From 8f6ad87d9980d028b312924c9bca1ff92ddb02a8 Mon Sep 17 00:00:00 2001
From: Zzzen <callmetsing@gmail.com>
Date: Tue, 13 Jul 2021 19:01:12 +0800
Subject: [PATCH] support contextual return type of iife

---
 src/compiler/checker.ts                       |  4 ++
 .../reference/contextualReturnTypeOfIIFE.js   | 61 +++++++++++++++++++
 .../contextualReturnTypeOfIIFE.symbols        | 28 +++++++++
 .../contextualReturnTypeOfIIFE.types          | 46 ++++++++++++++
 .../reference/generatorTypeCheck27.symbols    |  2 +
 .../reference/generatorTypeCheck27.types      | 16 ++---
 .../reference/generatorTypeCheck29.symbols    |  2 +
 .../reference/generatorTypeCheck29.types      | 16 ++---
 .../reference/generatorTypeCheck30.symbols    |  2 +
 .../reference/generatorTypeCheck30.types      | 16 ++---
 .../reference/generatorTypeCheck31.errors.txt |  8 +--
 .../reference/generatorTypeCheck31.types      |  4 +-
 .../types.asyncGenerators.es2018.1.types      | 54 ++++++++--------
 .../types.asyncGenerators.es2018.2.errors.txt | 32 ++++------
 .../types.asyncGenerators.es2018.2.types      | 54 ++++++++--------
 .../compiler/contextualReturnTypeOfIIFE.ts    | 13 ++++
 16 files changed, 254 insertions(+), 104 deletions(-)
 create mode 100644 tests/baselines/reference/contextualReturnTypeOfIIFE.js
 create mode 100644 tests/baselines/reference/contextualReturnTypeOfIIFE.symbols
 create mode 100644 tests/baselines/reference/contextualReturnTypeOfIIFE.types
 create mode 100644 tests/cases/compiler/contextualReturnTypeOfIIFE.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index f5f458a560573..bfe68f7c703a7 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -25309,6 +25309,10 @@ namespace ts {
             if (signature && !isResolvingReturnTypeOfSignature(signature)) {
                 return getReturnTypeOfSignature(signature);
             }
+            const iife = getImmediatelyInvokedFunctionExpression(functionDecl);
+            if (iife) {
+                return getContextualType(iife);
+            }
             return undefined;
         }
 
diff --git a/tests/baselines/reference/contextualReturnTypeOfIIFE.js b/tests/baselines/reference/contextualReturnTypeOfIIFE.js
new file mode 100644
index 0000000000000..a742ee232fb3a
--- /dev/null
+++ b/tests/baselines/reference/contextualReturnTypeOfIIFE.js
@@ -0,0 +1,61 @@
+//// [contextualReturnTypeOfIIFE.ts]
+const test1: Promise<[one: number, two: string]> = (async () => {
+    return [1, 'two'];
+})();
+
+const test2: Promise<[one: number, two: string]> = new Promise(
+    (resolve) => resolve([1, 'two']),
+);
+
+const obj: { foo: [one: number, two: string] } = {
+    foo: (() => [1, 'two'])()
+};
+
+
+//// [contextualReturnTypeOfIIFE.js]
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
+    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) : adopt(result.value).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+var __generator = (this && this.__generator) || function (thisArg, body) {
+    var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
+    return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
+    function verb(n) { return function (v) { return step([n, v]); }; }
+    function step(op) {
+        if (f) throw new TypeError("Generator is already executing.");
+        while (_) try {
+            if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
+            if (y = 0, t) op = [op[0] & 2, t.value];
+            switch (op[0]) {
+                case 0: case 1: t = op; break;
+                case 4: _.label++; return { value: op[1], done: false };
+                case 5: _.label++; y = op[1]; op = [0]; continue;
+                case 7: op = _.ops.pop(); _.trys.pop(); continue;
+                default:
+                    if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
+                    if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
+                    if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
+                    if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
+                    if (t[2]) _.ops.pop();
+                    _.trys.pop(); continue;
+            }
+            op = body.call(thisArg, _);
+        } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
+        if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
+    }
+};
+var _this = this;
+var test1 = (function () { return __awaiter(_this, void 0, void 0, function () {
+    return __generator(this, function (_a) {
+        return [2 /*return*/, [1, 'two']];
+    });
+}); })();
+var test2 = new Promise(function (resolve) { return resolve([1, 'two']); });
+var obj = {
+    foo: (function () { return [1, 'two']; })()
+};
diff --git a/tests/baselines/reference/contextualReturnTypeOfIIFE.symbols b/tests/baselines/reference/contextualReturnTypeOfIIFE.symbols
new file mode 100644
index 0000000000000..2602cae384c0a
--- /dev/null
+++ b/tests/baselines/reference/contextualReturnTypeOfIIFE.symbols
@@ -0,0 +1,28 @@
+=== tests/cases/compiler/contextualReturnTypeOfIIFE.ts ===
+const test1: Promise<[one: number, two: string]> = (async () => {
+>test1 : Symbol(test1, Decl(contextualReturnTypeOfIIFE.ts, 0, 5))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+
+    return [1, 'two'];
+})();
+
+const test2: Promise<[one: number, two: string]> = new Promise(
+>test2 : Symbol(test2, Decl(contextualReturnTypeOfIIFE.ts, 4, 5))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+
+    (resolve) => resolve([1, 'two']),
+>resolve : Symbol(resolve, Decl(contextualReturnTypeOfIIFE.ts, 5, 5))
+>resolve : Symbol(resolve, Decl(contextualReturnTypeOfIIFE.ts, 5, 5))
+
+);
+
+const obj: { foo: [one: number, two: string] } = {
+>obj : Symbol(obj, Decl(contextualReturnTypeOfIIFE.ts, 8, 5))
+>foo : Symbol(foo, Decl(contextualReturnTypeOfIIFE.ts, 8, 12))
+
+    foo: (() => [1, 'two'])()
+>foo : Symbol(foo, Decl(contextualReturnTypeOfIIFE.ts, 8, 50))
+
+};
+
diff --git a/tests/baselines/reference/contextualReturnTypeOfIIFE.types b/tests/baselines/reference/contextualReturnTypeOfIIFE.types
new file mode 100644
index 0000000000000..b5289ca2c7640
--- /dev/null
+++ b/tests/baselines/reference/contextualReturnTypeOfIIFE.types
@@ -0,0 +1,46 @@
+=== tests/cases/compiler/contextualReturnTypeOfIIFE.ts ===
+const test1: Promise<[one: number, two: string]> = (async () => {
+>test1 : Promise<[one: number, two: string]>
+>(async () => {    return [1, 'two'];})() : Promise<[number, string]>
+>(async () => {    return [1, 'two'];}) : () => Promise<[number, string]>
+>async () => {    return [1, 'two'];} : () => Promise<[number, string]>
+
+    return [1, 'two'];
+>[1, 'two'] : [number, string]
+>1 : 1
+>'two' : "two"
+
+})();
+
+const test2: Promise<[one: number, two: string]> = new Promise(
+>test2 : Promise<[one: number, two: string]>
+>new Promise(    (resolve) => resolve([1, 'two']),) : Promise<[one: number, two: string]>
+>Promise : PromiseConstructor
+
+    (resolve) => resolve([1, 'two']),
+>(resolve) => resolve([1, 'two']) : (resolve: (value: [one: number, two: string] | PromiseLike<[one: number, two: string]>) => void) => void
+>resolve : (value: [one: number, two: string] | PromiseLike<[one: number, two: string]>) => void
+>resolve([1, 'two']) : void
+>resolve : (value: [one: number, two: string] | PromiseLike<[one: number, two: string]>) => void
+>[1, 'two'] : [number, string]
+>1 : 1
+>'two' : "two"
+
+);
+
+const obj: { foo: [one: number, two: string] } = {
+>obj : { foo: [one: number, two: string]; }
+>foo : [one: number, two: string]
+>{    foo: (() => [1, 'two'])()} : { foo: [number, string]; }
+
+    foo: (() => [1, 'two'])()
+>foo : [number, string]
+>(() => [1, 'two'])() : [number, string]
+>(() => [1, 'two']) : () => [number, string]
+>() => [1, 'two'] : () => [number, string]
+>[1, 'two'] : [number, string]
+>1 : 1
+>'two' : "two"
+
+};
+
diff --git a/tests/baselines/reference/generatorTypeCheck27.symbols b/tests/baselines/reference/generatorTypeCheck27.symbols
index 58f5e56242385..1feb7aed7e4f0 100644
--- a/tests/baselines/reference/generatorTypeCheck27.symbols
+++ b/tests/baselines/reference/generatorTypeCheck27.symbols
@@ -7,7 +7,9 @@ function* g(): IterableIterator<(x: string) => number> {
     yield * function* () {
         yield x => x.length;
 >x : Symbol(x, Decl(generatorTypeCheck27.ts, 2, 13))
+>x.length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
 >x : Symbol(x, Decl(generatorTypeCheck27.ts, 2, 13))
+>length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
 
     } ();
 }
diff --git a/tests/baselines/reference/generatorTypeCheck27.types b/tests/baselines/reference/generatorTypeCheck27.types
index 58306e1fb4aec..35bf7edc864ff 100644
--- a/tests/baselines/reference/generatorTypeCheck27.types
+++ b/tests/baselines/reference/generatorTypeCheck27.types
@@ -5,16 +5,16 @@ function* g(): IterableIterator<(x: string) => number> {
 
     yield * function* () {
 >yield * function* () {        yield x => x.length;    } () : void
->function* () {        yield x => x.length;    } () : Generator<(x: any) => any, void, unknown>
->function* () {        yield x => x.length;    } : () => Generator<(x: any) => any, void, unknown>
+>function* () {        yield x => x.length;    } () : Generator<(x: string) => number, void, undefined>
+>function* () {        yield x => x.length;    } : () => Generator<(x: string) => number, void, undefined>
 
         yield x => x.length;
->yield x => x.length : any
->x => x.length : (x: any) => any
->x : any
->x.length : any
->x : any
->length : any
+>yield x => x.length : undefined
+>x => x.length : (x: string) => number
+>x : string
+>x.length : number
+>x : string
+>length : number
 
     } ();
 }
diff --git a/tests/baselines/reference/generatorTypeCheck29.symbols b/tests/baselines/reference/generatorTypeCheck29.symbols
index 5ea31ccb0cd67..e4c1b8850c557 100644
--- a/tests/baselines/reference/generatorTypeCheck29.symbols
+++ b/tests/baselines/reference/generatorTypeCheck29.symbols
@@ -8,7 +8,9 @@ function* g2(): Iterator<Iterable<(x: string) => number>> {
     yield function* () {
         yield x => x.length;
 >x : Symbol(x, Decl(generatorTypeCheck29.ts, 2, 13))
+>x.length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
 >x : Symbol(x, Decl(generatorTypeCheck29.ts, 2, 13))
+>length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
 
     } ()
 }
diff --git a/tests/baselines/reference/generatorTypeCheck29.types b/tests/baselines/reference/generatorTypeCheck29.types
index 0ce49791a22c6..71d781eaa4d07 100644
--- a/tests/baselines/reference/generatorTypeCheck29.types
+++ b/tests/baselines/reference/generatorTypeCheck29.types
@@ -5,16 +5,16 @@ function* g2(): Iterator<Iterable<(x: string) => number>> {
 
     yield function* () {
 >yield function* () {        yield x => x.length;    } () : undefined
->function* () {        yield x => x.length;    } () : Generator<(x: any) => any, void, unknown>
->function* () {        yield x => x.length;    } : () => Generator<(x: any) => any, void, unknown>
+>function* () {        yield x => x.length;    } () : Generator<(x: string) => number, void, undefined>
+>function* () {        yield x => x.length;    } : () => Generator<(x: string) => number, void, undefined>
 
         yield x => x.length;
->yield x => x.length : any
->x => x.length : (x: any) => any
->x : any
->x.length : any
->x : any
->length : any
+>yield x => x.length : undefined
+>x => x.length : (x: string) => number
+>x : string
+>x.length : number
+>x : string
+>length : number
 
     } ()
 }
diff --git a/tests/baselines/reference/generatorTypeCheck30.symbols b/tests/baselines/reference/generatorTypeCheck30.symbols
index f1626cf067f86..d7d346db0adb3 100644
--- a/tests/baselines/reference/generatorTypeCheck30.symbols
+++ b/tests/baselines/reference/generatorTypeCheck30.symbols
@@ -8,7 +8,9 @@ function* g2(): Iterator<Iterable<(x: string) => number>> {
     yield function* () {
         yield x => x.length;
 >x : Symbol(x, Decl(generatorTypeCheck30.ts, 2, 13))
+>x.length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
 >x : Symbol(x, Decl(generatorTypeCheck30.ts, 2, 13))
+>length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
 
     } ()
 }
diff --git a/tests/baselines/reference/generatorTypeCheck30.types b/tests/baselines/reference/generatorTypeCheck30.types
index 094ed3bf33758..12f06dc09dfb2 100644
--- a/tests/baselines/reference/generatorTypeCheck30.types
+++ b/tests/baselines/reference/generatorTypeCheck30.types
@@ -5,16 +5,16 @@ function* g2(): Iterator<Iterable<(x: string) => number>> {
 
     yield function* () {
 >yield function* () {        yield x => x.length;    } () : undefined
->function* () {        yield x => x.length;    } () : Generator<(x: any) => any, void, unknown>
->function* () {        yield x => x.length;    } : () => Generator<(x: any) => any, void, unknown>
+>function* () {        yield x => x.length;    } () : Generator<(x: string) => number, void, undefined>
+>function* () {        yield x => x.length;    } : () => Generator<(x: string) => number, void, undefined>
 
         yield x => x.length;
->yield x => x.length : any
->x => x.length : (x: any) => any
->x : any
->x.length : any
->x : any
->length : any
+>yield x => x.length : undefined
+>x => x.length : (x: string) => number
+>x : string
+>x.length : number
+>x : string
+>length : number
 
     } ()
 }
diff --git a/tests/baselines/reference/generatorTypeCheck31.errors.txt b/tests/baselines/reference/generatorTypeCheck31.errors.txt
index 0ed5dcbe0e08f..9aaf3b745ee4e 100644
--- a/tests/baselines/reference/generatorTypeCheck31.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck31.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck31.ts(2,11): error TS2322: Type 'Generator<(x: any) => any, void, unknown>' is not assignable to type '() => Iterable<(x: string) => number>'.
-  Type 'Generator<(x: any) => any, void, unknown>' provides no match for the signature '(): Iterable<(x: string) => number>'.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck31.ts(2,11): error TS2322: Type 'Generator<(x: any) => any, void, any>' is not assignable to type '() => Iterable<(x: string) => number>'.
+  Type 'Generator<(x: any) => any, void, any>' provides no match for the signature '(): Iterable<(x: string) => number>'.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck31.ts (1 errors) ====
@@ -10,6 +10,6 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck31.ts(2,11): erro
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         } ()
     ~~~~~~~~
-!!! error TS2322: Type 'Generator<(x: any) => any, void, unknown>' is not assignable to type '() => Iterable<(x: string) => number>'.
-!!! error TS2322:   Type 'Generator<(x: any) => any, void, unknown>' provides no match for the signature '(): Iterable<(x: string) => number>'.
+!!! error TS2322: Type 'Generator<(x: any) => any, void, any>' is not assignable to type '() => Iterable<(x: string) => number>'.
+!!! error TS2322:   Type 'Generator<(x: any) => any, void, any>' provides no match for the signature '(): Iterable<(x: string) => number>'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/generatorTypeCheck31.types b/tests/baselines/reference/generatorTypeCheck31.types
index c15eab96fe9e0..2a3828322fffb 100644
--- a/tests/baselines/reference/generatorTypeCheck31.types
+++ b/tests/baselines/reference/generatorTypeCheck31.types
@@ -5,8 +5,8 @@ function* g2(): Iterator<() => Iterable<(x: string) => number>> {
 
     yield function* () {
 >yield function* () {        yield x => x.length;    } () : undefined
->function* () {        yield x => x.length;    } () : Generator<(x: any) => any, void, unknown>
->function* () {        yield x => x.length;    } : () => Generator<(x: any) => any, void, unknown>
+>function* () {        yield x => x.length;    } () : Generator<(x: any) => any, void, any>
+>function* () {        yield x => x.length;    } : () => Generator<(x: any) => any, void, any>
 
         yield x => x.length;
 >yield x => x.length : any
diff --git a/tests/baselines/reference/types.asyncGenerators.es2018.1.types b/tests/baselines/reference/types.asyncGenerators.es2018.1.types
index e0c769a74d67b..10f961da0a2bf 100644
--- a/tests/baselines/reference/types.asyncGenerators.es2018.1.types
+++ b/tests/baselines/reference/types.asyncGenerators.es2018.1.types
@@ -122,14 +122,14 @@ const assignability4: () => AsyncIterableIterator<number> = async function * ()
 };
 const assignability5: () => AsyncIterableIterator<number> = async function * () {
 >assignability5 : () => AsyncIterableIterator<number>
->async function * () {    yield* (async function * () { yield 1; })();} : () => AsyncGenerator<number, void, unknown>
+>async function * () {    yield* (async function * () { yield 1; })();} : () => AsyncGenerator<number, void, undefined>
 
     yield* (async function * () { yield 1; })();
 >yield* (async function * () { yield 1; })() : void
->(async function * () { yield 1; })() : AsyncGenerator<number, void, unknown>
->(async function * () { yield 1; }) : () => AsyncGenerator<number, void, unknown>
->async function * () { yield 1; } : () => AsyncGenerator<number, void, unknown>
->yield 1 : any
+>(async function * () { yield 1; })() : AsyncGenerator<number, void, undefined>
+>(async function * () { yield 1; }) : () => AsyncGenerator<number, void, undefined>
+>async function * () { yield 1; } : () => AsyncGenerator<number, void, undefined>
+>yield 1 : undefined
 >1 : 1
 
 };
@@ -182,14 +182,14 @@ const assignability9: () => AsyncIterable<number> = async function * () {
 };
 const assignability10: () => AsyncIterable<number> = async function * () {
 >assignability10 : () => AsyncIterable<number>
->async function * () {    yield* (async function * () { yield 1; })();} : () => AsyncGenerator<number, void, unknown>
+>async function * () {    yield* (async function * () { yield 1; })();} : () => AsyncGenerator<number, void, undefined>
 
     yield* (async function * () { yield 1; })();
 >yield* (async function * () { yield 1; })() : void
->(async function * () { yield 1; })() : AsyncGenerator<number, void, unknown>
->(async function * () { yield 1; }) : () => AsyncGenerator<number, void, unknown>
->async function * () { yield 1; } : () => AsyncGenerator<number, void, unknown>
->yield 1 : any
+>(async function * () { yield 1; })() : AsyncGenerator<number, void, undefined>
+>(async function * () { yield 1; }) : () => AsyncGenerator<number, void, undefined>
+>async function * () { yield 1; } : () => AsyncGenerator<number, void, undefined>
+>yield 1 : undefined
 >1 : 1
 
 };
@@ -242,14 +242,14 @@ const assignability14: () => AsyncIterator<number> = async function * () {
 };
 const assignability15: () => AsyncIterator<number> = async function * () {
 >assignability15 : () => AsyncIterator<number>
->async function * () {    yield* (async function * () { yield 1; })();} : () => AsyncGenerator<number, void, unknown>
+>async function * () {    yield* (async function * () { yield 1; })();} : () => AsyncGenerator<number, void, undefined>
 
     yield* (async function * () { yield 1; })();
 >yield* (async function * () { yield 1; })() : void
->(async function * () { yield 1; })() : AsyncGenerator<number, void, unknown>
->(async function * () { yield 1; }) : () => AsyncGenerator<number, void, unknown>
->async function * () { yield 1; } : () => AsyncGenerator<number, void, unknown>
->yield 1 : any
+>(async function * () { yield 1; })() : AsyncGenerator<number, void, undefined>
+>(async function * () { yield 1; }) : () => AsyncGenerator<number, void, undefined>
+>async function * () { yield 1; } : () => AsyncGenerator<number, void, undefined>
+>yield 1 : undefined
 >1 : 1
 
 };
@@ -297,10 +297,10 @@ async function * explicitReturnType5(): AsyncIterableIterator<number> {
 
     yield* (async function * () { yield 1; })();
 >yield* (async function * () { yield 1; })() : void
->(async function * () { yield 1; })() : AsyncGenerator<number, void, unknown>
->(async function * () { yield 1; }) : () => AsyncGenerator<number, void, unknown>
->async function * () { yield 1; } : () => AsyncGenerator<number, void, unknown>
->yield 1 : any
+>(async function * () { yield 1; })() : AsyncGenerator<number, void, undefined>
+>(async function * () { yield 1; }) : () => AsyncGenerator<number, void, undefined>
+>async function * () { yield 1; } : () => AsyncGenerator<number, void, undefined>
+>yield 1 : undefined
 >1 : 1
 }
 async function * explicitReturnType6(): AsyncIterable<number> {
@@ -347,10 +347,10 @@ async function * explicitReturnType10(): AsyncIterable<number> {
 
     yield* (async function * () { yield 1; })();
 >yield* (async function * () { yield 1; })() : void
->(async function * () { yield 1; })() : AsyncGenerator<number, void, unknown>
->(async function * () { yield 1; }) : () => AsyncGenerator<number, void, unknown>
->async function * () { yield 1; } : () => AsyncGenerator<number, void, unknown>
->yield 1 : any
+>(async function * () { yield 1; })() : AsyncGenerator<number, void, undefined>
+>(async function * () { yield 1; }) : () => AsyncGenerator<number, void, undefined>
+>async function * () { yield 1; } : () => AsyncGenerator<number, void, undefined>
+>yield 1 : undefined
 >1 : 1
 }
 async function * explicitReturnType11(): AsyncIterator<number> {
@@ -397,10 +397,10 @@ async function * explicitReturnType15(): AsyncIterator<number> {
 
     yield* (async function * () { yield 1; })();
 >yield* (async function * () { yield 1; })() : void
->(async function * () { yield 1; })() : AsyncGenerator<number, void, unknown>
->(async function * () { yield 1; }) : () => AsyncGenerator<number, void, unknown>
->async function * () { yield 1; } : () => AsyncGenerator<number, void, unknown>
->yield 1 : any
+>(async function * () { yield 1; })() : AsyncGenerator<number, void, undefined>
+>(async function * () { yield 1; }) : () => AsyncGenerator<number, void, undefined>
+>async function * () { yield 1; } : () => AsyncGenerator<number, void, undefined>
+>yield 1 : undefined
 >1 : 1
 }
 async function * explicitReturnType16(): {} {
diff --git a/tests/baselines/reference/types.asyncGenerators.es2018.2.errors.txt b/tests/baselines/reference/types.asyncGenerators.es2018.2.errors.txt
index 2b96990092f3d..b0f976b703691 100644
--- a/tests/baselines/reference/types.asyncGenerators.es2018.2.errors.txt
+++ b/tests/baselines/reference/types.asyncGenerators.es2018.2.errors.txt
@@ -10,26 +10,22 @@ tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(
               Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(13,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterableIterator<number>'.
   Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterableIterator<number>'.
-tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(16,7): error TS2322: Type '() => AsyncGenerator<string, void, unknown>' is not assignable to type '() => AsyncIterableIterator<number>'.
-  Call signature return types 'AsyncGenerator<string, void, unknown>' and 'AsyncIterableIterator<number>' are incompatible.
-    The types returned by 'next(...)' are incompatible between these types.
-      Type 'Promise<IteratorResult<string, void>>' is not assignable to type 'Promise<IteratorResult<number, any>>'.
+tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(16,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterableIterator<number>'.
+  Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterableIterator<number>'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(19,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterable<number>'.
   Call signature return types 'AsyncGenerator<string, void, undefined>' and 'AsyncIterable<number>' are incompatible.
     The types of '[Symbol.asyncIterator]().next' are incompatible between these types.
       Type '(...args: [] | [undefined]) => Promise<IteratorResult<string, void>>' is not assignable to type '(...args: [] | [undefined]) => Promise<IteratorResult<number, any>>'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(22,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterable<number>'.
   Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterable<number>'.
-tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(25,7): error TS2322: Type '() => AsyncGenerator<string, void, unknown>' is not assignable to type '() => AsyncIterable<number>'.
-  Call signature return types 'AsyncGenerator<string, void, unknown>' and 'AsyncIterable<number>' are incompatible.
-    The types of '[Symbol.asyncIterator]().next' are incompatible between these types.
-      Type '(...args: [] | [unknown]) => Promise<IteratorResult<string, void>>' is not assignable to type '(...args: [] | [undefined]) => Promise<IteratorResult<number, any>>'.
+tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(25,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterable<number>'.
+  Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterable<number>'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(28,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterator<number, any, undefined>'.
   Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterator<number, any, undefined>'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(31,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterator<number, any, undefined>'.
   Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterator<number, any, undefined>'.
-tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(34,7): error TS2322: Type '() => AsyncGenerator<string, void, unknown>' is not assignable to type '() => AsyncIterator<number, any, undefined>'.
-  Type 'AsyncGenerator<string, void, unknown>' is not assignable to type 'AsyncIterator<number, any, undefined>'.
+tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(34,7): error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterator<number, any, undefined>'.
+  Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterator<number, any, undefined>'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(38,11): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(41,12): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(44,12): error TS2322: Type 'string' is not assignable to type 'number'.
@@ -83,10 +79,8 @@ tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(
     };
     const assignability3: () => AsyncIterableIterator<number> = async function * () {
           ~~~~~~~~~~~~~~
-!!! error TS2322: Type '() => AsyncGenerator<string, void, unknown>' is not assignable to type '() => AsyncIterableIterator<number>'.
-!!! error TS2322:   Call signature return types 'AsyncGenerator<string, void, unknown>' and 'AsyncIterableIterator<number>' are incompatible.
-!!! error TS2322:     The types returned by 'next(...)' are incompatible between these types.
-!!! error TS2322:       Type 'Promise<IteratorResult<string, void>>' is not assignable to type 'Promise<IteratorResult<number, any>>'.
+!!! error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterableIterator<number>'.
+!!! error TS2322:   Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterableIterator<number>'.
         yield* (async function * () { yield "a"; })();
     };
     const assignability4: () => AsyncIterable<number> = async function * () {
@@ -105,10 +99,8 @@ tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(
     };
     const assignability6: () => AsyncIterable<number> = async function * () {
           ~~~~~~~~~~~~~~
-!!! error TS2322: Type '() => AsyncGenerator<string, void, unknown>' is not assignable to type '() => AsyncIterable<number>'.
-!!! error TS2322:   Call signature return types 'AsyncGenerator<string, void, unknown>' and 'AsyncIterable<number>' are incompatible.
-!!! error TS2322:     The types of '[Symbol.asyncIterator]().next' are incompatible between these types.
-!!! error TS2322:       Type '(...args: [] | [unknown]) => Promise<IteratorResult<string, void>>' is not assignable to type '(...args: [] | [undefined]) => Promise<IteratorResult<number, any>>'.
+!!! error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterable<number>'.
+!!! error TS2322:   Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterable<number>'.
         yield* (async function * () { yield "a"; })();
     };
     const assignability7: () => AsyncIterator<number> = async function * () {
@@ -125,8 +117,8 @@ tests/cases/conformance/types/asyncGenerators/types.asyncGenerators.es2018.2.ts(
     };
     const assignability9: () => AsyncIterator<number> = async function * () {
           ~~~~~~~~~~~~~~
-!!! error TS2322: Type '() => AsyncGenerator<string, void, unknown>' is not assignable to type '() => AsyncIterator<number, any, undefined>'.
-!!! error TS2322:   Type 'AsyncGenerator<string, void, unknown>' is not assignable to type 'AsyncIterator<number, any, undefined>'.
+!!! error TS2322: Type '() => AsyncGenerator<string, void, undefined>' is not assignable to type '() => AsyncIterator<number, any, undefined>'.
+!!! error TS2322:   Type 'AsyncGenerator<string, void, undefined>' is not assignable to type 'AsyncIterator<number, any, undefined>'.
         yield* (async function * () { yield "a"; })();
     };
     async function * explicitReturnType1(): AsyncIterableIterator<number> {
diff --git a/tests/baselines/reference/types.asyncGenerators.es2018.2.types b/tests/baselines/reference/types.asyncGenerators.es2018.2.types
index 4d52f869d1e8a..15e7936ba6351 100644
--- a/tests/baselines/reference/types.asyncGenerators.es2018.2.types
+++ b/tests/baselines/reference/types.asyncGenerators.es2018.2.types
@@ -49,14 +49,14 @@ const assignability2: () => AsyncIterableIterator<number> = async function * ()
 };
 const assignability3: () => AsyncIterableIterator<number> = async function * () {
 >assignability3 : () => AsyncIterableIterator<number>
->async function * () {    yield* (async function * () { yield "a"; })();} : () => AsyncGenerator<string, void, unknown>
+>async function * () {    yield* (async function * () { yield "a"; })();} : () => AsyncGenerator<string, void, undefined>
 
     yield* (async function * () { yield "a"; })();
 >yield* (async function * () { yield "a"; })() : void
->(async function * () { yield "a"; })() : AsyncGenerator<string, void, unknown>
->(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, unknown>
->async function * () { yield "a"; } : () => AsyncGenerator<string, void, unknown>
->yield "a" : any
+>(async function * () { yield "a"; })() : AsyncGenerator<string, void, undefined>
+>(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, undefined>
+>async function * () { yield "a"; } : () => AsyncGenerator<string, void, undefined>
+>yield "a" : undefined
 >"a" : "a"
 
 };
@@ -82,14 +82,14 @@ const assignability5: () => AsyncIterable<number> = async function * () {
 };
 const assignability6: () => AsyncIterable<number> = async function * () {
 >assignability6 : () => AsyncIterable<number>
->async function * () {    yield* (async function * () { yield "a"; })();} : () => AsyncGenerator<string, void, unknown>
+>async function * () {    yield* (async function * () { yield "a"; })();} : () => AsyncGenerator<string, void, undefined>
 
     yield* (async function * () { yield "a"; })();
 >yield* (async function * () { yield "a"; })() : void
->(async function * () { yield "a"; })() : AsyncGenerator<string, void, unknown>
->(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, unknown>
->async function * () { yield "a"; } : () => AsyncGenerator<string, void, unknown>
->yield "a" : any
+>(async function * () { yield "a"; })() : AsyncGenerator<string, void, undefined>
+>(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, undefined>
+>async function * () { yield "a"; } : () => AsyncGenerator<string, void, undefined>
+>yield "a" : undefined
 >"a" : "a"
 
 };
@@ -115,14 +115,14 @@ const assignability8: () => AsyncIterator<number> = async function * () {
 };
 const assignability9: () => AsyncIterator<number> = async function * () {
 >assignability9 : () => AsyncIterator<number>
->async function * () {    yield* (async function * () { yield "a"; })();} : () => AsyncGenerator<string, void, unknown>
+>async function * () {    yield* (async function * () { yield "a"; })();} : () => AsyncGenerator<string, void, undefined>
 
     yield* (async function * () { yield "a"; })();
 >yield* (async function * () { yield "a"; })() : void
->(async function * () { yield "a"; })() : AsyncGenerator<string, void, unknown>
->(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, unknown>
->async function * () { yield "a"; } : () => AsyncGenerator<string, void, unknown>
->yield "a" : any
+>(async function * () { yield "a"; })() : AsyncGenerator<string, void, undefined>
+>(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, undefined>
+>async function * () { yield "a"; } : () => AsyncGenerator<string, void, undefined>
+>yield "a" : undefined
 >"a" : "a"
 
 };
@@ -147,10 +147,10 @@ async function * explicitReturnType3(): AsyncIterableIterator<number> {
 
     yield* (async function * () { yield "a"; })();
 >yield* (async function * () { yield "a"; })() : void
->(async function * () { yield "a"; })() : AsyncGenerator<string, void, unknown>
->(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, unknown>
->async function * () { yield "a"; } : () => AsyncGenerator<string, void, unknown>
->yield "a" : any
+>(async function * () { yield "a"; })() : AsyncGenerator<string, void, undefined>
+>(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, undefined>
+>async function * () { yield "a"; } : () => AsyncGenerator<string, void, undefined>
+>yield "a" : undefined
 >"a" : "a"
 }
 async function * explicitReturnType4(): AsyncIterable<number> {
@@ -174,10 +174,10 @@ async function * explicitReturnType6(): AsyncIterable<number> {
 
     yield* (async function * () { yield "a"; })();
 >yield* (async function * () { yield "a"; })() : void
->(async function * () { yield "a"; })() : AsyncGenerator<string, void, unknown>
->(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, unknown>
->async function * () { yield "a"; } : () => AsyncGenerator<string, void, unknown>
->yield "a" : any
+>(async function * () { yield "a"; })() : AsyncGenerator<string, void, undefined>
+>(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, undefined>
+>async function * () { yield "a"; } : () => AsyncGenerator<string, void, undefined>
+>yield "a" : undefined
 >"a" : "a"
 }
 async function * explicitReturnType7(): AsyncIterator<number> {
@@ -201,10 +201,10 @@ async function * explicitReturnType9(): AsyncIterator<number> {
 
     yield* (async function * () { yield "a"; })();
 >yield* (async function * () { yield "a"; })() : void
->(async function * () { yield "a"; })() : AsyncGenerator<string, void, unknown>
->(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, unknown>
->async function * () { yield "a"; } : () => AsyncGenerator<string, void, unknown>
->yield "a" : any
+>(async function * () { yield "a"; })() : AsyncGenerator<string, void, undefined>
+>(async function * () { yield "a"; }) : () => AsyncGenerator<string, void, undefined>
+>async function * () { yield "a"; } : () => AsyncGenerator<string, void, undefined>
+>yield "a" : undefined
 >"a" : "a"
 }
 async function * explicitReturnType10(): IterableIterator<number> {
diff --git a/tests/cases/compiler/contextualReturnTypeOfIIFE.ts b/tests/cases/compiler/contextualReturnTypeOfIIFE.ts
new file mode 100644
index 0000000000000..b4497cdd4ec10
--- /dev/null
+++ b/tests/cases/compiler/contextualReturnTypeOfIIFE.ts
@@ -0,0 +1,13 @@
+// @lib: esnext
+
+const test1: Promise<[one: number, two: string]> = (async () => {
+    return [1, 'two'];
+})();
+
+const test2: Promise<[one: number, two: string]> = new Promise(
+    (resolve) => resolve([1, 'two']),
+);
+
+const obj: { foo: [one: number, two: string] } = {
+    foo: (() => [1, 'two'])()
+};