diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
index 40c63cb7ac9..d6571dfdb75 100644
--- a/src/compiler/factory.ts
+++ b/src/compiler/factory.ts
@@ -1649,28 +1649,36 @@ namespace ts {
      * @param target: result statements array
      * @param source: origin statements array
      * @param ensureUseStrict: boolean determining whether the function need to add prologue-directives
+     * @param visitor: Optional callback used to visit any custom prologue directives.
      */
-    export function addPrologueDirectives(target: Statement[], source: Statement[], ensureUseStrict?: boolean): number {
+    export function addPrologueDirectives(target: Statement[], source: Statement[], ensureUseStrict?: boolean, visitor?: (node: Node) => VisitResult<Node>): number {
         Debug.assert(target.length === 0, "PrologueDirectives should be at the first statement in the target statements array");
         let foundUseStrict = false;
-        for (let i = 0; i < source.length; i++) {
-            if (isPrologueDirective(source[i])) {
-                if (isUseStrictPrologue(source[i] as ExpressionStatement)) {
+        let statementOffset = 0;
+        const numStatements = source.length;
+        while (statementOffset < numStatements) {
+            const statement = source[statementOffset];
+            if (isPrologueDirective(statement)) {
+                if (isUseStrictPrologue(statement as ExpressionStatement)) {
                     foundUseStrict = true;
                 }
-
-                target.push(source[i]);
+                target.push(statement);
             }
             else {
                 if (ensureUseStrict && !foundUseStrict) {
                     target.push(startOnNewLine(createStatement(createLiteral("use strict"))));
+                    foundUseStrict = true;
+                }
+                if (statement.emitFlags & NodeEmitFlags.CustomPrologue) {
+                    target.push(visitor ? visitNode(statement, visitor, isStatement) : statement);
+                }
+                else {
+                    break;
                 }
-
-                return i;
             }
+            statementOffset++;
         }
-
-        return source.length;
+        return statementOffset;
     }
 
     /**
diff --git a/src/compiler/transformers/es6.ts b/src/compiler/transformers/es6.ts
index 110d7440212..7deaa38d148 100644
--- a/src/compiler/transformers/es6.ts
+++ b/src/compiler/transformers/es6.ts
@@ -930,21 +930,27 @@ namespace ts {
             // of an initializer, we must emit that expression to preserve side effects.
             if (name.elements.length > 0) {
                 statements.push(
-                    createVariableStatement(
-                        /*modifiers*/ undefined,
-                        createVariableDeclarationList(
-                            flattenParameterDestructuring(context, parameter, temp, visitor)
-                        )
+                    setNodeEmitFlags(
+                        createVariableStatement(
+                            /*modifiers*/ undefined,
+                            createVariableDeclarationList(
+                                flattenParameterDestructuring(context, parameter, temp, visitor)
+                            )
+                        ),
+                        NodeEmitFlags.CustomPrologue
                     )
                 );
             }
             else if (initializer) {
                 statements.push(
-                    createStatement(
-                        createAssignment(
-                            temp,
-                            visitNode(initializer, visitor, isExpression)
-                        )
+                    setNodeEmitFlags(
+                        createStatement(
+                            createAssignment(
+                                temp,
+                                visitNode(initializer, visitor, isExpression)
+                            )
+                        ),
+                        NodeEmitFlags.CustomPrologue
                     )
                 );
             }
@@ -981,7 +987,7 @@ namespace ts {
                 /*location*/ parameter
             );
             statement.startsOnNewLine = true;
-            setNodeEmitFlags(statement, NodeEmitFlags.NoTokenSourceMaps | NodeEmitFlags.NoTrailingSourceMap);
+            setNodeEmitFlags(statement, NodeEmitFlags.NoTokenSourceMaps | NodeEmitFlags.NoTrailingSourceMap | NodeEmitFlags.CustomPrologue);
             statements.push(statement);
         }
 
@@ -1023,16 +1029,19 @@ namespace ts {
 
             // var param = [];
             statements.push(
-                createVariableStatement(
-                    /*modifiers*/ undefined,
-                    createVariableDeclarationList([
-                        createVariableDeclaration(
-                            declarationName,
-                            /*type*/ undefined,
-                            createArrayLiteral([])
-                        )
-                    ]),
-                    /*location*/ parameter
+                setNodeEmitFlags(
+                    createVariableStatement(
+                        /*modifiers*/ undefined,
+                        createVariableDeclarationList([
+                            createVariableDeclaration(
+                                declarationName,
+                                /*type*/ undefined,
+                                createArrayLiteral([])
+                            )
+                        ]),
+                        /*location*/ parameter
+                    ),
+                    NodeEmitFlags.CustomPrologue
                 )
             );
 
@@ -1065,7 +1074,7 @@ namespace ts {
                 ])
             );
 
-            setNodeEmitFlags(forStatement, NodeEmitFlags.SourceMapAdjustRestParameterLoop);
+            setNodeEmitFlags(forStatement, NodeEmitFlags.SourceMapAdjustRestParameterLoop | NodeEmitFlags.CustomPrologue);
             startOnNewLine(forStatement);
             statements.push(forStatement);
         }
@@ -1090,7 +1099,7 @@ namespace ts {
                     ])
                 );
 
-                setNodeEmitFlags(captureThisStatement, NodeEmitFlags.NoComments);
+                setNodeEmitFlags(captureThisStatement, NodeEmitFlags.NoComments | NodeEmitFlags.CustomPrologue);
                 setSourceMapRange(captureThisStatement, node);
                 statements.push(captureThisStatement);
             }
@@ -1347,7 +1356,7 @@ namespace ts {
             if (isBlock(body)) {
                 // ensureUseStrict is false because no new prologue-directive should be added.
                 // addPrologueDirectives will simply put already-existing directives at the beginning of the target statement-array
-                statementOffset = addPrologueDirectives(statements, body.statements, /*ensureUseStrict*/ false);
+                statementOffset = addPrologueDirectives(statements, body.statements, /*ensureUseStrict*/ false, visitor);
             }
 
             addCaptureThisForNodeIfNeeded(statements, node);
diff --git a/src/compiler/transformers/generators.ts b/src/compiler/transformers/generators.ts
index 234f39550a7..adb62f117ef 100644
--- a/src/compiler/transformers/generators.ts
+++ b/src/compiler/transformers/generators.ts
@@ -309,10 +309,7 @@ namespace ts {
          */
         function visitor(node: Node): VisitResult<Node> {
             const transformFlags = node.transformFlags;
-            if (transformFlags & TransformFlags.ContainsYield) {
-                return visitJavaScriptContainingYield(node);
-            }
-            else if (inStatementContainingYield) {
+            if (inStatementContainingYield) {
                 return visitJavaScriptInStatementContainingYield(node);
             }
             else if (inGeneratorFunctionBody) {
@@ -329,34 +326,6 @@ namespace ts {
             }
         }
 
-        /**
-         * Visits a node that contains a YieldExpression.
-         *
-         * @param node The node to visit.
-         */
-        function visitJavaScriptContainingYield(node: Node): VisitResult<Node> {
-            switch (node.kind) {
-                case SyntaxKind.BinaryExpression:
-                    return visitBinaryExpression(<BinaryExpression>node);
-                case SyntaxKind.ConditionalExpression:
-                    return visitConditionalExpression(<ConditionalExpression>node);
-                case SyntaxKind.YieldExpression:
-                    return visitYieldExpression(<YieldExpression>node);
-                case SyntaxKind.ArrayLiteralExpression:
-                    return visitArrayLiteralExpression(<ArrayLiteralExpression>node);
-                case SyntaxKind.ObjectLiteralExpression:
-                    return visitObjectLiteralExpression(<ObjectLiteralExpression>node);
-                case SyntaxKind.ElementAccessExpression:
-                    return visitElementAccessExpression(<ElementAccessExpression>node);
-                case SyntaxKind.CallExpression:
-                    return visitCallExpression(<CallExpression>node);
-                case SyntaxKind.NewExpression:
-                    return visitNewExpression(<NewExpression>node);
-                default:
-                    return visitJavaScriptInStatementContainingYield(node);
-            }
-        }
-
         /**
          * Visits a node that is contained within a statement that contains yield.
          *
@@ -404,7 +373,10 @@ namespace ts {
                 case SyntaxKind.ReturnStatement:
                     return visitReturnStatement(<ReturnStatement>node);
                 default:
-                    if (node.transformFlags & (TransformFlags.ContainsGenerator | TransformFlags.ContainsYield | TransformFlags.ContainsHoistedDeclarationOrCompletion)) {
+                    if (node.transformFlags & TransformFlags.ContainsYield) {
+                        return visitJavaScriptContainingYield(node);
+                    }
+                    else if (node.transformFlags & (TransformFlags.ContainsGenerator | TransformFlags.ContainsHoistedDeclarationOrCompletion)) {
                         return visitEachChild(node, visitor, context);
                     }
                     else {
@@ -413,6 +385,34 @@ namespace ts {
             }
         }
 
+        /**
+         * Visits a node that contains a YieldExpression.
+         *
+         * @param node The node to visit.
+         */
+        function visitJavaScriptContainingYield(node: Node): VisitResult<Node> {
+            switch (node.kind) {
+                case SyntaxKind.BinaryExpression:
+                    return visitBinaryExpression(<BinaryExpression>node);
+                case SyntaxKind.ConditionalExpression:
+                    return visitConditionalExpression(<ConditionalExpression>node);
+                case SyntaxKind.YieldExpression:
+                    return visitYieldExpression(<YieldExpression>node);
+                case SyntaxKind.ArrayLiteralExpression:
+                    return visitArrayLiteralExpression(<ArrayLiteralExpression>node);
+                case SyntaxKind.ObjectLiteralExpression:
+                    return visitObjectLiteralExpression(<ObjectLiteralExpression>node);
+                case SyntaxKind.ElementAccessExpression:
+                    return visitElementAccessExpression(<ElementAccessExpression>node);
+                case SyntaxKind.CallExpression:
+                    return visitCallExpression(<CallExpression>node);
+                case SyntaxKind.NewExpression:
+                    return visitNewExpression(<NewExpression>node);
+                default:
+                    return visitEachChild(node, visitor, context);
+            }
+        }
+
         /**
          * Visits a generator function.
          *
@@ -572,7 +572,7 @@ namespace ts {
             operationLocations = undefined;
             state = createTempVariable(/*recordTempVariable*/ undefined);
 
-            const statementOffset = addPrologueDirectives(statements, body.statements);
+            const statementOffset = addPrologueDirectives(statements, body.statements, /*ensureUseStrict*/ false, visitor);
 
             // Build the generator
             startLexicalEnvironment();
diff --git a/src/compiler/transformers/module/module.ts b/src/compiler/transformers/module/module.ts
index 7eb86a1143b..ce699630ba7 100644
--- a/src/compiler/transformers/module/module.ts
+++ b/src/compiler/transformers/module/module.ts
@@ -84,7 +84,7 @@ namespace ts {
             startLexicalEnvironment();
 
             const statements: Statement[] = [];
-            const statementOffset = addPrologueDirectives(statements, node.statements, /*ensureUseStrict*/ !compilerOptions.noImplicitUseStrict);
+            const statementOffset = addPrologueDirectives(statements, node.statements, /*ensureUseStrict*/ !compilerOptions.noImplicitUseStrict, visitor);
             addRange(statements, visitNodes(node.statements, visitor, isStatement, statementOffset));
             addRange(statements, endLexicalEnvironment());
             addExportEqualsIfNeeded(statements, /*emitAsReturn*/ false);
@@ -203,7 +203,7 @@ namespace ts {
             startLexicalEnvironment();
 
             const statements: Statement[] = [];
-            const statementOffset = addPrologueDirectives(statements, node.statements, /*ensureUseStrict*/ !compilerOptions.noImplicitUseStrict);
+            const statementOffset = addPrologueDirectives(statements, node.statements, /*ensureUseStrict*/ !compilerOptions.noImplicitUseStrict, visitor);
 
             // Visit each statement of the module body.
             addRange(statements, visitNodes(node.statements, visitor, isStatement, statementOffset));
diff --git a/src/compiler/transformers/module/system.ts b/src/compiler/transformers/module/system.ts
index 1f601ae4b55..8f956c19adc 100644
--- a/src/compiler/transformers/module/system.ts
+++ b/src/compiler/transformers/module/system.ts
@@ -194,7 +194,7 @@ namespace ts {
             startLexicalEnvironment();
 
             // Add any prologue directives.
-            const statementOffset = addPrologueDirectives(statements, node.statements, /*ensureUseStrict*/ !compilerOptions.noImplicitUseStrict);
+            const statementOffset = addPrologueDirectives(statements, node.statements, /*ensureUseStrict*/ !compilerOptions.noImplicitUseStrict, visitSourceElement);
 
             // var __moduleName = context_1 && context_1.id;
             addNode(statements,
diff --git a/src/compiler/transformers/ts.ts b/src/compiler/transformers/ts.ts
index f2157e5a5c0..57de884da33 100644
--- a/src/compiler/transformers/ts.ts
+++ b/src/compiler/transformers/ts.ts
@@ -431,7 +431,7 @@ namespace ts {
                 && (isExternalModule(node) || compilerOptions.isolatedModules)) {
                 startLexicalEnvironment();
                 const statements: Statement[] = [];
-                const statementOffset = addPrologueDirectives(statements, node.statements);
+                const statementOffset = addPrologueDirectives(statements, node.statements, /*ensureUseStrict*/ false, visitor);
                 const externalHelpersModuleName = createUniqueName(externalHelpersModuleNameText);
                 const externalHelpersModuleImport = createImportDeclaration(
                     createImportClause(/*name*/ undefined, createNamespaceImport(externalHelpersModuleName)),
@@ -933,7 +933,7 @@ namespace ts {
             if (ctor.body) {
                 const statements = ctor.body.statements;
                 // add prologue directives to the list (if any)
-                const index = addPrologueDirectives(result, statements);
+                const index = addPrologueDirectives(result, statements, /*ensureUseStrict*/ false, visitor);
                 if (index === statements.length) {
                     // list contains nothing but prologue directives (or empty) - exit
                     return index;
@@ -2235,7 +2235,7 @@ namespace ts {
 
             if (!isArrowFunction) {
                 const statements: Statement[] = [];
-                const statementOffset = addPrologueDirectives(statements, (<Block>node.body).statements);
+                const statementOffset = addPrologueDirectives(statements, (<Block>node.body).statements, /*ensureUseStrict*/ false, visitor);
                 statements.push(
                     createReturn(
                         createAwaiterHelper(
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index e827265dd29..71e4a202b40 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3064,6 +3064,7 @@ namespace ts {
         Indented = 1 << 19,                      // Adds an explicit extra indentation level for class and function bodies when printing (used to match old emitter).
         AsyncFunctionBody = 1 << 20,
         ReuseTempVariableScope = 1 << 21,        // Reuse the existing temp variable scope during emit.
+        CustomPrologue = 1 << 22,                // Treat the statement as if it were a prologue directive (NOTE: Prologue directives are *not* transformed).
 
         // SourceMap Specialization.
         // TODO(rbuckton): These should be removed once source maps are aligned with the old
diff --git a/tests/baselines/reference/asyncFunctionDeclaration10_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration10_es5.errors.txt
new file mode 100644
index 00000000000..dc814e9c887
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration10_es5.errors.txt
@@ -0,0 +1,26 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts(1,20): error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts(1,30): error TS1109: Expression expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts(1,33): error TS1138: Parameter declaration expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts(1,33): error TS2304: Cannot find name 'await'.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts(1,38): error TS1005: ';' expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts(1,39): error TS1128: Declaration or statement expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts(1,53): error TS1109: Expression expected.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts (7 errors) ====
+    async function foo(a = await => await): Promise<void> {
+                       ~~~~~~~~~
+!!! error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
+                                 ~~
+!!! error TS1109: Expression expected.
+                                    ~~~~~
+!!! error TS1138: Parameter declaration expected.
+                                    ~~~~~
+!!! error TS2304: Cannot find name 'await'.
+                                         ~
+!!! error TS1005: ';' expected.
+                                          ~
+!!! error TS1128: Declaration or statement expected.
+                                                        ~
+!!! error TS1109: Expression expected.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration10_es5.js b/tests/baselines/reference/asyncFunctionDeclaration10_es5.js
new file mode 100644
index 00000000000..05ff9daa9da
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration10_es5.js
@@ -0,0 +1,7 @@
+//// [asyncFunctionDeclaration10_es5.ts]
+async function foo(a = await => await): Promise<void> {
+}
+
+//// [asyncFunctionDeclaration10_es5.js]
+await;
+Promise < void  > {};
diff --git a/tests/baselines/reference/asyncFunctionDeclaration11_es5.js b/tests/baselines/reference/asyncFunctionDeclaration11_es5.js
new file mode 100644
index 00000000000..166f4c9c5ca
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration11_es5.js
@@ -0,0 +1,12 @@
+//// [asyncFunctionDeclaration11_es5.ts]
+async function await(): Promise<void> {
+}
+
+//// [asyncFunctionDeclaration11_es5.js]
+function await() {
+    return __awaiter(this, void 0, Promise, function () {
+        return __generator(function (_a) {
+            return [2 /*return*/];
+        });
+    });
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration11_es5.symbols b/tests/baselines/reference/asyncFunctionDeclaration11_es5.symbols
new file mode 100644
index 00000000000..fc20251d567
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration11_es5.symbols
@@ -0,0 +1,5 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration11_es5.ts ===
+async function await(): Promise<void> {
+>await : Symbol(await, Decl(asyncFunctionDeclaration11_es5.ts, 0, 0))
+>Promise : Symbol(Promise, Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --))
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration11_es5.types b/tests/baselines/reference/asyncFunctionDeclaration11_es5.types
new file mode 100644
index 00000000000..fdda0b0a084
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration11_es5.types
@@ -0,0 +1,5 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration11_es5.ts ===
+async function await(): Promise<void> {
+>await : () => Promise<void>
+>Promise : Promise<T>
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration12_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration12_es5.errors.txt
new file mode 100644
index 00000000000..6468ec69716
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration12_es5.errors.txt
@@ -0,0 +1,16 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts(1,24): error TS1005: '(' expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts(1,29): error TS1005: '=' expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts(1,33): error TS2355: A function whose declared type is neither 'void' nor 'any' must return a value.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts(1,47): error TS1005: '=>' expected.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts (4 errors) ====
+    var v = async function await(): Promise<void> { }
+                           ~~~~~
+!!! error TS1005: '(' expected.
+                                ~
+!!! error TS1005: '=' expected.
+                                    ~~~~~~~~~~~~~
+!!! error TS2355: A function whose declared type is neither 'void' nor 'any' must return a value.
+                                                  ~
+!!! error TS1005: '=>' expected.
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration12_es5.js b/tests/baselines/reference/asyncFunctionDeclaration12_es5.js
new file mode 100644
index 00000000000..4123175b22c
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration12_es5.js
@@ -0,0 +1,5 @@
+//// [asyncFunctionDeclaration12_es5.ts]
+var v = async function await(): Promise<void> { }
+
+//// [asyncFunctionDeclaration12_es5.js]
+var v = , await = function () { };
diff --git a/tests/baselines/reference/asyncFunctionDeclaration13_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration13_es5.errors.txt
new file mode 100644
index 00000000000..ce83aabc4be
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration13_es5.errors.txt
@@ -0,0 +1,11 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration13_es5.ts(3,11): error TS2304: Cannot find name 'await'.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration13_es5.ts (1 errors) ====
+    async function foo(): Promise<void> {
+       // Legal to use 'await' in a type context.
+       var v: await;
+              ~~~~~
+!!! error TS2304: Cannot find name 'await'.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration13_es5.js b/tests/baselines/reference/asyncFunctionDeclaration13_es5.js
new file mode 100644
index 00000000000..2ab2f5c7b7b
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration13_es5.js
@@ -0,0 +1,16 @@
+//// [asyncFunctionDeclaration13_es5.ts]
+async function foo(): Promise<void> {
+   // Legal to use 'await' in a type context.
+   var v: await;
+}
+
+
+//// [asyncFunctionDeclaration13_es5.js]
+function foo() {
+    return __awaiter(this, void 0, Promise, function () {
+        var v;
+        return __generator(function (_a) {
+            return [2 /*return*/];
+        });
+    });
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration14_es5.js b/tests/baselines/reference/asyncFunctionDeclaration14_es5.js
new file mode 100644
index 00000000000..d0e747e0f84
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration14_es5.js
@@ -0,0 +1,13 @@
+//// [asyncFunctionDeclaration14_es5.ts]
+async function foo(): Promise<void> {
+  return;
+}
+
+//// [asyncFunctionDeclaration14_es5.js]
+function foo() {
+    return __awaiter(this, void 0, Promise, function () {
+        return __generator(function (_a) {
+            return [2 /*return*/];
+        });
+    });
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration14_es5.symbols b/tests/baselines/reference/asyncFunctionDeclaration14_es5.symbols
new file mode 100644
index 00000000000..1126618cfe7
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration14_es5.symbols
@@ -0,0 +1,7 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration14_es5.ts ===
+async function foo(): Promise<void> {
+>foo : Symbol(foo, Decl(asyncFunctionDeclaration14_es5.ts, 0, 0))
+>Promise : Symbol(Promise, Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --))
+
+  return;
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration14_es5.types b/tests/baselines/reference/asyncFunctionDeclaration14_es5.types
new file mode 100644
index 00000000000..5c2575c9cc9
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration14_es5.types
@@ -0,0 +1,7 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration14_es5.ts ===
+async function foo(): Promise<void> {
+>foo : () => Promise<void>
+>Promise : Promise<T>
+
+  return;
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration15_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration15_es5.errors.txt
new file mode 100644
index 00000000000..752feb261b3
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration15_es5.errors.txt
@@ -0,0 +1,59 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(6,16): error TS1055: Type '{}' is not a valid async function return type.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(7,16): error TS1055: Type 'any' is not a valid async function return type.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(8,16): error TS1055: Type 'number' is not a valid async function return type.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(9,16): error TS1055: Type 'PromiseLike' is not a valid async function return type.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(10,16): error TS1055: Type 'typeof Thenable' is not a valid async function return type.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(10,16): error TS1055: Type 'typeof Thenable' is not a valid async function return type.
+  Type 'Thenable' is not assignable to type 'PromiseLike<any>'.
+    Types of property 'then' are incompatible.
+      Type '() => void' is not assignable to type '{ <TResult>(onfulfilled?: (value: any) => TResult | PromiseLike<TResult>, onrejected?: (reason: any) => TResult | PromiseLike<TResult>): PromiseLike<TResult>; <TResult>(onfulfilled?: (value: any) => TResult | PromiseLike<TResult>, onrejected?: (reason: any) => void): PromiseLike<TResult>; }'.
+        Type 'void' is not assignable to type 'PromiseLike<any>'.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(17,16): error TS1059: Return expression in async function does not have a valid callable 'then' member.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts(23,25): error TS1058: Operand for 'await' does not have a valid callable 'then' member.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts (8 errors) ====
+    declare class Thenable { then(): void; }
+    declare let a: any;
+    declare let obj: { then: string; };
+    declare let thenable: Thenable;
+    async function fn1() { } // valid: Promise<void>
+    async function fn2(): { } { } // error
+                   ~~~
+!!! error TS1055: Type '{}' is not a valid async function return type.
+    async function fn3(): any { } // error
+                   ~~~
+!!! error TS1055: Type 'any' is not a valid async function return type.
+    async function fn4(): number { } // error
+                   ~~~
+!!! error TS1055: Type 'number' is not a valid async function return type.
+    async function fn5(): PromiseLike<void> { } // error
+                   ~~~
+!!! error TS1055: Type 'PromiseLike' is not a valid async function return type.
+    async function fn6(): Thenable { } // error
+                   ~~~
+!!! error TS1055: Type 'typeof Thenable' is not a valid async function return type.
+                   ~~~
+!!! error TS1055: Type 'typeof Thenable' is not a valid async function return type.
+!!! error TS1055:   Type 'Thenable' is not assignable to type 'PromiseLike<any>'.
+!!! error TS1055:     Types of property 'then' are incompatible.
+!!! error TS1055:       Type '() => void' is not assignable to type '{ <TResult>(onfulfilled?: (value: any) => TResult | PromiseLike<TResult>, onrejected?: (reason: any) => TResult | PromiseLike<TResult>): PromiseLike<TResult>; <TResult>(onfulfilled?: (value: any) => TResult | PromiseLike<TResult>, onrejected?: (reason: any) => void): PromiseLike<TResult>; }'.
+!!! error TS1055:         Type 'void' is not assignable to type 'PromiseLike<any>'.
+    async function fn7() { return; } // valid: Promise<void>
+    async function fn8() { return 1; } // valid: Promise<number>
+    async function fn9() { return null; } // valid: Promise<any>
+    async function fn10() { return undefined; } // valid: Promise<any>
+    async function fn11() { return a; } // valid: Promise<any>
+    async function fn12() { return obj; } // valid: Promise<{ then: string; }>
+    async function fn13() { return thenable; } // error
+                   ~~~~
+!!! error TS1059: Return expression in async function does not have a valid callable 'then' member.
+    async function fn14() { await 1; } // valid: Promise<void>
+    async function fn15() { await null; } // valid: Promise<void>
+    async function fn16() { await undefined; } // valid: Promise<void>
+    async function fn17() { await a; } // valid: Promise<void>
+    async function fn18() { await obj; } // valid: Promise<void>
+    async function fn19() { await thenable; } // error
+                            ~~~~~~~~~~~~~~
+!!! error TS1058: Operand for 'await' does not have a valid callable 'then' member.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration15_es5.js b/tests/baselines/reference/asyncFunctionDeclaration15_es5.js
new file mode 100644
index 00000000000..47e1fe45c80
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration15_es5.js
@@ -0,0 +1,152 @@
+//// [asyncFunctionDeclaration15_es5.ts]
+declare class Thenable { then(): void; }
+declare let a: any;
+declare let obj: { then: string; };
+declare let thenable: Thenable;
+async function fn1() { } // valid: Promise<void>
+async function fn2(): { } { } // error
+async function fn3(): any { } // error
+async function fn4(): number { } // error
+async function fn5(): PromiseLike<void> { } // error
+async function fn6(): Thenable { } // error
+async function fn7() { return; } // valid: Promise<void>
+async function fn8() { return 1; } // valid: Promise<number>
+async function fn9() { return null; } // valid: Promise<any>
+async function fn10() { return undefined; } // valid: Promise<any>
+async function fn11() { return a; } // valid: Promise<any>
+async function fn12() { return obj; } // valid: Promise<{ then: string; }>
+async function fn13() { return thenable; } // error
+async function fn14() { await 1; } // valid: Promise<void>
+async function fn15() { await null; } // valid: Promise<void>
+async function fn16() { await undefined; } // valid: Promise<void>
+async function fn17() { await a; } // valid: Promise<void>
+async function fn18() { await obj; } // valid: Promise<void>
+async function fn19() { await thenable; } // error
+
+
+//// [asyncFunctionDeclaration15_es5.js]
+function fn1() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/];
+    }); });
+} // valid: Promise<void>
+function fn2() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/];
+    }); });
+} // error
+function fn3() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/];
+    }); });
+} // error
+function fn4() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/];
+    }); });
+} // error
+function fn5() {
+    return __awaiter(this, void 0, PromiseLike, function () { return __generator(function (_a) {
+        return [2 /*return*/];
+    }); });
+} // error
+function fn6() {
+    return __awaiter(this, void 0, Thenable, function () { return __generator(function (_a) {
+        return [2 /*return*/];
+    }); });
+} // error
+function fn7() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/];
+    }); });
+} // valid: Promise<void>
+function fn8() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/, 1];
+    }); });
+} // valid: Promise<number>
+function fn9() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/, null];
+    }); });
+} // valid: Promise<any>
+function fn10() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/, undefined];
+    }); });
+} // valid: Promise<any>
+function fn11() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/, a];
+    }); });
+} // valid: Promise<any>
+function fn12() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/, obj];
+    }); });
+} // valid: Promise<{ then: string; }>
+function fn13() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        return [2 /*return*/, thenable];
+    }); });
+} // error
+function fn14() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, 1];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+} // valid: Promise<void>
+function fn15() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, null];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+} // valid: Promise<void>
+function fn16() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, undefined];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+} // valid: Promise<void>
+function fn17() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, a];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+} // valid: Promise<void>
+function fn18() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, obj];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+} // valid: Promise<void>
+function fn19() {
+    return __awaiter(this, void 0, void 0, function () { return __generator(function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, thenable];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+} // error
diff --git a/tests/baselines/reference/asyncFunctionDeclaration1_es5.js b/tests/baselines/reference/asyncFunctionDeclaration1_es5.js
new file mode 100644
index 00000000000..3f020ec6ece
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration1_es5.js
@@ -0,0 +1,12 @@
+//// [asyncFunctionDeclaration1_es5.ts]
+async function foo(): Promise<void> {
+}
+
+//// [asyncFunctionDeclaration1_es5.js]
+function foo() {
+    return __awaiter(this, void 0, Promise, function () {
+        return __generator(function (_a) {
+            return [2 /*return*/];
+        });
+    });
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration1_es5.symbols b/tests/baselines/reference/asyncFunctionDeclaration1_es5.symbols
new file mode 100644
index 00000000000..ba7616ac293
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration1_es5.symbols
@@ -0,0 +1,5 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration1_es5.ts ===
+async function foo(): Promise<void> {
+>foo : Symbol(foo, Decl(asyncFunctionDeclaration1_es5.ts, 0, 0))
+>Promise : Symbol(Promise, Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --))
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration1_es5.types b/tests/baselines/reference/asyncFunctionDeclaration1_es5.types
new file mode 100644
index 00000000000..b1336715bfb
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration1_es5.types
@@ -0,0 +1,5 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration1_es5.ts ===
+async function foo(): Promise<void> {
+>foo : () => Promise<void>
+>Promise : Promise<T>
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration2_es5.js b/tests/baselines/reference/asyncFunctionDeclaration2_es5.js
new file mode 100644
index 00000000000..427fb2b1bf9
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration2_es5.js
@@ -0,0 +1,7 @@
+//// [asyncFunctionDeclaration2_es5.ts]
+function f(await) {
+}
+
+//// [asyncFunctionDeclaration2_es5.js]
+function f(await) {
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration2_es5.symbols b/tests/baselines/reference/asyncFunctionDeclaration2_es5.symbols
new file mode 100644
index 00000000000..78f4da3c25e
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration2_es5.symbols
@@ -0,0 +1,5 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration2_es5.ts ===
+function f(await) {
+>f : Symbol(f, Decl(asyncFunctionDeclaration2_es5.ts, 0, 0))
+>await : Symbol(await, Decl(asyncFunctionDeclaration2_es5.ts, 0, 11))
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration2_es5.types b/tests/baselines/reference/asyncFunctionDeclaration2_es5.types
new file mode 100644
index 00000000000..7add17dd5d6
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration2_es5.types
@@ -0,0 +1,5 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration2_es5.ts ===
+function f(await) {
+>f : (await: any) => void
+>await : any
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration3_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration3_es5.errors.txt
new file mode 100644
index 00000000000..1192e396a64
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration3_es5.errors.txt
@@ -0,0 +1,8 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration3_es5.ts(1,20): error TS2372: Parameter 'await' cannot be referenced in its initializer.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration3_es5.ts (1 errors) ====
+    function f(await = await) {
+                       ~~~~~
+!!! error TS2372: Parameter 'await' cannot be referenced in its initializer.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration3_es5.js b/tests/baselines/reference/asyncFunctionDeclaration3_es5.js
new file mode 100644
index 00000000000..0bcc99b6bc7
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration3_es5.js
@@ -0,0 +1,8 @@
+//// [asyncFunctionDeclaration3_es5.ts]
+function f(await = await) {
+}
+
+//// [asyncFunctionDeclaration3_es5.js]
+function f(await) {
+    if (await === void 0) { await = await; }
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration4_es5.js b/tests/baselines/reference/asyncFunctionDeclaration4_es5.js
new file mode 100644
index 00000000000..8b6f58b84ab
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration4_es5.js
@@ -0,0 +1,7 @@
+//// [asyncFunctionDeclaration4_es5.ts]
+function await() {
+}
+
+//// [asyncFunctionDeclaration4_es5.js]
+function await() {
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration4_es5.symbols b/tests/baselines/reference/asyncFunctionDeclaration4_es5.symbols
new file mode 100644
index 00000000000..0690c333095
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration4_es5.symbols
@@ -0,0 +1,4 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration4_es5.ts ===
+function await() {
+>await : Symbol(await, Decl(asyncFunctionDeclaration4_es5.ts, 0, 0))
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration4_es5.types b/tests/baselines/reference/asyncFunctionDeclaration4_es5.types
new file mode 100644
index 00000000000..8dac2282032
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration4_es5.types
@@ -0,0 +1,4 @@
+=== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration4_es5.ts ===
+function await() {
+>await : () => void
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration5_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration5_es5.errors.txt
new file mode 100644
index 00000000000..3060c2c836b
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration5_es5.errors.txt
@@ -0,0 +1,20 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts(1,20): error TS1138: Parameter declaration expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts(1,20): error TS2304: Cannot find name 'await'.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts(1,25): error TS1005: ';' expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts(1,26): error TS1128: Declaration or statement expected.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts(1,40): error TS1109: Expression expected.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts (5 errors) ====
+    async function foo(await): Promise<void> {
+                       ~~~~~
+!!! error TS1138: Parameter declaration expected.
+                       ~~~~~
+!!! error TS2304: Cannot find name 'await'.
+                            ~
+!!! error TS1005: ';' expected.
+                             ~
+!!! error TS1128: Declaration or statement expected.
+                                           ~
+!!! error TS1109: Expression expected.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration5_es5.js b/tests/baselines/reference/asyncFunctionDeclaration5_es5.js
new file mode 100644
index 00000000000..22c18ff6ad4
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration5_es5.js
@@ -0,0 +1,7 @@
+//// [asyncFunctionDeclaration5_es5.ts]
+async function foo(await): Promise<void> {
+}
+
+//// [asyncFunctionDeclaration5_es5.js]
+await;
+Promise < void  > {};
diff --git a/tests/baselines/reference/asyncFunctionDeclaration6_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration6_es5.errors.txt
new file mode 100644
index 00000000000..d8cf82fbc28
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration6_es5.errors.txt
@@ -0,0 +1,11 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration6_es5.ts(1,24): error TS2524: 'await' expressions cannot be used in a parameter initializer.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration6_es5.ts(1,29): error TS1109: Expression expected.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration6_es5.ts (2 errors) ====
+    async function foo(a = await): Promise<void> {
+                           ~~~~~
+!!! error TS2524: 'await' expressions cannot be used in a parameter initializer.
+                                ~
+!!! error TS1109: Expression expected.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration6_es5.js b/tests/baselines/reference/asyncFunctionDeclaration6_es5.js
new file mode 100644
index 00000000000..2ee26f29e62
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration6_es5.js
@@ -0,0 +1,13 @@
+//// [asyncFunctionDeclaration6_es5.ts]
+async function foo(a = await): Promise<void> {
+}
+
+//// [asyncFunctionDeclaration6_es5.js]
+function foo(a) {
+    if (a === void 0) { a = yield ; }
+    return __awaiter(this, void 0, Promise, function () {
+        return __generator(function (_a) {
+            return [2 /*return*/];
+        });
+    });
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration7_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration7_es5.errors.txt
new file mode 100644
index 00000000000..48984724e4c
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration7_es5.errors.txt
@@ -0,0 +1,14 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration7_es5.ts(3,26): error TS2524: 'await' expressions cannot be used in a parameter initializer.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration7_es5.ts(3,31): error TS1109: Expression expected.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration7_es5.ts (2 errors) ====
+    async function bar(): Promise<void> {
+      // 'await' here is an identifier, and not a yield expression.
+      async function foo(a = await): Promise<void> {
+                             ~~~~~
+!!! error TS2524: 'await' expressions cannot be used in a parameter initializer.
+                                  ~
+!!! error TS1109: Expression expected.
+      }
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration7_es5.js b/tests/baselines/reference/asyncFunctionDeclaration7_es5.js
new file mode 100644
index 00000000000..7bcf3be59ad
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration7_es5.js
@@ -0,0 +1,24 @@
+//// [asyncFunctionDeclaration7_es5.ts]
+async function bar(): Promise<void> {
+  // 'await' here is an identifier, and not a yield expression.
+  async function foo(a = await): Promise<void> {
+  }
+}
+
+//// [asyncFunctionDeclaration7_es5.js]
+function bar() {
+    return __awaiter(this, void 0, Promise, function () {
+        // 'await' here is an identifier, and not a yield expression.
+        function foo(a) {
+            if (a === void 0) { a = yield ; }
+            return __awaiter(this, void 0, Promise, function () {
+                return __generator(function (_a) {
+                    return [2 /*return*/];
+                });
+            });
+        }
+        return __generator(function (_a) {
+            return [2 /*return*/];
+        });
+    });
+}
diff --git a/tests/baselines/reference/asyncFunctionDeclaration8_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration8_es5.errors.txt
new file mode 100644
index 00000000000..7f2a4cc650b
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration8_es5.errors.txt
@@ -0,0 +1,10 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration8_es5.ts(1,12): error TS2304: Cannot find name 'await'.
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration8_es5.ts(1,20): error TS2304: Cannot find name 'foo'.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration8_es5.ts (2 errors) ====
+    var v = { [await]: foo }
+               ~~~~~
+!!! error TS2304: Cannot find name 'await'.
+                       ~~~
+!!! error TS2304: Cannot find name 'foo'.
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration8_es5.js b/tests/baselines/reference/asyncFunctionDeclaration8_es5.js
new file mode 100644
index 00000000000..3e518481178
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration8_es5.js
@@ -0,0 +1,6 @@
+//// [asyncFunctionDeclaration8_es5.ts]
+var v = { [await]: foo }
+
+//// [asyncFunctionDeclaration8_es5.js]
+var v = (_a = {}, _a[await] = foo, _a);
+var _a;
diff --git a/tests/baselines/reference/asyncFunctionDeclaration9_es5.errors.txt b/tests/baselines/reference/asyncFunctionDeclaration9_es5.errors.txt
new file mode 100644
index 00000000000..8eed8dade45
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration9_es5.errors.txt
@@ -0,0 +1,9 @@
+tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration9_es5.ts(2,19): error TS1109: Expression expected.
+
+
+==== tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration9_es5.ts (1 errors) ====
+    async function foo(): Promise<void> {
+      var v = { [await]: foo }
+                      ~
+!!! error TS1109: Expression expected.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/asyncFunctionDeclaration9_es5.js b/tests/baselines/reference/asyncFunctionDeclaration9_es5.js
new file mode 100644
index 00000000000..2da28f95cff
--- /dev/null
+++ b/tests/baselines/reference/asyncFunctionDeclaration9_es5.js
@@ -0,0 +1,21 @@
+//// [asyncFunctionDeclaration9_es5.ts]
+async function foo(): Promise<void> {
+  var v = { [await]: foo }
+}
+
+//// [asyncFunctionDeclaration9_es5.js]
+function foo() {
+    return __awaiter(this, void 0, Promise, function () {
+        var v, _a;
+        return __generator(function (_b) {
+            switch (_b.label) {
+                case 0:
+                    _a = {};
+                    return [4 /*yield*/, ];
+                case 1:
+                    v = (_a[_b.sent()] = foo, _a);
+                    return [2 /*return*/];
+            }
+        });
+    });
+}
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts
new file mode 100644
index 00000000000..f1cb80162bd
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration10_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function foo(a = await => await): Promise<void> {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration11_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration11_es5.ts
new file mode 100644
index 00000000000..8edf36f9a2f
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration11_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function await(): Promise<void> {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts
new file mode 100644
index 00000000000..4601fba6ea2
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration12_es5.ts
@@ -0,0 +1,4 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+var v = async function await(): Promise<void> { }
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration13_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration13_es5.ts
new file mode 100644
index 00000000000..2b70bc4c641
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration13_es5.ts
@@ -0,0 +1,7 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function foo(): Promise<void> {
+   // Legal to use 'await' in a type context.
+   var v: await;
+}
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration14_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration14_es5.ts
new file mode 100644
index 00000000000..eedfd438b7c
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration14_es5.ts
@@ -0,0 +1,6 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function foo(): Promise<void> {
+  return;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts
new file mode 100644
index 00000000000..373677bf58f
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration15_es5.ts
@@ -0,0 +1,26 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+declare class Thenable { then(): void; }
+declare let a: any;
+declare let obj: { then: string; };
+declare let thenable: Thenable;
+async function fn1() { } // valid: Promise<void>
+async function fn2(): { } { } // error
+async function fn3(): any { } // error
+async function fn4(): number { } // error
+async function fn5(): PromiseLike<void> { } // error
+async function fn6(): Thenable { } // error
+async function fn7() { return; } // valid: Promise<void>
+async function fn8() { return 1; } // valid: Promise<number>
+async function fn9() { return null; } // valid: Promise<any>
+async function fn10() { return undefined; } // valid: Promise<any>
+async function fn11() { return a; } // valid: Promise<any>
+async function fn12() { return obj; } // valid: Promise<{ then: string; }>
+async function fn13() { return thenable; } // error
+async function fn14() { await 1; } // valid: Promise<void>
+async function fn15() { await null; } // valid: Promise<void>
+async function fn16() { await undefined; } // valid: Promise<void>
+async function fn17() { await a; } // valid: Promise<void>
+async function fn18() { await obj; } // valid: Promise<void>
+async function fn19() { await thenable; } // error
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration1_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration1_es5.ts
new file mode 100644
index 00000000000..1448b335992
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration1_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function foo(): Promise<void> {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration2_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration2_es5.ts
new file mode 100644
index 00000000000..b1e337938e0
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration2_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+function f(await) {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration3_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration3_es5.ts
new file mode 100644
index 00000000000..810d7bc7e05
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration3_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+function f(await = await) {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration4_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration4_es5.ts
new file mode 100644
index 00000000000..40bd69d592f
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration4_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+function await() {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts
new file mode 100644
index 00000000000..3c71741da14
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration5_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function foo(await): Promise<void> {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration6_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration6_es5.ts
new file mode 100644
index 00000000000..34ff3b3c4c5
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration6_es5.ts
@@ -0,0 +1,5 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function foo(a = await): Promise<void> {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration7_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration7_es5.ts
new file mode 100644
index 00000000000..53d7bc5edb5
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration7_es5.ts
@@ -0,0 +1,8 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function bar(): Promise<void> {
+  // 'await' here is an identifier, and not a yield expression.
+  async function foo(a = await): Promise<void> {
+  }
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration8_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration8_es5.ts
new file mode 100644
index 00000000000..27db170b080
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration8_es5.ts
@@ -0,0 +1,4 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+var v = { [await]: foo }
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration9_es5.ts b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration9_es5.ts
new file mode 100644
index 00000000000..7a1130f8abf
--- /dev/null
+++ b/tests/cases/conformance/async/es5/functionDeclarations/asyncFunctionDeclaration9_es5.ts
@@ -0,0 +1,6 @@
+// @target: ES5
+// @lib: es5,es2015.promise
+// @noEmitHelpers: true
+async function foo(): Promise<void> {
+  var v = { [await]: foo }
+}
\ No newline at end of file