Do not check for await expression and always output yield await

Author: Artem Tyurin

src/compiler/transformers/esnext.ts

@@ -143,19 +143,19 @@ namespace ts {
                     );
                 }
 
-                if (node.expression && node.expression.kind !== SyntaxKind.AwaitExpression) {
-                    return setOriginalNode(
-                        setTextRange(
-                            createYield(
-                                createDownlevelAwait(
-                                    visitNode(node.expression, visitor, isExpression)
-                                )
-                            ),
-                            node
+                return setOriginalNode(
+                    setTextRange(
+                        createYield(
+                            createDownlevelAwait(
+                                node.expression
+                                    ? visitNode(node.expression, visitor, isExpression)
+                                    : createVoidZero()
+                            )
                         ),
                         node
-                    );
-                }
+                    ),
+                    node
+                );
             }
 
             return visitEachChild(node, visitor, context);

tests/baselines/reference/emitter.asyncGenerators.classMethods.es2015.js

@@ -95,7 +95,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 class C2 {
     f() {
         return __asyncGenerator(this, arguments, function* f_1() {
-            const x = yield;
+            const x = yield yield __await(void 0);
         });
     }
 }

tests/baselines/reference/emitter.asyncGenerators.classMethods.es5.js

@@ -160,8 +160,9 @@ var C2 = /** @class */ (function () {
             var x;
             return __generator(this, function (_a) {
                 switch (_a.label) {
-                    case 0: return [4 /*yield*/];
-                    case 1:
+                    case 0: return [4 /*yield*/, __await(void 0)];
+                    case 1: return [4 /*yield*/, _a.sent()];
+                    case 2:
                         x = _a.sent();
                         return [2 /*return*/];
                 }

tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es2015.js

@@ -61,7 +61,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 };
 function f2() {
     return __asyncGenerator(this, arguments, function* f2_1() {
-        const x = yield;
+        const x = yield yield __await(void 0);
     });
 }
 //// [F3.js]

tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es5.js

@@ -121,8 +121,9 @@ function f2() {
         var x;
         return __generator(this, function (_a) {
             switch (_a.label) {
-                case 0: return [4 /*yield*/];
-                case 1:
+                case 0: return [4 /*yield*/, __await(void 0)];
+                case 1: return [4 /*yield*/, _a.sent()];
+                case 2:
                     x = _a.sent();
                     return [2 /*return*/];
             }

tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es2015.js

@@ -61,7 +61,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 };
 const f2 = function () {
     return __asyncGenerator(this, arguments, function* () {
-        const x = yield;
+        const x = yield yield __await(void 0);
     });
 };
 //// [F3.js]

tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es5.js

@@ -121,8 +121,9 @@ var f2 = function () {
         var x;
         return __generator(this, function (_a) {
             switch (_a.label) {
-                case 0: return [4 /*yield*/];
-                case 1:
+                case 0: return [4 /*yield*/, __await(void 0)];
+                case 1: return [4 /*yield*/, _a.sent()];
+                case 2:
                     x = _a.sent();
                     return [2 /*return*/];
             }

tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es2015.js

@@ -78,7 +78,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 const o2 = {
     f() {
         return __asyncGenerator(this, arguments, function* f_1() {
-            const x = yield;
+            const x = yield yield __await(void 0);
         });
     }
 };

tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es5.js

@@ -138,8 +138,9 @@ var o2 = {
             var x;
             return __generator(this, function (_a) {
                 switch (_a.label) {
-                    case 0: return [4 /*yield*/];
-                    case 1:
+                    case 0: return [4 /*yield*/, __await(void 0)];
+                    case 1: return [4 /*yield*/, _a.sent()];
+                    case 2:
                         x = _a.sent();
                         return [2 /*return*/];
                 }