From 95e391ec72f289e5049d7601af758bdc7b0dcc69 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Fri, 22 Jul 2016 05:56:05 -0700
Subject: [PATCH] Allow `await` in a simple unary expression

---
 src/compiler/parser.ts                        |  2 ++
 tests/baselines/reference/castOfAwait.js      | 20 +++++++++++++++++++
 tests/baselines/reference/castOfAwait.symbols |  7 +++++++
 tests/baselines/reference/castOfAwait.types   | 10 ++++++++++
 tests/cases/compiler/castOfAwait.ts           |  4 ++++
 5 files changed, 43 insertions(+)
 create mode 100644 tests/baselines/reference/castOfAwait.js
 create mode 100644 tests/baselines/reference/castOfAwait.symbols
 create mode 100644 tests/baselines/reference/castOfAwait.types
 create mode 100644 tests/cases/compiler/castOfAwait.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 774cea60e09..8545273afec 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -3400,6 +3400,8 @@ namespace ts {
                     return parseTypeOfExpression();
                 case SyntaxKind.VoidKeyword:
                     return parseVoidExpression();
+                case SyntaxKind.AwaitKeyword:
+                    return parseAwaitExpression();
                 case SyntaxKind.LessThanToken:
                     // This is modified UnaryExpression grammar in TypeScript
                     //  UnaryExpression (modified):
diff --git a/tests/baselines/reference/castOfAwait.js b/tests/baselines/reference/castOfAwait.js
new file mode 100644
index 00000000000..8833a6aa972
--- /dev/null
+++ b/tests/baselines/reference/castOfAwait.js
@@ -0,0 +1,20 @@
+//// [castOfAwait.ts]
+async function f() {
+    return <number> await 0;
+}
+
+
+//// [castOfAwait.js]
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator.throw(value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments)).next());
+    });
+};
+function f() {
+    return __awaiter(this, void 0, void 0, function* () {
+        return yield 0;
+    });
+}
diff --git a/tests/baselines/reference/castOfAwait.symbols b/tests/baselines/reference/castOfAwait.symbols
new file mode 100644
index 00000000000..b6ee77ac793
--- /dev/null
+++ b/tests/baselines/reference/castOfAwait.symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/castOfAwait.ts ===
+async function f() {
+>f : Symbol(f, Decl(castOfAwait.ts, 0, 0))
+
+    return <number> await 0;
+}
+
diff --git a/tests/baselines/reference/castOfAwait.types b/tests/baselines/reference/castOfAwait.types
new file mode 100644
index 00000000000..7b6d8ef035b
--- /dev/null
+++ b/tests/baselines/reference/castOfAwait.types
@@ -0,0 +1,10 @@
+=== tests/cases/compiler/castOfAwait.ts ===
+async function f() {
+>f : () => Promise<number>
+
+    return <number> await 0;
+><number> await 0 : number
+>await 0 : number
+>0 : number
+}
+
diff --git a/tests/cases/compiler/castOfAwait.ts b/tests/cases/compiler/castOfAwait.ts
new file mode 100644
index 00000000000..64e96be70f3
--- /dev/null
+++ b/tests/cases/compiler/castOfAwait.ts
@@ -0,0 +1,4 @@
+// @target: es6
+async function f() {
+    return <number> await 0;
+}