fix(es/transform_base): should add correct parens for optioanl chaini…

…ng expression

crates/swc/tests/fixture/issues-6xxx/6459/1/input/.swcrc

@@ -0,0 +1,10 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "typescript"
+        },
+        "target": "es2020",
+        "loose": false
+    },
+    "isModule": true
+}

crates/swc/tests/fixture/issues-6xxx/6459/1/input/index.ts

@@ -0,0 +1 @@
+(myValue.children?.children[0] as ChildType).value = 'My Value';

crates/swc/tests/fixture/issues-6xxx/6459/1/output/index.ts

@@ -0,0 +1 @@
+(myValue.children?.children)[0].value = 'My Value';

crates/swc/tests/fixture/issues-6xxx/6459/2/input/.swcrc

@@ -0,0 +1,10 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "typescript"
+        },
+        "target": "es2020",
+        "loose": false
+    },
+    "isModule": true
+}

crates/swc/tests/fixture/issues-6xxx/6459/2/input/index.ts

@@ -0,0 +1 @@
+(foo?.bar.baz?.bax).faz = 1

crates/swc/tests/fixture/issues-6xxx/6459/2/output/index.ts

@@ -0,0 +1 @@
+(foo?.bar.baz?.bax).faz = 1;

crates/swc/tests/fixture/issues-6xxx/6459/3/input/.swcrc

@@ -0,0 +1,10 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "typescript"
+        },
+        "target": "es2020",
+        "loose": false
+    },
+    "isModule": true
+}

crates/swc/tests/fixture/issues-6xxx/6459/3/input/index.ts

@@ -0,0 +1 @@
+(foo?.bar.bar.bar?.baz.baz.baz).foo.baz = 1

crates/swc/tests/fixture/issues-6xxx/6459/3/output/index.ts

@@ -0,0 +1 @@
+(foo?.bar.bar.bar?.baz).baz.baz.foo.baz = 1;

crates/swc_ecma_transforms_base/src/fixer.rs

@@ -16,6 +16,7 @@ pub fn fixer(comments: Option<&dyn Comments>) -> impl '_ + Fold + VisitMut {
         ctx: Default::default(),
         span_map: Default::default(),
         in_for_stmt_head: Default::default(),
+        in_assign_lhs: Default::default(),
         remove_only: false,
     })
 }
@@ -26,6 +27,7 @@ pub fn paren_remover(comments: Option<&dyn Comments>) -> impl '_ + Fold + VisitM
         ctx: Default::default(),
         span_map: Default::default(),
         in_for_stmt_head: Default::default(),
+        in_assign_lhs: Default::default(),
         remove_only: true,
     })
 }
@@ -40,6 +42,7 @@ struct Fixer<'a> {
     span_map: FxHashMap<Span, Span>,
 
     in_for_stmt_head: bool,
+    in_assign_lhs: bool,
 
     remove_only: bool,
 }
@@ -152,12 +155,18 @@ impl VisitMut for Fixer<'_> {
     }
 
     fn visit_mut_assign_expr(&mut self, expr: &mut AssignExpr) {
+        let old = self.in_assign_lhs;
+
+        self.in_assign_lhs = true;
         expr.left.visit_mut_with(self);
 
         let ctx = self.ctx;
         self.ctx = Context::FreeExpr;
+        self.in_assign_lhs = false;
         expr.right.visit_mut_with(self);
+
         self.ctx = ctx;
+        self.in_assign_lhs = old;
 
         fn rhs_need_paren(e: &Expr) -> bool {
             match e {
@@ -170,6 +179,34 @@ impl VisitMut for Fixer<'_> {
         if rhs_need_paren(&expr.right) {
             self.wrap(&mut expr.right);
         }
+
+        fn find_nearest_opt_chain_as_obj(e: &mut Expr) -> Option<&mut Expr> {
+            match e {
+                Expr::Member(MemberExpr { obj, .. }) => {
+                    if obj.is_opt_chain() {
+                        Some(obj)
+                    } else {
+                        find_nearest_opt_chain_as_obj(obj)
+                    }
+                }
+                _ => None,
+            }
+        }
+
+        let lhs_expr = match &mut expr.left {
+            PatOrExpr::Expr(e) => Some(e),
+            PatOrExpr::Pat(pat) => {
+                if let Pat::Expr(e) = pat.as_mut() {
+                    Some(e)
+                } else {
+                    None
+                }
+            }
+        };
+
+        if let Some(e) = lhs_expr.and_then(|e| find_nearest_opt_chain_as_obj(e)) {
+            self.wrap(e)
+        };
     }
 
     fn visit_mut_assign_pat(&mut self, node: &mut AssignPat) {
@@ -440,7 +477,7 @@ impl VisitMut for Fixer<'_> {
         e.visit_mut_children_with(self);
 
         self.ctx = ctx;
-        self.wrap_with_paren_if_required(e)
+        self.wrap_with_paren_if_required(e);
     }
 
     fn visit_mut_expr_or_spread(&mut self, e: &mut ExprOrSpread) {