fix(es/decorator): Add support for private access expressions in lega…

…cy decorators (#9535)

**Related issue:**

- Closes #9429

.changeset/nasty-ligers-reflect.md

@@ -0,0 +1,6 @@
+---
+swc_ecma_transforms_proposal: patch
+swc_core: patch
+---
+
+fix(es/decorator): Add support for private access expressions in legacy decorators

crates/swc/tests/fixture/issues-9xxx/9429/input/.swcrc

@@ -0,0 +1,20 @@
+{
+ "jsc": {
+ "parser": {
+ "syntax": "typescript",
+ "tsx": true,
+ "decorators": true
+ },
+ "target": "es2022",
+ "loose": false,
+ "minify": {
+ "compress": false,
+ "mangle": false
+ }
+ },
+ "module": {
+ "type": "es6"
+ },
+ "minify": false,
+ "isModule": true
+}

crates/swc/tests/fixture/issues-9xxx/9429/input/index.ts

@@ -0,0 +1,25 @@
+class Foo {
+ static #loggedMethod<Args extends unknown[], Ret>(
+ _prototype: typeof Foo.prototype,
+ _propertyKey: string,
+ descriptor: TypedPropertyDescriptor<(this: Foo, ...args: Args) => Promise<Ret>>,
+ ) {
+ const method = descriptor.value!;
+ descriptor.value = function (...args) {
+ try {
+ console.log("before");
+ return method.apply(this, args);
+ } finally {
+ console.log("after");
+ }
+ };
+ }
+
+ @(Foo.#loggedMethod)
+ public greet(): any {
+ console.log("hi");
+ }
+}
+
+const foo = new Foo();
+foo.greet();

crates/swc/tests/fixture/issues-9xxx/9429/input/test.ts

@@ -0,0 +1,24 @@
+class Foo {
+ static {
+ class Bar {
+ static #x() {}
+
+ @Bar.#x
+ foo() {}
+ }
+ }
+
+ static #y() {}
+
+ @Foo.#y
+ public foo() {}
+
+ static {
+ class Bar {
+ static #x() {}
+
+ @Bar.#x
+ foo() {}
+ }
+ }
+}

crates/swc/tests/fixture/issues-9xxx/9429/output/index.ts

@@ -0,0 +1,24 @@
+var _ts_decorate = require("@swc/helpers/_/_ts_decorate");
+class Foo {
+ static #loggedMethod(_prototype, _propertyKey, descriptor) {
+ const method = descriptor.value;
+ descriptor.value = function(...args) {
+ try {
+ console.log("before");
+ return method.apply(this, args);
+ } finally{
+ console.log("after");
+ }
+ };
+ }
+ greet() {
+ console.log("hi");
+ }
+ static{
+ _ts_decorate._([
+ Foo.#loggedMethod
+ ], Foo.prototype, "greet", null);
+ }
+}
+const foo = new Foo();
+foo.greet();

crates/swc/tests/fixture/issues-9xxx/9429/output/test.ts

@@ -0,0 +1,32 @@
+var _ts_decorate = require("@swc/helpers/_/_ts_decorate");
+class Foo {
+ static{
+ class Bar {
+ static #x() {}
+ foo() {}
+ static{
+ _ts_decorate._([
+ Bar.#x
+ ], Bar.prototype, "foo", null);
+ }
+ }
+ }
+ static #y() {}
+ foo() {}
+ static{
+ class Bar {
+ static #x() {}
+ foo() {}
+ static{
+ _ts_decorate._([
+ Bar.#x
+ ], Bar.prototype, "foo", null);
+ }
+ }
+ }
+ static{
+ _ts_decorate._([
+ Foo.#y
+ ], Foo.prototype, "foo", null);
+ }
+}

crates/swc_ecma_transforms_proposal/src/decorators/legacy/mod.rs

@@ -26,6 +26,7 @@ pub(super) fn new(metadata: bool) -> TscDecorator {
  enums: Default::default(),
  vars: Default::default(),
  appended_exprs: Default::default(),
+ appended_private_access_exprs: Default::default(),
  prepended_exprs: Default::default(),
  class_name: Default::default(),
 
@@ -41,6 +42,7 @@ pub(super) struct TscDecorator {
  /// Used for computed keys, and this variables are not initialized.
  vars: Vec<VarDeclarator>,
  appended_exprs: Vec<Box<Expr>>,
+ appended_private_access_exprs: Vec<Box<Expr>>,
  prepended_exprs: Vec<Box<Expr>>,
 
  class_name: Option<Ident>,
@@ -155,6 +157,17 @@ impl TscDecorator {
  prop_name_to_expr_value(k.clone())
  }
 
+ fn has_private_access(mut expr: &Expr) -> bool {
+ while let Some(MemberExpr { obj, prop, .. }) = expr.as_member() {
+ if prop.is_private_name() {
+ return true;
+ }
+ expr = obj;
+ }
+
+ false
+ }
+
  /// Creates `__decorate` calls.
  fn add_decorate_call(
  &mut self,
@@ -163,10 +176,17 @@ impl TscDecorator {
  key: ExprOrSpread,
  mut desc: ExprOrSpread,
  ) {
+ let mut has_private_access = false;
  let decorators = ArrayLit {
  span: DUMMY_SP,
  elems: decorators
  .into_iter()
+ .inspect(|e| {
+ if has_private_access {
+ return;
+ }
+ has_private_access = Self::has_private_access(e);
+ })
  .map(|mut v| {
  remove_span(&mut v);
 
@@ -180,15 +200,18 @@ impl TscDecorator {
  remove_span(&mut target.expr);
  remove_span(&mut desc.expr);
 
- self.appended_exprs.push(
- CallExpr {
- span: DUMMY_SP,
- callee: helper!(ts, ts_decorate),
- args: vec![decorators, target, key, desc],
- ..Default::default()
- }
- .into(),
- );
+ let expr = CallExpr {
+ callee: helper!(ts, ts_decorate),
+ args: vec![decorators, target, key, desc],
+ ..Default::default()
+ }
+ .into();
+
+ if has_private_access {
+ self.appended_private_access_exprs.push(expr);
+ } else {
+ self.appended_exprs.push(expr);
+ }
  }
 }
 
@@ -235,6 +258,8 @@ impl Visit for TscDecorator {
 
 impl VisitMut for TscDecorator {
  fn visit_mut_class(&mut self, n: &mut Class) {
+ let appended_private = self.appended_private_access_exprs.take();
+
  n.visit_mut_with(&mut ParamMetadata);
 
  if self.metadata {
@@ -245,6 +270,32 @@ impl VisitMut for TscDecorator {
 
  n.visit_mut_children_with(self);
 
+ let appended_private =
+ mem::replace(&mut self.appended_private_access_exprs, appended_private);
+
+ if !appended_private.is_empty() {
+ let expr = if appended_private.len() == 1 {
+ *appended_private.into_iter().next().unwrap()
+ } else {
+ SeqExpr {
+ exprs: appended_private,
+ ..Default::default()
+ }
+ .into()
+ };
+
+ n.body.push(
+ StaticBlock {
+ body: BlockStmt {
+ stmts: vec![expr.into_stmt()],
+ ..Default::default()
+ },
+ ..Default::default()
+ }
+ .into(),
+ )
+ }
+
  if let Some(class_name) = self.class_name.clone() {
  if !n.decorators.is_empty() {
  let decorators = ArrayLit {