refactor(benchmark): transform code before codegen (#7934)

@overlookmotel suggested this [here](#7926 (comment)).

tasks/benchmark/Cargo.toml

@@ -120,7 +120,15 @@ minifier = [
   "dep:oxc_span",
   "dep:oxc_tasks_common",
 ]
-codegen = ["dep:oxc_allocator", "dep:oxc_codegen", "dep:oxc_parser", "dep:oxc_span", "dep:oxc_tasks_common"]
+codegen = [
+  "dep:oxc_allocator",
+  "dep:oxc_codegen",
+  "dep:oxc_parser",
+  "dep:oxc_semantic",
+  "dep:oxc_span",
+  "dep:oxc_tasks_common",
+  "dep:oxc_transformer",
+]
 linter = [
   "dep:oxc_allocator",
   "dep:oxc_linter",

tasks/benchmark/benches/codegen.rs

@@ -1,28 +1,49 @@
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use oxc_allocator::Allocator;
 use oxc_benchmark::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use oxc_codegen::{CodeGenerator, CodegenOptions};
 use oxc_parser::Parser;
+use oxc_semantic::SemanticBuilder;
 use oxc_span::SourceType;
 use oxc_tasks_common::TestFiles;
+use oxc_transformer::{TransformOptions, Transformer};
 
 fn bench_codegen(criterion: &mut Criterion) {
     for file in TestFiles::complicated_one(0).files() {
         let id = BenchmarkId::from_parameter(&file.file_name);
         let source_type = SourceType::from_path(&file.file_name).unwrap();
         let allocator = Allocator::default();
         let source_text = &file.source_text;
-        let ret = Parser::new(&allocator, source_text, source_type).parse();
+
+        let mut parser_ret = Parser::new(&allocator, source_text, source_type).parse();
+        assert!(parser_ret.errors.is_empty());
 
         let mut group = criterion.benchmark_group("codegen");
-        group.bench_with_input(id.clone(), &ret.program, |b, program| {
+        group.bench_with_input(id.clone(), &parser_ret.program, |b, program| {
             b.iter_with_large_drop(|| CodeGenerator::new().build(program).map);
         });
         group.finish();
 
+        let transformed_program = {
+            let transform_options = TransformOptions::enable_all();
+            let (symbols, scopes) = SemanticBuilder::new()
+                // Estimate transformer will triple scopes, symbols, references
+                .with_excess_capacity(2.0)
+                .build(&parser_ret.program)
+                .semantic
+                .into_symbol_table_and_scope_tree();
+
+            let transformer_ret =
+                Transformer::new(&allocator, Path::new(&file.file_name), &transform_options)
+                    .build_with_symbols_and_scopes(symbols, scopes, &mut parser_ret.program);
+
+            assert!(transformer_ret.errors.is_empty());
+            parser_ret.program
+        };
+
         let mut group = criterion.benchmark_group("codegen_sourcemap");
-        group.bench_with_input(id, &ret.program, |b, program| {
+        group.bench_with_input(id, &transformed_program, |b, program| {
             b.iter_with_large_drop(|| {
                 CodeGenerator::new()
                     .with_options(CodegenOptions {