feat(next-swc): Add CJS optimizer again (#50249)

### What?

This reverts commit 6ebc725 / #50247.

### Why?

#49972 is reverted due to bugs, and I'm retrying it.

### How?

Closes WEB-1072
Closes WEB-1097
Closes NEXT-1156 (as it's reopened by the revert PR)

fix #48469

---------

Co-authored-by: Shu Ding <[email protected]>

packages/next-swc/crates/core/Cargo.toml

@@ -9,6 +9,7 @@ plugin = ["turbopack-binding/__swc_core_binding_napi_plugin"]
 
 [dependencies]
 chrono = "0.4"
+convert_case = "0.5.0"
 easy-error = "1.0.0"
 either = "1"
 fxhash = "0.2.1"
@@ -17,6 +18,7 @@ once_cell = { workspace = true }
 next-transform-font = {workspace = true}
 pathdiff = "0.2.0"
 regex = "1.5"
+rustc-hash = "1"
 serde = "1"
 serde_json = "1"
 sha1 = "0.10.1"

packages/next-swc/crates/core/src/cjs_optimizer.rs

@@ -0,0 +1,279 @@
+use rustc_hash::{FxHashMap, FxHashSet};
+use serde::Deserialize;
+use turbopack_binding::swc::core::{
+ common::{util::take::Take, SyntaxContext, DUMMY_SP},
+ ecma::{
+ ast::{
+ CallExpr, Callee, Decl, Expr, Id, Ident, Lit, MemberExpr, MemberProp, Module,
+ ModuleItem, Pat, Script, Stmt, VarDecl, VarDeclKind, VarDeclarator,
+ },
+ atoms::{Atom, JsWord},
+ utils::{prepend_stmts, private_ident, ExprFactory, IdentRenamer},
+ visit::{
+ as_folder, noop_visit_mut_type, noop_visit_type, Fold, Visit, VisitMut, VisitMutWith,
+ VisitWith,
+ },
+ },
+};
+
+pub fn cjs_optimizer(config: Config, unresolved_ctxt: SyntaxContext) -> impl Fold + VisitMut {
+ as_folder(CjsOptimizer {
+ data: State::default(),
+ packages: config.packages,
+ unresolved_ctxt,
+ })
+}
+
+#[derive(Clone, Debug, Deserialize)]
+pub struct Config {
+ pub packages: FxHashMap<String, PackageConfig>,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct PackageConfig {
+ pub transforms: FxHashMap<JsWord, JsWord>,
+}
+
+struct CjsOptimizer {
+ data: State,
+ packages: FxHashMap<String, PackageConfig>,
+ unresolved_ctxt: SyntaxContext,
+}
+
+#[derive(Debug, Default)]
+struct State {
+ /// List of `require` calls **which should be replaced**.
+ ///
+ /// `(identifier): (module_record)`
+ imports: FxHashMap<Id, ImportRecord>,
+
+ /// `(module_specifier, property): (identifier)`
+ replaced: FxHashMap<(Atom, JsWord), Id>,
+
+ extra_stmts: Vec<Stmt>,
+
+ rename_map: FxHashMap<Id, Id>,
+
+ /// Ignored identifiers for `obj` of [MemberExpr].
+ ignored: FxHashSet<Id>,
+
+ is_prepass: bool,
+}
+
+#[derive(Debug)]
+struct ImportRecord {
+ module_specifier: Atom,
+}
+
+impl CjsOptimizer {
+ fn should_rewrite(&self, module_specifier: &str) -> Option<&FxHashMap<JsWord, JsWord>> {
+ self.packages.get(module_specifier).map(|v| &v.transforms)
+ }
+}
+
+impl VisitMut for CjsOptimizer {
+ noop_visit_mut_type!();
+
+ fn visit_mut_module_items(&mut self, stmts: &mut Vec<ModuleItem>) {
+ self.data.is_prepass = true;
+ stmts.visit_mut_children_with(self);
+ self.data.is_prepass = false;
+ stmts.visit_mut_children_with(self);
+ }
+
+ fn visit_mut_expr(&mut self, e: &mut Expr) {
+ e.visit_mut_children_with(self);
+
+ if let Expr::Member(n) = e {
+ if let MemberProp::Ident(prop) = &n.prop {
+ if let Expr::Ident(obj) = &*n.obj {
+ let key = obj.to_id();
+ if self.data.ignored.contains(&key) {
+ return;
+ }
+
+ if let Some(record) = self.data.imports.get(&key) {
+ let mut replaced = false;
+
+ let new_id = self
+ .data
+ .replaced
+ .entry((record.module_specifier.clone(), prop.sym.clone()))
+ .or_insert_with(|| private_ident!(prop.sym.clone()).to_id())
+ .clone();
+
+ if let Some(map) = self.should_rewrite(&record.module_specifier) {
+ if let Some(renamed) = map.get(&prop.sym) {
+ replaced = true;
+ if !self.data.is_prepass {
+ // Transform as `require('foo').bar`
+ let var = VarDeclarator {
+ span: DUMMY_SP,
+ name: Pat::Ident(new_id.clone().into()),
+ init: Some(Box::new(Expr::Member(MemberExpr {
+ span: DUMMY_SP,
+ obj: Box::new(Expr::Call(CallExpr {
+ span: DUMMY_SP,
+ callee: Ident::new(
+ "require".into(),
+ DUMMY_SP.with_ctxt(self.unresolved_ctxt),
+ )
+ .as_callee(),
+ args: vec![Expr::Lit(Lit::Str(
+ renamed.clone().into(),
+ ))
+ .as_arg()],
+ type_args: None,
+ })),
+ prop: MemberProp::Ident(Ident::new(
+ prop.sym.clone(),
+ DUMMY_SP.with_ctxt(self.unresolved_ctxt),
+ )),
+ }))),
+ definite: false,
+ };
+
+ self.data.extra_stmts.push(Stmt::Decl(Decl::Var(Box::new(
+ VarDecl {
+ span: DUMMY_SP,
+ kind: VarDeclKind::Const,
+ declare: false,
+ decls: vec![var],
+ },
+ ))));
+
+ *e = Expr::Ident(new_id.into());
+ }
+ }
+ }
+
+ if !replaced {
+ self.data.ignored.insert(key);
+ }
+ }
+ }
+ }
+ }
+ }
+
+ fn visit_mut_module(&mut self, n: &mut Module) {
+ n.visit_children_with(&mut Analyzer {
+ data: &mut self.data,
+ in_member_or_var: false,
+ });
+
+ n.visit_mut_children_with(self);
+
+ prepend_stmts(
+ &mut n.body,
+ self.data.extra_stmts.drain(..).map(ModuleItem::Stmt),
+ );
+
+ n.visit_mut_children_with(&mut IdentRenamer::new(&self.data.rename_map));
+ }
+
+ fn visit_mut_script(&mut self, n: &mut Script) {
+ n.visit_children_with(&mut Analyzer {
+ data: &mut self.data,
+ in_member_or_var: false,
+ });
+
+ n.visit_mut_children_with(self);
+
+ prepend_stmts(&mut n.body, self.data.extra_stmts.drain(..));
+
+ n.visit_mut_children_with(&mut IdentRenamer::new(&self.data.rename_map));
+ }
+
+ fn visit_mut_stmt(&mut self, n: &mut Stmt) {
+ n.visit_mut_children_with(self);
+
+ if let Stmt::Decl(Decl::Var(v)) = n {
+ if v.decls.is_empty() {
+ n.take();
+ }
+ }
+ }
+
+ fn visit_mut_var_declarator(&mut self, n: &mut VarDeclarator) {
+ n.visit_mut_children_with(self);
+
+ // Find `require('foo')`
+ if let Some(Expr::Call(CallExpr {
+ callee: Callee::Expr(callee),
+ args,
+ ..
+ })) = n.init.as_deref()
+ {
+ if let Expr::Ident(ident) = &**callee {
+ if ident.span.ctxt == self.unresolved_ctxt && ident.sym == *"require" {
+ if let Some(arg) = args.get(0) {
+ if let Expr::Lit(Lit::Str(v)) = &*arg.expr {
+ // TODO: Config
+
+ if let Pat::Ident(name) = &n.name {
+ if let Some(..) = self.should_rewrite(&v.value) {
+ let key = name.to_id();
+
+ if !self.data.is_prepass {
+ if !self.data.ignored.contains(&key) {
+ // Drop variable declarator.
+ n.name.take();
+ }
+ } else {
+ self.data.imports.insert(
+ key,
+ ImportRecord {
+ module_specifier: v.value.clone().into(),
+ },
+ );
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+ fn visit_mut_var_declarators(&mut self, n: &mut Vec<VarDeclarator>) {
+ n.visit_mut_children_with(self);
+
+ // We make `name` invalid if we should drop it.
+ n.retain(|v| !v.name.is_invalid());
+ }
+}
+
+struct Analyzer<'a> {
+ in_member_or_var: bool,
+ data: &'a mut State,
+}
+
+impl Visit for Analyzer<'_> {
+ noop_visit_type!();
+
+ fn visit_var_declarator(&mut self, n: &VarDeclarator) {
+ self.in_member_or_var = true;
+ n.visit_children_with(self);
+ self.in_member_or_var = false;
+ }
+
+ fn visit_member_expr(&mut self, e: &MemberExpr) {
+ self.in_member_or_var = true;
+ e.visit_children_with(self);
+ self.in_member_or_var = false;
+
+ if let (Expr::Ident(obj), MemberProp::Computed(..)) = (&*e.obj, &e.prop) {
+ self.data.ignored.insert(obj.to_id());
+ }
+ }
+
+ fn visit_ident(&mut self, i: &Ident) {
+ i.visit_children_with(self);
+ if !self.in_member_or_var {
+ self.data.ignored.insert(i.to_id());
+ }
+ }
+}

packages/next-swc/crates/core/src/lib.rs

@@ -38,14 +38,18 @@ use fxhash::FxHashSet;
 use next_transform_font::next_font_loaders;
 use serde::Deserialize;
 use turbopack_binding::swc::core::{
- common::{chain, comments::Comments, pass::Optional, FileName, SourceFile, SourceMap},
+ common::{
+ chain, comments::Comments, pass::Optional, FileName, Mark, SourceFile, SourceMap,
+ SyntaxContext,
+ },
  ecma::{
  ast::EsVersion, parser::parse_file_as_module, transforms::base::pass::noop, visit::Fold,
  },
 };
 
 pub mod amp_attributes;
 mod auto_cjs;
+pub mod cjs_optimizer;
 pub mod disallow_re_export_all_in_page;
 pub mod next_dynamic;
 pub mod next_ssg;
@@ -125,6 +129,9 @@ pub struct TransformOptions {
 
  #[serde(default)]
  pub server_actions: Option<server_actions::Config>,
+
+ #[serde(default)]
+ pub cjs_require_optimizer: Option<cjs_optimizer::Config>,
 }
 
 pub fn custom_before_pass<'a, C: Comments + 'a>(
@@ -133,6 +140,7 @@ pub fn custom_before_pass<'a, C: Comments + 'a>(
  opts: &'a TransformOptions,
  comments: C,
  eliminated_packages: Rc<RefCell<FxHashSet<String>>>,
+ unresolved_mark: Mark,
 ) -> impl Fold + 'a
 where
  C: Clone,
@@ -277,6 +285,12 @@ where
  )),
  None => Either::Right(noop()),
  },
+ match &opts.cjs_require_optimizer {
+ Some(config) => {
+ Either::Left(cjs_optimizer::cjs_optimizer(config.clone(), SyntaxContext::empty().apply_mark(unresolved_mark)))
+ },
+ None => Either::Right(noop()),
+ },
  )
 }