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 1/5] 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 774cea60e09a8..8545273afecc9 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 0000000000000..8833a6aa97224
--- /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 0000000000000..b6ee77ac793f9
--- /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 0000000000000..7b6d8ef035bb7
--- /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 0000000000000..64e96be70f327
--- /dev/null
+++ b/tests/cases/compiler/castOfAwait.ts
@@ -0,0 +1,4 @@
+// @target: es6
+async function f() {
+    return <number> await 0;
+}

From bc5c7b654ad876f7a75422c58cbbc2d331bdf5f7 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Fri, 22 Jul 2016 13:33:22 -0700
Subject: [PATCH 2/5] More tests

---
 src/compiler/parser.ts                        |  1 +
 tests/baselines/reference/castOfAwait.js      | 10 ++++++--
 tests/baselines/reference/castOfAwait.symbols |  5 +++-
 tests/baselines/reference/castOfAwait.types   | 24 +++++++++++++++++--
 .../reference/castOfYield.errors.txt          | 12 ++++++++++
 tests/baselines/reference/castOfYield.js      | 15 ++++++++++++
 tests/cases/compiler/castOfAwait.ts           |  5 +++-
 tests/cases/compiler/castOfYield.ts           |  5 ++++
 8 files changed, 71 insertions(+), 6 deletions(-)
 create mode 100644 tests/baselines/reference/castOfYield.errors.txt
 create mode 100644 tests/baselines/reference/castOfYield.js
 create mode 100644 tests/cases/compiler/castOfYield.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 8545273afecc9..61c7698c59d0d 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -3386,6 +3386,7 @@ namespace ts {
          *      6) - UnaryExpression[?yield]
          *      7) ~ UnaryExpression[?yield]
          *      8) ! UnaryExpression[?yield]
+         *      9) await AwaitExpression[?yield]
          */
         function parseSimpleUnaryExpression(): UnaryExpression {
             switch (token) {
diff --git a/tests/baselines/reference/castOfAwait.js b/tests/baselines/reference/castOfAwait.js
index 8833a6aa97224..9d1399d9d65f3 100644
--- a/tests/baselines/reference/castOfAwait.js
+++ b/tests/baselines/reference/castOfAwait.js
@@ -1,6 +1,9 @@
 //// [castOfAwait.ts]
 async function f() {
-    return <number> await 0;
+    <number> await 0;
+    typeof await 0;
+    void await 0;
+    await void <string> typeof <number> void await 0;
 }
 
 
@@ -15,6 +18,9 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 };
 function f() {
     return __awaiter(this, void 0, void 0, function* () {
-        return yield 0;
+        yield 0;
+        typeof yield 0;
+        void yield 0;
+        yield void typeof void yield 0;
     });
 }
diff --git a/tests/baselines/reference/castOfAwait.symbols b/tests/baselines/reference/castOfAwait.symbols
index b6ee77ac793f9..d0bca9f38c713 100644
--- a/tests/baselines/reference/castOfAwait.symbols
+++ b/tests/baselines/reference/castOfAwait.symbols
@@ -2,6 +2,9 @@
 async function f() {
 >f : Symbol(f, Decl(castOfAwait.ts, 0, 0))
 
-    return <number> await 0;
+    <number> await 0;
+    typeof await 0;
+    void await 0;
+    await void <string> typeof <number> void await 0;
 }
 
diff --git a/tests/baselines/reference/castOfAwait.types b/tests/baselines/reference/castOfAwait.types
index 7b6d8ef035bb7..ba1590fe03d95 100644
--- a/tests/baselines/reference/castOfAwait.types
+++ b/tests/baselines/reference/castOfAwait.types
@@ -1,10 +1,30 @@
 === tests/cases/compiler/castOfAwait.ts ===
 async function f() {
->f : () => Promise<number>
+>f : () => Promise<void>
 
-    return <number> await 0;
+    <number> await 0;
 ><number> await 0 : number
 >await 0 : number
+>0 : number
+
+    typeof await 0;
+>typeof await 0 : string
+>await 0 : number
+>0 : number
+
+    void await 0;
+>void await 0 : undefined
+>await 0 : number
+>0 : number
+
+    await void <string> typeof <number> void await 0;
+>await void <string> typeof <number> void await 0 : any
+>void <string> typeof <number> void await 0 : undefined
+><string> typeof <number> void await 0 : string
+>typeof <number> void await 0 : string
+><number> void await 0 : number
+>void await 0 : undefined
+>await 0 : number
 >0 : number
 }
 
diff --git a/tests/baselines/reference/castOfYield.errors.txt b/tests/baselines/reference/castOfYield.errors.txt
new file mode 100644
index 0000000000000..abafe67878430
--- /dev/null
+++ b/tests/baselines/reference/castOfYield.errors.txt
@@ -0,0 +1,12 @@
+tests/cases/compiler/castOfYield.ts(4,14): error TS1109: Expression expected.
+
+
+==== tests/cases/compiler/castOfYield.ts (1 errors) ====
+    function* f() {
+        <number> (yield 0);
+        // Unlike await, yield is not allowed to appear in a simple unary expression.
+        <number> yield 0;
+                 ~~~~~
+!!! error TS1109: Expression expected.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/castOfYield.js b/tests/baselines/reference/castOfYield.js
new file mode 100644
index 0000000000000..652cf28e9e1f0
--- /dev/null
+++ b/tests/baselines/reference/castOfYield.js
@@ -0,0 +1,15 @@
+//// [castOfYield.ts]
+function* f() {
+    <number> (yield 0);
+    // Unlike await, yield is not allowed to appear in a simple unary expression.
+    <number> yield 0;
+}
+
+
+//// [castOfYield.js]
+function f() {
+    (yield 0);
+    // Unlike await, yield is not allowed to appear in a simple unary expression.
+    ;
+    yield 0;
+}
diff --git a/tests/cases/compiler/castOfAwait.ts b/tests/cases/compiler/castOfAwait.ts
index 64e96be70f327..6a152226ea215 100644
--- a/tests/cases/compiler/castOfAwait.ts
+++ b/tests/cases/compiler/castOfAwait.ts
@@ -1,4 +1,7 @@
 // @target: es6
 async function f() {
-    return <number> await 0;
+    <number> await 0;
+    typeof await 0;
+    void await 0;
+    await void <string> typeof <number> void await 0;
 }
diff --git a/tests/cases/compiler/castOfYield.ts b/tests/cases/compiler/castOfYield.ts
new file mode 100644
index 0000000000000..9a85e6b21c27d
--- /dev/null
+++ b/tests/cases/compiler/castOfYield.ts
@@ -0,0 +1,5 @@
+function* f() {
+    <number> (yield 0);
+    // Unlike await, yield is not allowed to appear in a simple unary expression.
+    <number> yield 0;
+}

From 275dbc7537accc869da2e47d7f62c519ee223ad4 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Fri, 22 Jul 2016 14:01:59 -0700
Subject: [PATCH 3/5] Forbid `await await`

---
 src/compiler/parser.ts                        |  5 ++++-
 .../baselines/reference/awaitAwait.errors.txt | 10 +++++++++
 tests/baselines/reference/awaitAwait.js       | 21 +++++++++++++++++++
 tests/cases/compiler/awaitAwait.ts            |  4 ++++
 4 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/awaitAwait.errors.txt
 create mode 100644 tests/baselines/reference/awaitAwait.js
 create mode 100644 tests/cases/compiler/awaitAwait.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 61c7698c59d0d..9c54de6ba1384 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -3337,7 +3337,10 @@ namespace ts {
         function parseAwaitExpression() {
             const node = <AwaitExpression>createNode(SyntaxKind.AwaitExpression);
             nextToken();
-            node.expression = parseSimpleUnaryExpression();
+            node.expression = token === SyntaxKind.AwaitKeyword
+                // Forbid `await await`
+                ? <UnaryExpression>createMissingNode(SyntaxKind.Identifier, /*reportAtCurrentPosition*/ false, Diagnostics.Expression_expected)
+                : parseSimpleUnaryExpression();
             return finishNode(node);
         }
 
diff --git a/tests/baselines/reference/awaitAwait.errors.txt b/tests/baselines/reference/awaitAwait.errors.txt
new file mode 100644
index 0000000000000..5a04051139c9f
--- /dev/null
+++ b/tests/baselines/reference/awaitAwait.errors.txt
@@ -0,0 +1,10 @@
+tests/cases/compiler/awaitAwait.ts(2,11): error TS1109: Expression expected.
+
+
+==== tests/cases/compiler/awaitAwait.ts (1 errors) ====
+    async function f() {
+        await await 0;
+              ~~~~~
+!!! error TS1109: Expression expected.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/awaitAwait.js b/tests/baselines/reference/awaitAwait.js
new file mode 100644
index 0000000000000..14fb3a11505da
--- /dev/null
+++ b/tests/baselines/reference/awaitAwait.js
@@ -0,0 +1,21 @@
+//// [awaitAwait.ts]
+async function f() {
+    await await 0;
+}
+
+
+//// [awaitAwait.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* () {
+        yield ;
+        yield 0;
+    });
+}
diff --git a/tests/cases/compiler/awaitAwait.ts b/tests/cases/compiler/awaitAwait.ts
new file mode 100644
index 0000000000000..5a405804b0013
--- /dev/null
+++ b/tests/cases/compiler/awaitAwait.ts
@@ -0,0 +1,4 @@
+// @target: es6
+async function f() {
+    await await 0;
+}

From 52fd0334be9439d459757660b4b6cdf1e2778c6d Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Mon, 25 Jul 2016 11:08:02 -0700
Subject: [PATCH 4/5] Allow `await await`

---
 src/compiler/parser.ts                        |  7 ++-----
 .../baselines/reference/awaitAwait.errors.txt | 10 ---------
 tests/baselines/reference/awaitAwait.js       | 21 -------------------
 tests/baselines/reference/castOfAwait.js      |  2 ++
 tests/baselines/reference/castOfAwait.symbols |  1 +
 tests/baselines/reference/castOfAwait.types   |  5 +++++
 tests/cases/compiler/awaitAwait.ts            |  4 ----
 tests/cases/compiler/castOfAwait.ts           |  1 +
 8 files changed, 11 insertions(+), 40 deletions(-)
 delete mode 100644 tests/baselines/reference/awaitAwait.errors.txt
 delete mode 100644 tests/baselines/reference/awaitAwait.js
 delete mode 100644 tests/cases/compiler/awaitAwait.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 9c54de6ba1384..68753fdb63867 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -3337,10 +3337,7 @@ namespace ts {
         function parseAwaitExpression() {
             const node = <AwaitExpression>createNode(SyntaxKind.AwaitExpression);
             nextToken();
-            node.expression = token === SyntaxKind.AwaitKeyword
-                // Forbid `await await`
-                ? <UnaryExpression>createMissingNode(SyntaxKind.Identifier, /*reportAtCurrentPosition*/ false, Diagnostics.Expression_expected)
-                : parseSimpleUnaryExpression();
+            node.expression = parseSimpleUnaryExpression();
             return finishNode(node);
         }
 
@@ -3389,7 +3386,7 @@ namespace ts {
          *      6) - UnaryExpression[?yield]
          *      7) ~ UnaryExpression[?yield]
          *      8) ! UnaryExpression[?yield]
-         *      9) await AwaitExpression[?yield]
+         *      9) [+Await] await AwaitExpression[?yield]
          */
         function parseSimpleUnaryExpression(): UnaryExpression {
             switch (token) {
diff --git a/tests/baselines/reference/awaitAwait.errors.txt b/tests/baselines/reference/awaitAwait.errors.txt
deleted file mode 100644
index 5a04051139c9f..0000000000000
--- a/tests/baselines/reference/awaitAwait.errors.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-tests/cases/compiler/awaitAwait.ts(2,11): error TS1109: Expression expected.
-
-
-==== tests/cases/compiler/awaitAwait.ts (1 errors) ====
-    async function f() {
-        await await 0;
-              ~~~~~
-!!! error TS1109: Expression expected.
-    }
-    
\ No newline at end of file
diff --git a/tests/baselines/reference/awaitAwait.js b/tests/baselines/reference/awaitAwait.js
deleted file mode 100644
index 14fb3a11505da..0000000000000
--- a/tests/baselines/reference/awaitAwait.js
+++ /dev/null
@@ -1,21 +0,0 @@
-//// [awaitAwait.ts]
-async function f() {
-    await await 0;
-}
-
-
-//// [awaitAwait.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* () {
-        yield ;
-        yield 0;
-    });
-}
diff --git a/tests/baselines/reference/castOfAwait.js b/tests/baselines/reference/castOfAwait.js
index 9d1399d9d65f3..95817b7f0e604 100644
--- a/tests/baselines/reference/castOfAwait.js
+++ b/tests/baselines/reference/castOfAwait.js
@@ -4,6 +4,7 @@ async function f() {
     typeof await 0;
     void await 0;
     await void <string> typeof <number> void await 0;
+    await await 0;
 }
 
 
@@ -22,5 +23,6 @@ function f() {
         typeof yield 0;
         void yield 0;
         yield void typeof void yield 0;
+        yield yield 0;
     });
 }
diff --git a/tests/baselines/reference/castOfAwait.symbols b/tests/baselines/reference/castOfAwait.symbols
index d0bca9f38c713..574ee21f7731b 100644
--- a/tests/baselines/reference/castOfAwait.symbols
+++ b/tests/baselines/reference/castOfAwait.symbols
@@ -6,5 +6,6 @@ async function f() {
     typeof await 0;
     void await 0;
     await void <string> typeof <number> void await 0;
+    await await 0;
 }
 
diff --git a/tests/baselines/reference/castOfAwait.types b/tests/baselines/reference/castOfAwait.types
index ba1590fe03d95..ad3597f6c018a 100644
--- a/tests/baselines/reference/castOfAwait.types
+++ b/tests/baselines/reference/castOfAwait.types
@@ -25,6 +25,11 @@ async function f() {
 ><number> void await 0 : number
 >void await 0 : undefined
 >await 0 : number
+>0 : number
+
+    await await 0;
+>await await 0 : number
+>await 0 : number
 >0 : number
 }
 
diff --git a/tests/cases/compiler/awaitAwait.ts b/tests/cases/compiler/awaitAwait.ts
deleted file mode 100644
index 5a405804b0013..0000000000000
--- a/tests/cases/compiler/awaitAwait.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-// @target: es6
-async function f() {
-    await await 0;
-}
diff --git a/tests/cases/compiler/castOfAwait.ts b/tests/cases/compiler/castOfAwait.ts
index 6a152226ea215..fcd8f999e9fa9 100644
--- a/tests/cases/compiler/castOfAwait.ts
+++ b/tests/cases/compiler/castOfAwait.ts
@@ -4,4 +4,5 @@ async function f() {
     typeof await 0;
     void await 0;
     await void <string> typeof <number> void await 0;
+    await await 0;
 }

From 952d2fecc1817eb86d241a9aa6f93ac560be1d27 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Thu, 18 Aug 2016 14:19:17 -0700
Subject: [PATCH 5/5] Fix comment

---
 src/compiler/parser.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 68753fdb63867..361e293011b54 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -3386,7 +3386,7 @@ namespace ts {
          *      6) - UnaryExpression[?yield]
          *      7) ~ UnaryExpression[?yield]
          *      8) ! UnaryExpression[?yield]
-         *      9) [+Await] await AwaitExpression[?yield]
+         *      9) [+Await] await UnaryExpression[?yield]
          */
         function parseSimpleUnaryExpression(): UnaryExpression {
             switch (token) {