perf(codegen): remove the useless tokens generated by some expressions

crates/oxc_codegen/src/gen.rs

@@ -188,7 +188,6 @@ impl Gen for Statement<'_> {
 impl Gen for ExpressionStatement<'_> {
     fn r#gen(&self, p: &mut Codegen, _ctx: Context) {
         p.print_comments_at(self.span.start);
-        p.add_source_mapping(self.span);
         p.print_indent();
         p.start_of_stmt = p.code_len();
         p.print_expression(&self.expression);
@@ -1388,7 +1387,7 @@ impl GenExpr for CallExpression<'_> {
         let is_export_default = p.start_of_default_export == p.code_len();
         let mut wrap = precedence >= Precedence::New || ctx.intersects(Context::FORBID_CALL);
         let pure = self.pure && p.options.print_annotation_comment();
-        if precedence >= Precedence::Postfix && pure {
+        if !wrap && pure && precedence >= Precedence::Postfix {
             wrap = true;
         }
 
@@ -1401,7 +1400,6 @@ impl GenExpr for CallExpression<'_> {
             } else if is_statement {
                 p.start_of_stmt = p.code_len();
             }
-            p.add_source_mapping(self.span);
             self.callee.print_expr(p, Precedence::Postfix, Context::empty());
             if self.optional {
                 p.print_str("?.");
@@ -1727,10 +1725,12 @@ impl GenExpr for UnaryExpression<'_> {
             let operator = self.operator.as_str();
             if self.operator.is_keyword() {
                 p.print_space_before_identifier();
+                p.add_source_mapping(self.span);
                 p.print_str(operator);
                 p.print_soft_space();
             } else {
                 p.print_space_before_operator(self.operator.into());
+                p.add_source_mapping(self.span);
                 p.print_str(operator);
                 p.prev_op = Some(self.operator.into());
                 p.prev_op_end = p.code().len();

crates/oxc_codegen/src/sourcemap_builder.rs

@@ -119,7 +119,7 @@ impl<'a> SourcemapBuilder<'a> {
     }
 
     pub fn add_source_mapping(&mut self, output: &[u8], position: u32, name: Option<&str>) {
-        if matches!(self.last_position, Some(last_position) if last_position == position) {
+        if self.last_position == Some(position) {
             return;
         }
         let (original_line, original_column) = self.search_original_line_and_column(position);

crates/oxc_minifier/Cargo.toml

@@ -40,5 +40,6 @@ rustc-hash = { workspace = true }
 [dev-dependencies]
 oxc_parser = { workspace = true }
 
+base64 = { workspace = true }
 insta = { workspace = true }
 pico-args = { workspace = true }

crates/oxc_minifier/examples/minifier.rs

@@ -1,13 +1,15 @@
 #![expect(clippy::print_stdout)]
-use std::path::Path;
+use std::path::{Path, PathBuf};
+
+use base64::{Engine, prelude::BASE64_STANDARD};
+use pico_args::Arguments;
 
 use oxc_allocator::Allocator;
-use oxc_codegen::{Codegen, CodegenOptions, CommentOptions};
+use oxc_codegen::{Codegen, CodegenOptions, CodegenReturn, CommentOptions};
 use oxc_mangler::MangleOptions;
 use oxc_minifier::{CompressOptions, Minifier, MinifierOptions};
 use oxc_parser::Parser;
 use oxc_span::SourceType;
-use pico_args::Arguments;
 
 // Instruction:
 // create a `test.js`,
@@ -19,19 +21,34 @@ fn main() -> std::io::Result<()> {
     let mangle = args.contains("--mangle");
     let nospace = args.contains("--nospace");
     let twice = args.contains("--twice");
+    let sourcemap = args.contains("--sourcemap");
     let name = args.free_from_str().unwrap_or_else(|_| "test.js".to_string());
 
     let path = Path::new(&name);
     let source_text = std::fs::read_to_string(path)?;
     let source_type = SourceType::from_path(path).unwrap();
+    let source_map_path = sourcemap.then(|| path.to_path_buf());
 
     let mut allocator = Allocator::default();
-    let printed = minify(&allocator, &source_text, source_type, mangle, nospace);
+    let ret = minify(&allocator, &source_text, source_type, source_map_path, mangle, nospace);
+    let printed = ret.code;
     println!("{printed}");
 
+    if let Some(source_map) = ret.map {
+        let result = source_map.to_json_string();
+        let hash = BASE64_STANDARD.encode(format!(
+            "{}\0{}{}\0{}",
+            printed.len(),
+            printed,
+            result.len(),
+            result
+        ));
+        println!("https://evanw.github.io/source-map-visualization/#{hash}");
+    }
+
     if twice {
         allocator.reset();
-        let printed2 = minify(&allocator, &printed, source_type, mangle, nospace);
+        let printed2 = minify(&allocator, &printed, source_type, None, mangle, nospace).code;
         println!("{printed2}");
         println!("same = {}", printed == printed2);
     }
@@ -43,9 +60,10 @@ fn minify(
     allocator: &Allocator,
     source_text: &str,
     source_type: SourceType,
+    source_map_path: Option<PathBuf>,
     mangle: bool,
     nospace: bool,
-) -> String {
+) -> CodegenReturn {
     let ret = Parser::new(allocator, source_text, source_type).parse();
     let mut program = ret.program;
     let options = MinifierOptions {
@@ -55,11 +73,11 @@ fn minify(
     let ret = Minifier::new(options).build(allocator, &mut program);
     Codegen::new()
         .with_options(CodegenOptions {
+            source_map_path,
             minify: nospace,
             comments: CommentOptions::disabled(),
             ..CodegenOptions::default()
         })
         .with_scoping(ret.scoping)
         .build(&program)
-        .code
 }

crates/oxc_transformer_plugins/tests/integrations/snapshots/integrations__replace_global_defines__test_sourcemap.snap

@@ -4,17 +4,14 @@ expression: snapshot
 ---
 - test.js.map
 (0:0) "1;\n" --> (0:0) "1;\n"
-(1:0) "__OBJECT__;\n" --> (1:0) "({ 'hello': 'test' });\n"
 (2:0) "2;\n" --> (2:0) "2;\n"
-(3:0) "__STRING__;\n" --> (3:0) "'development';\n"
 (4:0) "3;\n" --> (4:0) "3;\n"
 (5:0) "log(__OBJECT__)" --> (5:0) "log({ 'hello': 'test' })"
 (5:15) ";\n" --> (5:24) ";\n"
 (6:0) "4;\n" --> (6:0) "4;\n"
 (7:0) "log(__STRING__)" --> (7:0) "log('development')"
 (7:15) ";\n" --> (7:18) ";\n"
 (8:0) "5;\n" --> (8:0) "5;\n"
-(9:0) "__OBJECT__." --> (9:0) "({ 'hello': 'test' })."
 (9:11) "hello;\n" --> (9:22) "hello;\n"
 (10:0) "6;\n" --> (10:0) "6;\n"
 (11:0) "log(__MEMBER__)" --> (11:0) "log(xx.yy.zz)"

napi/minify/test/minify.test.ts

@@ -11,7 +11,7 @@ describe('simple', () => {
     expect(ret).toStrictEqual({
       'code': 'function foo(){var e;e(void 0)}foo();',
       'map': {
-        'mappings': 'AACA,SAAS,KAAM,CAAE,IAAIA,EAAK,SAAc,AAAE,CAAC,KAAK',
+        'mappings': 'AACA,SAAS,KAAM,CAAE,IAAIA,EAAKA,EAAI,OAAU,AAAE,CAAC,KAAK',
         'names': [
           'bar',
         ],

napi/transform/test/moduleRunnerTransform.test.ts

@@ -32,7 +32,7 @@ describe('moduleRunnerTransform', () => {
 
     expect(map).toMatchInlineSnapshot(`
       {
-        "mappings": "AAAA;;;;;;;AAAO,MAAM,IAAI",
+        "mappings": ";;;;;;;AAAO,MAAM,IAAI",
         "names": [],
         "sources": [
           "index.js",