From a2328edced1fcd94802874598cfd79fbc6665510 Mon Sep 17 00:00:00 2001
From: Lucas Azzola <derflatulator@gmail.com>
Date: Thu, 15 Jun 2017 09:34:12 +1000
Subject: [PATCH] TypeScript: keep parens around with yield/await non-null
 assertion, fixes #2137 (#2149)

---
 src/fast-path.js                                 |  4 +++-
 .../__snapshots__/jsfmt.spec.js.snap             | 16 ++++++++++++++++
 tests/typescript_non_null/parens.ts              |  8 ++++++++
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/fast-path.js b/src/fast-path.js
index fd41810d..c734de4d 100644
--- a/src/fast-path.js
+++ b/src/fast-path.js
@@ -385,7 +385,8 @@ FastPath.prototype.needsParens = function(options) {
       if (
         parent.type === "UnaryExpression" ||
         parent.type === "AwaitExpression" ||
-        parent.type === "TSAsExpression"
+        parent.type === "TSAsExpression" ||
+        parent.type === "TSNonNullExpression"
       ) {
         return true;
       }
@@ -398,6 +399,7 @@ FastPath.prototype.needsParens = function(options) {
         case "SpreadElement":
         case "SpreadProperty":
         case "TSAsExpression":
+        case "TSNonNullExpression":
           return true;
 
         case "MemberExpression":
diff --git a/tests/typescript_non_null/__snapshots__/jsfmt.spec.js.snap b/tests/typescript_non_null/__snapshots__/jsfmt.spec.js.snap
index b5900514..6a27e7eb 100644
--- a/tests/typescript_non_null/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/typescript_non_null/__snapshots__/jsfmt.spec.js.snap
@@ -3,8 +3,24 @@
 exports[`parens.ts 1`] = `
 (a ? b : c) ![tokenKey];
 (a || b) ![tokenKey];
+
+async function f() {
+    return (await foo())!;
+}
+
+function* g() {
+    return (yield * foo())!;
+}
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 (a ? b : c)![tokenKey];
 (a || b)![tokenKey];
 
+async function f() {
+  return (await foo())!;
+}
+
+function* g() {
+  return (yield* foo())!;
+}
+
 `;
diff --git a/tests/typescript_non_null/parens.ts b/tests/typescript_non_null/parens.ts
index 2f72c110..24d3d108 100644
--- a/tests/typescript_non_null/parens.ts
+++ b/tests/typescript_non_null/parens.ts
@@ -1,2 +1,10 @@
 (a ? b : c) ![tokenKey];
 (a || b) ![tokenKey];
+
+async function f() {
+    return (await foo())!;
+}
+
+function* g() {
+    return (yield * foo())!;
+}