fix(es/compat): Handle nested functions in private_field (#3355)

crates/swc_ecma_transforms_compat/src/es2022/class_properties/private_field.rs

@@ -1,4 +1,4 @@
-use std::{iter, mem};
+use std::iter;
 use swc_atoms::JsWord;
 use swc_common::{collections::AHashSet, util::take::Take, Mark, Spanned, SyntaxContext, DUMMY_SP};
 use swc_ecma_ast::*;
@@ -98,7 +98,8 @@ pub(super) struct FieldAccessFolder<'a> {
 macro_rules! take_vars {
     ($name:ident, $T:tt) => {
         fn $name(&mut self, f: &mut $T) {
-            assert!(self.vars.is_empty());
+            let old_var = self.vars.take();
+
             if f.body.is_none() {
                 return;
             }
@@ -111,12 +112,14 @@ macro_rules! take_vars {
                     Stmt::Decl(Decl::Var(VarDecl {
                         span: DUMMY_SP,
                         kind: VarDeclKind::Var,
-                        decls: mem::take(&mut self.vars),
+                        decls: self.vars.take(),
 
                         declare: false,
                     })),
                 )
             }
+
+            self.vars = old_var;
         }
     };
 }

crates/swc_ecma_transforms_compat/tests/es2022_class_properties.rs

@@ -5632,6 +5632,57 @@ test!(
     "
 );
 
+test!(
+    syntax(),
+    |_| class_properties(class_properties::Config { loose: false }),
+    issue_3229_1,
+    "
+class A {
+  B() {
+    1;
+    C.#D++;
+    E(function() {});
+  }
+}
+  ",
+    "
+class A {
+    B() {
+        var _C, _this_D;
+        1;
+        _classPrivateFieldSet(_C = C, _D, (_this_D = +_classPrivateFieldGet(_C, _D)) + 1), _this_D;
+        E(function() {});
+    }
+}
+  "
+);
+
+test!(
+    syntax(),
+    |_| class_properties(class_properties::Config { loose: false }),
+    issue_3229_2,
+    "
+class A {
+    foo() {
+        A.#b += 123
+        class B {
+            foo() {}
+        }
+    }
+}
+",
+    "
+class A {
+    foo() {
+        var _A;
+        _classPrivateFieldSet(_A = A, _b, _classPrivateFieldGet(_A, _b) + 123);
+        class B {
+            foo() {}
+        }
+    }
+}
+"
+);
 #[testing::fixture("tests/fixture/classes/**/exec.js")]
 fn exec(input: PathBuf) {
     let src = read_to_string(&input).unwrap();