From 461e6035c1cc4392510431250dc7a9ff2acb44f7 Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Thu, 6 Sep 2018 09:04:37 +0800
Subject: [PATCH] fix(typescript): preserve necessary parens for TSOptionalType
 (#5056)

---
 src/language-js/needs-parens.js                            | 3 ++-
 .../__snapshots__/jsfmt.spec.js.snap                       | 7 +++++++
 tests/typescript_optional_type/complex.ts                  | 1 +
 3 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 tests/typescript_optional_type/complex.ts

diff --git a/src/language-js/needs-parens.js b/src/language-js/needs-parens.js
index d665e7ad..e2ae1bed 100644
--- a/src/language-js/needs-parens.js
+++ b/src/language-js/needs-parens.js
@@ -317,7 +317,8 @@ function needsParens(path, options) {
           parent.type === "TSTypeReference") &&
         (node.typeAnnotation.type === "TSTypeAnnotation" &&
           node.typeAnnotation.typeAnnotation.type !== "TSFunctionType" &&
-          grandParent.type !== "TSTypeOperator")
+          grandParent.type !== "TSTypeOperator" &&
+          grandParent.type !== "TSOptionalType")
       ) {
         return false;
       }
diff --git a/tests/typescript_optional_type/__snapshots__/jsfmt.spec.js.snap b/tests/typescript_optional_type/__snapshots__/jsfmt.spec.js.snap
index feb340e8..3debf7ef 100644
--- a/tests/typescript_optional_type/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/typescript_optional_type/__snapshots__/jsfmt.spec.js.snap
@@ -1,5 +1,12 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`complex.ts - typescript-verify 1`] = `
+type T = [("a" | "b")?];
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+type T = [("a" | "b")?];
+
+`;
+
 exports[`simple.ts - typescript-verify 1`] = `
 type X = [number, string?];
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/tests/typescript_optional_type/complex.ts b/tests/typescript_optional_type/complex.ts
new file mode 100644
index 00000000..f5c170a3
--- /dev/null
+++ b/tests/typescript_optional_type/complex.ts
@@ -0,0 +1 @@
+type T = [("a" | "b")?];