From fdd1e1ead7053d17bf51581bad0af2b6d0581a0c Mon Sep 17 00:00:00 2001
From: Dunqing <29533304+Dunqing@users.noreply.github.com>
Date: Mon, 12 Jan 2026 02:54:37 +0000
Subject: [PATCH] fix(formatter): don't wrap parenthesis for type assertion
 when it's an declaration of export default (#17878)

close: #17872
---
 .../src/parentheses/expression.rs              |  3 +--
 .../fixtures/ts/parenthesis/type-assertion.ts  |  1 +
 .../ts/parenthesis/type-assertion.ts.snap      | 18 ++++++++++++++++++
 3 files changed, 20 insertions(+), 2 deletions(-)
 create mode 100644 crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts
 create mode 100644 crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts.snap

diff --git a/crates/oxc_formatter/src/parentheses/expression.rs b/crates/oxc_formatter/src/parentheses/expression.rs
index 9afb6c45751bc..881fbdb50d964 100644
--- a/crates/oxc_formatter/src/parentheses/expression.rs
+++ b/crates/oxc_formatter/src/parentheses/expression.rs
@@ -738,8 +738,7 @@ impl NeedsParentheses<'_> for AstNode<'_, TSTypeAssertion<'_>> {
 fn type_cast_like_needs_parens(span: Span, parent: &AstNodes<'_>) -> bool {
     #[expect(clippy::match_same_arms)] // for better readability
     match parent {
-        AstNodes::ExportDefaultDeclaration(_)
-        | AstNodes::TSTypeAssertion(_)
+        AstNodes::TSTypeAssertion(_)
         | AstNodes::UnaryExpression(_)
         | AstNodes::AwaitExpression(_)
         | AstNodes::TSNonNullExpression(_)
diff --git a/crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts b/crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts
new file mode 100644
index 0000000000000..a5bee976165a0
--- /dev/null
+++ b/crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts
@@ -0,0 +1 @@
+export default <Array>[];
diff --git a/crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts.snap b/crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts.snap
new file mode 100644
index 0000000000000..8119f71f80d43
--- /dev/null
+++ b/crates/oxc_formatter/tests/fixtures/ts/parenthesis/type-assertion.ts.snap
@@ -0,0 +1,18 @@
+---
+source: crates/oxc_formatter/tests/fixtures/mod.rs
+---
+==================== Input ====================
+export default <Array>[];
+
+==================== Output ====================
+------------------
+{ printWidth: 80 }
+------------------
+export default <Array>[];
+
+-------------------
+{ printWidth: 100 }
+-------------------
+export default <Array>[];
+
+===================== End =====================