -512,24 +530,6 @@ impl<'a, const MINIFY: bool> Codegen<'a, MINIFY> {
             sourcemap_builder.add_source_mapping_for_name(&self.code, span, name);
         }
     }
-
-    fn choose_quote(s: &str) -> char {
-        let mut single_cost = 0;
-        let mut double_cost = 0;
-        for c in s.chars() {
-            match c {
-                '\'' => single_cost += 1,
-                '"' => double_cost += 1,
-                _ => {}
-            }
-        }
-
-        if single_cost > double_cost {
-            '"'
-        } else {
-            '\''
-        }
-    }
 }
 
 pub(crate) type MoveCommentMap = FxHashMap<u32, Comment>;

crates/oxc_codegen/tests/mod.rs

@@ -1,25 +1,29 @@
 use oxc_allocator::Allocator;
-use oxc_codegen::{CodeGenerator, CommentOptions};
+use oxc_codegen::{CodeGenerator, CodegenOptions, CommentOptions};
 use oxc_parser::Parser;
 use oxc_span::SourceType;
 
-fn test(source_text: &str, expected: &str) {
+fn check(source_text: &str, expected: &str, source_type: SourceType) {
     let allocator = Allocator::default();
-    let source_type = SourceType::default().with_module(true);
     let ret = Parser::new(&allocator, source_text, source_type).parse();
-    let result = CodeGenerator::new().build(&ret.program).source_text;
+    let result = CodeGenerator::new()
+        .with_options(CodegenOptions { single_quote: true })
+        .build(&ret.program)
+        .source_text;
     assert_eq!(expected, result, "for source {source_text}, expect {expected}, got {result}");
 }
 
+fn test(source_text: &str, expected: &str) {
+    let source_type = SourceType::default().with_module(true);
+    check(source_text, expected, source_type);
+}
+
 fn test_ts(source_text: &str, expected: &str, is_typescript_definition: bool) {
-    let allocator = Allocator::default();
     let source_type = SourceType::default()
         .with_typescript(true)
         .with_typescript_definition(is_typescript_definition)
         .with_module(true);
-    let ret = Parser::new(&allocator, source_text, source_type).parse();
-    let result = CodeGenerator::new().build(&ret.program).source_text;
-    assert_eq!(expected, result, "for source {source_text}, expect {expected}, got {result}");
+    check(source_text, expected, source_type);
 }
 
 #[test]
@@ -30,7 +34,7 @@ fn string() {
     test("let x = '\t'", "let x = '\t';\n");
     test(r"let x = '\v'", "let x = '\\v';\n");
     test("let x = '\\n'", "let x = '\\n';\n");
-    test("let x = '\\''", "let x = \"'\";\n");
+    test("let x = '\\''", "let x = '\\'';\n");
     test("let x = '\\\"'", "let x = '\"';\n");
     // test( "let x = '\\'''", "let x = `''`;\n");
     test("let x = '\\\\'", "let x = '\\\\';\n");

crates/oxc_isolated_declarations/tests/snapshots/as-const.snap

@@ -5,8 +5,8 @@ input_file: crates/oxc_isolated_declarations/tests/fixtures/as-const.ts
 ==================== .D.TS ====================
 
 declare const F: {
-	readonly string: 'string';
-	readonly templateLiteral: 'templateLiteral';
+	readonly string: "string";
+	readonly templateLiteral: "templateLiteral";
 	readonly number: 1.23;
 	readonly bigint: -1_2_3n;
 	readonly boolean: true;
@@ -15,8 +15,8 @@ declare const F: {
 	readonly function: (a: string) => void;
 	readonly arrow: (a: string) => void;
 	readonly object: {
-		readonly a: 'a';
-		readonly b: 'b';
+		readonly a: "a";
+		readonly b: "b";
 	};
-	readonly array: readonly ['a', undefined, {	readonly b: '\n'}];
+	readonly array: readonly ["a", undefined, {	readonly b: "\n"}];
 };

crates/oxc_isolated_declarations/tests/snapshots/class.snap

@@ -20,7 +20,7 @@ export declare abstract class Qux {
 	baz(): void;
 }
 export declare class Baz {
-	readonly prop1 = 'some string';
+	readonly prop1 = "some string";
 	prop2: string;
 	private prop3;
 	private prop4;

crates/oxc_isolated_declarations/tests/snapshots/eliminate-imports.snap

@@ -4,11 +4,11 @@ input_file: crates/oxc_isolated_declarations/tests/fixtures/eliminate-imports.ts
 ---
 ==================== .D.TS ====================
 
-import { AExtend, BExtend, Type, CImplements1, CImplements2, CType, ThisType1, ThisType2 } from 'mod';
+import { AExtend, BExtend, Type, CImplements1, CImplements2, CType, ThisType1, ThisType2 } from "mod";
 export interface A extends AExtend<Type> {}
 export declare class B extends BExtend<Type> {}
 export declare class C implements CImplements1<CType>, CImplements2<CType> {}
 export declare function foo(this: ThisType1 ): void;
 export declare const bar: (this: ThisType2 ) => void;
-import { type InferType1, type InferType2 } from 'infer';
+import { type InferType1, type InferType2 } from "infer";
 export type F<X extends InferType1> = X extends infer U extends InferType2 ? U : never;

crates/oxc_isolated_declarations/tests/snapshots/infer-template-literal.snap

@@ -4,11 +4,11 @@ input_file: crates/oxc_isolated_declarations/tests/fixtures/infer-template-liter
 ---
 ==================== .D.TS ====================
 
-export declare const CSS_VARS_HELPER = 'useCssVars';
+export declare const CSS_VARS_HELPER = "useCssVars";
 export declare function g(func?: string): void;
 export declare const F: {
-	readonly a: 'a';
-	readonly b: readonly ['b'];
+	readonly a: "a";
+	readonly b: readonly ["b"];
 };
 export declare let GOOD: string;
 export declare const BAD: unknown;

crates/oxc_isolated_declarations/tests/snapshots/mapped-types.snap

@@ -4,8 +4,8 @@ input_file: crates/oxc_isolated_declarations/tests/fixtures/mapped-types.ts
 ---
 ==================== .D.TS ====================
 
-import { K } from 'foo';
-import { T } from 'bar';
+import { K } from "foo";
+import { T } from "bar";
 export interface I {
 	prop: { [key in K] : T};
 }

crates/oxc_linter/src/fixer.rs

@@ -1,6 +1,6 @@
 use std::borrow::Cow;
 
-use oxc_codegen::Codegen;
+use oxc_codegen::{CodeGenerator, CodegenOptions};
 use oxc_diagnostics::OxcDiagnostic;
 use oxc_span::{GetSpan, Span, SPAN};
 
@@ -219,8 +219,8 @@ impl<'c, 'a: 'c> RuleFixer<'c, 'a> {
     }
 
     #[allow(clippy::unused_self)]
-    pub fn codegen(self) -> Codegen<'a, false> {
-        Codegen::<false>::new()
+    pub fn codegen(self) -> CodeGenerator<'a> {
+        CodeGenerator::new().with_options(CodegenOptions { single_quote: true })
     }
 
     #[allow(clippy::unused_self)]

crates/oxc_minifier/tests/mod.rs

@@ -6,7 +6,7 @@ mod oxc;
 // mod terser;
 
 use oxc_allocator::Allocator;
-use oxc_codegen::WhitespaceRemover;
+use oxc_codegen::{CodegenOptions, WhitespaceRemover};
 use oxc_minifier::{CompressOptions, Minifier, MinifierOptions};
 use oxc_parser::Parser;
 use oxc_span::SourceType;
@@ -20,7 +20,10 @@ pub(crate) fn minify(
     let ret = Parser::new(&allocator, source_text, source_type).parse();
     let program = allocator.alloc(ret.program);
     Minifier::new(options).build(&allocator, program);
-    WhitespaceRemover::new().build(program).source_text
+    WhitespaceRemover::new()
+        .with_options(CodegenOptions { single_quote: true })
+        .build(program)
+        .source_text
 }
 
 pub(crate) fn test(source_text: &str, expected: &str) {

crates/oxc_minifier/tests/oxc/remove_dead_code.rs

@@ -1,5 +1,5 @@
 use oxc_allocator::Allocator;
-use oxc_codegen::CodeGenerator;
+use oxc_codegen::{CodeGenerator, CodegenOptions};
 use oxc_minifier::RemoveDeadCode;
 use oxc_parser::Parser;
 use oxc_span::SourceType;
@@ -12,7 +12,10 @@ fn print(source_text: &str, remove_dead_code: bool) -> String {
     if remove_dead_code {
         RemoveDeadCode::new(&allocator).build(program);
     }
-    CodeGenerator::new().build(program).source_text
+    CodeGenerator::new()
+        .with_options(CodegenOptions { single_quote: true })
+        .build(program)
+        .source_text
 }
 
 pub(crate) fn test(source_text: &str, expected: &str) {

crates/oxc_minifier/tests/oxc/replace_global_defines.rs

@@ -1,5 +1,5 @@
 use oxc_allocator::Allocator;
-use oxc_codegen::WhitespaceRemover;
+use oxc_codegen::{CodegenOptions, WhitespaceRemover};
 use oxc_minifier::{ReplaceGlobalDefines, ReplaceGlobalDefinesConfig};
 use oxc_parser::Parser;
 use oxc_span::SourceType;
@@ -11,7 +11,10 @@ pub(crate) fn test(source_text: &str, expected: &str, config: ReplaceGlobalDefin
         let ret = Parser::new(&allocator, source_text, source_type).parse();
         let program = allocator.alloc(ret.program);
         ReplaceGlobalDefines::new(&allocator, config).build(program);
-        WhitespaceRemover::new().build(program).source_text
+        WhitespaceRemover::new()
+            .with_options(CodegenOptions { single_quote: true })
+            .build(program)
+            .source_text
     };
     assert_eq!(minified, expected, "for source {source_text}");
 }

tasks/coverage/transpile.snap

@@ -22,9 +22,9 @@ export type A = {
 	[(globalThis.Symbol).unscopables]: number;
 	[aliasing.isConcatSpreadable]: number;
 	[1]: number;
-	['2']: number;
+	["2"]: number;
 	[(missing2)]: number;
-	[Math.random() > 0.5 ? 'f1' : 'f2']: number;
+	[Math.random() > 0.5 ? "f1" : "f2"]: number;
 };
 export interface B {
 	[missing]: number;
@@ -35,9 +35,9 @@ export interface B {
 	[(globalThis.Symbol).unscopables]: number;
 	[aliasing.isConcatSpreadable]: number;
 	[1]: number;
-	['2']: number;
+	["2"]: number;
 	[(missing2)]: number;
-	[Math.random() > 0.5 ? 'f1' : 'f2']: number;
+	[Math.random() > 0.5 ? "f1" : "f2"]: number;
 }
 export class C {
 	[missing]: number = 1;
@@ -48,9 +48,9 @@ export class C {
 	[(globalThis.Symbol).unscopables]: number = 1;
 	[aliasing.isConcatSpreadable]: number = 1;
 	[1]: number = 1;
-	['2']: number = 1;
+	["2"]: number = 1;
 	[(missing2)]: number = 1;
-	[Math.random() > 0.5 ? 'f1' : 'f2']: number = 1;
+	[Math.random() > 0.5 ? "f1" : "f2"]: number = 1;
 }
 export const D = {
 	[missing]: 1,
@@ -61,9 +61,9 @@ export const D = {
 	[(globalThis.Symbol).unscopables]: 1,
 	[aliasing.isConcatSpreadable]: 1,
 	[1]: 1,
-	['2']: 1,
+	["2"]: 1,
 	[(missing2)]: 1,
-	[Math.random() > 0.5 ? 'f1' : 'f2']: 1
+	[Math.random() > 0.5 ? "f1" : "f2"]: 1
 };
 
 //// [declarationComputedPropertyNames.d.ts] ////
@@ -80,9 +80,9 @@ export type A = {
 	[(globalThis.Symbol).unscopables]: number;
 	[aliasing.isConcatSpreadable]: number;
 	[1]: number;
-	['2']: number;
+	["2"]: number;
 	[(missing2)]: number;
-	[Math.random() > 0.5 ? 'f1' : 'f2']: number;
+	[Math.random() > 0.5 ? "f1" : "f2"]: number;
 };
 export interface B {
 	[missing]: number;
@@ -93,17 +93,17 @@ export interface B {
 	[(globalThis.Symbol).unscopables]: number;
 	[aliasing.isConcatSpreadable]: number;
 	[1]: number;
-	['2']: number;
+	["2"]: number;
 	[(missing2)]: number;
-	[Math.random() > 0.5 ? 'f1' : 'f2']: number;
+	[Math.random() > 0.5 ? "f1" : "f2"]: number;
 }
 export declare class C {
 	[1]: number;
-	['2']: number;
+	["2"]: number;
 }
 export declare const D: {
 	1: number;
-	'2': number;
+	"2": number;
 };
 export {};
   x TS9010: Variable must have an explicit type annotation with