From f80085c683f035c1944e8320fcbecc2bc60e6628 Mon Sep 17 00:00:00 2001
From: Dunqing <29533304+Dunqing@users.noreply.github.com>
Date: Mon, 4 Nov 2024 14:32:41 +0000
Subject: [PATCH] refactor(transformer/async-to-generator): move handling of
 `MethodDefinition`'s value to `exit_function` (#7105)

Part of #7074

We need to handle this before the `arrow_function` plugin inserts `_this = this` because, in the `async-to-generator` plugin, we will move the body to an inner generator function. However, we don't want `_this = this` moved to the inner generator function as well. So as long as we move first, and then insert, we can fix this problem.

The new semantic error is related to another tricky problem, I will fix it in another PR
---
 .../oxc_transformer/src/es2017/async_to_generator.rs  | 11 +++--------
 crates/oxc_transformer/src/es2017/mod.rs              | 10 +++-------
 crates/oxc_transformer/src/lib.rs                     |  2 +-
 tasks/transform_conformance/snapshots/babel.snap.md   | 10 +++++++++-
 4 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/crates/oxc_transformer/src/es2017/async_to_generator.rs b/crates/oxc_transformer/src/es2017/async_to_generator.rs
index e492e4903..6f8a360c5 100644
--- a/crates/oxc_transformer/src/es2017/async_to_generator.rs
+++ b/crates/oxc_transformer/src/es2017/async_to_generator.rs
@@ -130,14 +130,9 @@ impl<'a, 'ctx> Traverse<'a> for AsyncToGenerator<'a, 'ctx> {
         }
     }
 
-    fn exit_method_definition(
-        &mut self,
-        node: &mut MethodDefinition<'a>,
-        ctx: &mut TraverseCtx<'a>,
-    ) {
-        let function = &mut node.value;
-        if function.r#async && !function.generator && !function.is_typescript_syntax() {
-            self.executor.transform_function_for_method_definition(function, ctx);
+    fn exit_function(&mut self, func: &mut Function<'a>, ctx: &mut TraverseCtx<'a>) {
+        if func.r#async && ctx.parent().is_method_definition() {
+            self.executor.transform_function_for_method_definition(func, ctx);
         }
     }
 }
diff --git a/crates/oxc_transformer/src/es2017/mod.rs b/crates/oxc_transformer/src/es2017/mod.rs
index 10fdc26ad..562969ece 100644
--- a/crates/oxc_transformer/src/es2017/mod.rs
+++ b/crates/oxc_transformer/src/es2017/mod.rs
@@ -1,7 +1,7 @@
 mod async_to_generator;
 mod options;
 
-use oxc_ast::ast::{Expression, Statement};
+use oxc_ast::ast::{Expression, Function, Statement};
 use oxc_traverse::{Traverse, TraverseCtx};
 
 use crate::{es2017::async_to_generator::AsyncToGenerator, TransformCtx};
@@ -30,13 +30,9 @@ impl<'a, 'ctx> Traverse<'a> for ES2017<'a, 'ctx> {
         }
     }
 
-    fn exit_method_definition(
-        &mut self,
-        node: &mut oxc_ast::ast::MethodDefinition<'a>,
-        ctx: &mut TraverseCtx<'a>,
-    ) {
+    fn exit_function(&mut self, node: &mut Function<'a>, ctx: &mut TraverseCtx<'a>) {
         if self.options.async_to_generator {
-            self.async_to_generator.exit_method_definition(node, ctx);
+            self.async_to_generator.exit_function(node, ctx);
         }
     }
 
diff --git a/crates/oxc_transformer/src/lib.rs b/crates/oxc_transformer/src/lib.rs
index f1fd94df7..eff7671fe 100644
--- a/crates/oxc_transformer/src/lib.rs
+++ b/crates/oxc_transformer/src/lib.rs
@@ -276,6 +276,7 @@ impl<'a, 'ctx> Traverse<'a> for TransformerImpl<'a, 'ctx> {
         }
         self.x1_jsx.exit_function(func, ctx);
         self.x2_es2018.exit_function(func, ctx);
+        self.x2_es2017.exit_function(func, ctx);
         self.x3_es2015.exit_function(func, ctx);
     }
 
@@ -333,7 +334,6 @@ impl<'a, 'ctx> Traverse<'a> for TransformerImpl<'a, 'ctx> {
             typescript.exit_method_definition(def, ctx);
         }
         self.x2_es2018.exit_method_definition(def, ctx);
-        self.x2_es2017.exit_method_definition(def, ctx);
     }
 
     fn enter_new_expression(&mut self, expr: &mut NewExpression<'a>, ctx: &mut TraverseCtx<'a>) {
diff --git a/tasks/transform_conformance/snapshots/babel.snap.md b/tasks/transform_conformance/snapshots/babel.snap.md
index a8b05ebe6..22a15bcaf 100644
--- a/tasks/transform_conformance/snapshots/babel.snap.md
+++ b/tasks/transform_conformance/snapshots/babel.snap.md
@@ -1672,7 +1672,15 @@ x Output mismatch
 x Output mismatch
 
 * regression/regression-2765/input.js
-x Output mismatch
+Bindings mismatch:
+after transform: ScopeId(10): []
+rebuilt        : ScopeId(6): ["_this2"]
+Bindings mismatch:
+after transform: ScopeId(4): ["_this2", "c"]
+rebuilt        : ScopeId(7): ["c"]
+Symbol scope ID mismatch for "_this2":
+after transform: SymbolId(8): ScopeId(4)
+rebuilt        : SymbolId(6): ScopeId(6)
 
 
 # babel-plugin-transform-exponentiation-operator (3/4)