From cdd69d0145d22008448f394e8b39ba98291d87fe Mon Sep 17 00:00:00 2001
From: John Daly <john.daly2@gmail.com>
Date: Sat, 24 Sep 2022 18:29:33 -0700
Subject: [PATCH] fix(es/parser): Allow `as` in destructuring assignment
 (#5948)

---
 crates/swc_ecma_parser/src/parser/expr/tests.rs          | 9 +++++++++
 crates/swc_ecma_parser/src/parser/pat.rs                 | 3 ++-
 .../tests/fixture/issue-5947/input.ts                    | 2 ++
 .../tests/fixture/issue-5947/output.js                   | 2 ++
 4 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/input.ts
 create mode 100644 crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/output.js

diff --git a/crates/swc_ecma_parser/src/parser/expr/tests.rs b/crates/swc_ecma_parser/src/parser/expr/tests.rs
index c79080fb55d..5e650e87fb1 100644
--- a/crates/swc_ecma_parser/src/parser/expr/tests.rs
+++ b/crates/swc_ecma_parser/src/parser/expr/tests.rs
@@ -510,6 +510,15 @@ fn issue_3672_2() {
     );
 }
 
+#[test]
+fn issue_5947() {
+    test_parser(
+        "[a as number, b as number, c as string] = [1, 2, '3']",
+        Syntax::Typescript(Default::default()),
+        |p| p.parse_module(),
+    );
+}
+
 #[bench]
 fn bench_new_expr_ts(b: &mut Bencher) {
     bench_parser(
diff --git a/crates/swc_ecma_parser/src/parser/pat.rs b/crates/swc_ecma_parser/src/parser/pat.rs
index 98bbbac814c..292cf1b7893 100644
--- a/crates/swc_ecma_parser/src/parser/pat.rs
+++ b/crates/swc_ecma_parser/src/parser/pat.rs
@@ -566,7 +566,8 @@ impl<I: Tokens> Parser<I> {
                 | Expr::Fn(..)
                 | Expr::Class(..)
                 | Expr::Paren(..)
-                | Expr::Tpl(..) => {
+                | Expr::Tpl(..)
+                | Expr::TsAs(..) => {
                     if !expr.is_valid_simple_assignment_target(self.ctx().strict) {
                         self.emit_err(span, SyntaxError::NotSimpleAssign)
                     }
diff --git a/crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/input.ts b/crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/input.ts
new file mode 100644
index 00000000000..247f57b43a5
--- /dev/null
+++ b/crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/input.ts
@@ -0,0 +1,2 @@
+let a, b;
+[a as number, b as number] = [1, 2];
diff --git a/crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/output.js b/crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/output.js
new file mode 100644
index 00000000000..4de6b9dcea9
--- /dev/null
+++ b/crates/swc_ecma_transforms_typescript/tests/fixture/issue-5947/output.js
@@ -0,0 +1,2 @@
+let a, b;
+[a, b] = [1, 2];