From 4b33d41fabf841dfc31c6f44d94e4651239ab667 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Donny/=EA=B0=95=EB=8F=99=EC=9C=A4?= <kdy1997.dev@gmail.com>
Date: Tue, 29 Aug 2023 14:45:13 +0900
Subject: [PATCH] fix(es/compat): Make `SwitchCase` handler of `block-scoping`
 stateless (#7888)

**Related issue:**

 - Closes #7885
---
 .../fixture/issues-7xxx/7885/input/.swcrc     | 19 ++++++++++++++++
 .../tests/fixture/issues-7xxx/7885/input/1.js | 12 ++++++++++
 .../fixture/issues-7xxx/7885/output/1.js      | 17 ++++++++++++++
 .../src/es2015/block_scoping/mod.rs           | 22 +++++++++++++------
 .../src/es2015/for_of.rs                      |  2 +-
 5 files changed, 64 insertions(+), 8 deletions(-)
 create mode 100644 crates/swc/tests/fixture/issues-7xxx/7885/input/.swcrc
 create mode 100644 crates/swc/tests/fixture/issues-7xxx/7885/input/1.js
 create mode 100644 crates/swc/tests/fixture/issues-7xxx/7885/output/1.js

diff --git a/crates/swc/tests/fixture/issues-7xxx/7885/input/.swcrc b/crates/swc/tests/fixture/issues-7xxx/7885/input/.swcrc
new file mode 100644
index 000000000000..887e89d7affc
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-7xxx/7885/input/.swcrc
@@ -0,0 +1,19 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "typescript",
+            "tsx": false
+        },
+        "target": "es5",
+        "loose": false,
+        "minify": {
+            "compress": false,
+            "mangle": false
+        }
+    },
+    "module": {
+        "type": "es6"
+    },
+    "minify": false,
+    "isModule": true
+}
\ No newline at end of file
diff --git a/crates/swc/tests/fixture/issues-7xxx/7885/input/1.js b/crates/swc/tests/fixture/issues-7xxx/7885/input/1.js
new file mode 100644
index 000000000000..d4574a17ba8a
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-7xxx/7885/input/1.js
@@ -0,0 +1,12 @@
+export const loopError = () => {
+    const stack: number[] = [1];
+    while (stack.shift() !== undefined) {
+        const object = 1;
+        [].map((): number => object);
+    }
+    const kind = 0;
+    switch (kind) {
+        case 0:
+            break;
+    }
+};
\ No newline at end of file
diff --git a/crates/swc/tests/fixture/issues-7xxx/7885/output/1.js b/crates/swc/tests/fixture/issues-7xxx/7885/output/1.js
new file mode 100644
index 000000000000..5f673180859c
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-7xxx/7885/output/1.js
@@ -0,0 +1,17 @@
+export var loopError = function() {
+    var _loop = function() {
+        var object = 1;
+        [].map(function() {
+            return object;
+        });
+    };
+    var stack = [
+        1
+    ];
+    while(stack.shift() !== undefined)_loop();
+    var kind = 0;
+    switch(kind){
+        case 0:
+            break;
+    }
+};
diff --git a/crates/swc_ecma_transforms_compat/src/es2015/block_scoping/mod.rs b/crates/swc_ecma_transforms_compat/src/es2015/block_scoping/mod.rs
index 4c80ceefd3dd..ce18711f7e35 100644
--- a/crates/swc_ecma_transforms_compat/src/es2015/block_scoping/mod.rs
+++ b/crates/swc_ecma_transforms_compat/src/es2015/block_scoping/mod.rs
@@ -431,13 +431,6 @@ impl VisitMut for BlockScoping {
         self.handle_capture_of_vars(&mut node.body);
     }
 
-    fn visit_mut_while_stmt(&mut self, node: &mut WhileStmt) {
-        self.visit_mut_with_scope(ScopeKind::new_loop(), &mut node.body);
-
-        node.test.visit_mut_with(self);
-        self.handle_capture_of_vars(&mut node.body);
-    }
-
     fn visit_mut_for_in_stmt(&mut self, node: &mut ForInStmt) {
         let blockifyed = self.blockify_for_stmt_body(&mut node.body);
         let lexical_var = if let ForHead::VarDecl(decl) = &node.left {
@@ -544,6 +537,14 @@ impl VisitMut for BlockScoping {
         self.visit_mut_stmt_like(n);
     }
 
+    fn visit_mut_switch_case(&mut self, n: &mut SwitchCase) {
+        let old_vars = self.vars.take();
+
+        n.visit_mut_children_with(self);
+
+        self.vars = old_vars;
+    }
+
     fn visit_mut_var_decl(&mut self, var: &mut VarDecl) {
         let old = self.var_decl_kind;
         self.var_decl_kind = var.kind;
@@ -569,6 +570,13 @@ impl VisitMut for BlockScoping {
             }
         }
     }
+
+    fn visit_mut_while_stmt(&mut self, node: &mut WhileStmt) {
+        self.visit_mut_with_scope(ScopeKind::new_loop(), &mut node.body);
+
+        node.test.visit_mut_with(self);
+        self.handle_capture_of_vars(&mut node.body);
+    }
 }
 
 impl BlockScoping {
diff --git a/crates/swc_ecma_transforms_compat/src/es2015/for_of.rs b/crates/swc_ecma_transforms_compat/src/es2015/for_of.rs
index b5094439342b..d7ddb6be3842 100644
--- a/crates/swc_ecma_transforms_compat/src/es2015/for_of.rs
+++ b/crates/swc_ecma_transforms_compat/src/es2015/for_of.rs
@@ -670,7 +670,7 @@ impl VisitMut for ForOf {
                         *s = self.fold_for_stmt(Some(label.clone()), stmt.take());
                     }
                     _ => {
-                        body.visit_mut_children_with(self);
+                        body.visit_mut_with(self);
                     }
                 }
             }