From a653a6ffdcf0ba82891bfb068dcb87da4facbca7 Mon Sep 17 00:00:00 2001
From: Tom Mrazauskas <tom@mrazauskas.de>
Date: Wed, 23 Feb 2022 15:59:25 +0200
Subject: [PATCH] refactor(jest-mock)!: rename and clean up utility types
 (#12435)

---
 CHANGELOG.md                                  |   1 +
 .../__typetests__/utility-types.test.ts       | 103 ++++++++++++++
 packages/jest-mock/src/index.ts               | 133 +++++++++---------
 3 files changed, 172 insertions(+), 65 deletions(-)
 create mode 100644 packages/jest-mock/__typetests__/utility-types.test.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f0e7bb57f87f..a0a2dbd41e21 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@
 - `[jest-environment-node]` [**BREAKING**] Second argument `context` to constructor is mandatory ([#12469](https://github.com/facebook/jest/pull/12469))
 - `[@jest/expect]` New module which extends `expect` with `jest-snapshot` matchers ([#12404](https://github.com/facebook/jest/pull/12404), [#12410](https://github.com/facebook/jest/pull/12410), [#12418](https://github.com/facebook/jest/pull/12418))
 - `[@jest/expect-utils]` New module exporting utils for `expect` ([#12323](https://github.com/facebook/jest/pull/12323))
+- `[jest-mock]` [**BREAKING**] Rename exported utility types `ConstructorLike`, `MethodLike`, `ConstructorLikeKeys`, `MethodLikeKeys`, `PropertyLikeKeys`; remove exports of utility types `ArgumentsOf`, `ArgsType`, `ConstructorArgumentsOf` - TS builtin utility types `ConstructorParameters` and `Parameters` should be used instead ([#12435](https://github.com/facebook/jest/pull/12435))
 - `[jest-mock]` Improve `isMockFunction` to infer types of passed function ([#12442](https://github.com/facebook/jest/pull/12442))
 - `[jest-resolve]` [**BREAKING**] Add support for `package.json` `exports` ([#11961](https://github.com/facebook/jest/pull/11961), [#12373](https://github.com/facebook/jest/pull/12373))
 - `[jest-resolve, jest-runtime]` Add support for `data:` URI import and mock ([#12392](https://github.com/facebook/jest/pull/12392))
diff --git a/packages/jest-mock/__typetests__/utility-types.test.ts b/packages/jest-mock/__typetests__/utility-types.test.ts
new file mode 100644
index 000000000000..af4efdb60a49
--- /dev/null
+++ b/packages/jest-mock/__typetests__/utility-types.test.ts
@@ -0,0 +1,103 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {expectAssignable, expectNotAssignable, expectType} from 'tsd-lite';
+import type {
+  ConstructorLike,
+  ConstructorLikeKeys,
+  MethodLike,
+  MethodLikeKeys,
+  PropertyLikeKeys,
+} from 'jest-mock';
+
+class SomeClass {
+  propertyB = 123;
+  private _propertyC: undefined;
+  #propertyD = 'abc';
+
+  constructor(public propertyA: string) {}
+
+  methodA(): void {
+    return;
+  }
+
+  methodB(b: string): string {
+    return b;
+  }
+
+  get propertyC() {
+    return this._propertyC;
+  }
+  set propertyC(value) {
+    this._propertyC = value;
+  }
+}
+
+const someObject = {
+  SomeClass,
+
+  methodA() {
+    return;
+  },
+  methodB(b: string) {
+    return true;
+  },
+  methodC: (c: number) => true,
+
+  propertyA: 123,
+  propertyB: 'value',
+
+  someClassInstance: new SomeClass('value'),
+};
+
+type SomeObject = typeof someObject;
+
+// ClassLike
+
+expectAssignable<ConstructorLike>(SomeClass);
+expectNotAssignable<ConstructorLike>(() => {});
+expectNotAssignable<ConstructorLike>(function abc() {
+  return;
+});
+expectNotAssignable<ConstructorLike>('abc');
+expectNotAssignable<ConstructorLike>(123);
+expectNotAssignable<ConstructorLike>(false);
+expectNotAssignable<ConstructorLike>(someObject);
+
+// FunctionLike
+
+expectAssignable<MethodLike>(() => {});
+expectAssignable<MethodLike>(function abc() {
+  return;
+});
+expectNotAssignable<MethodLike>('abc');
+expectNotAssignable<MethodLike>(123);
+expectNotAssignable<MethodLike>(false);
+expectNotAssignable<MethodLike>(SomeClass);
+expectNotAssignable<MethodLike>(someObject);
+
+// ConstructorKeys
+
+declare const constructorKeys: ConstructorLikeKeys<SomeObject>;
+
+expectType<'SomeClass'>(constructorKeys);
+
+// MethodKeys
+
+declare const classMethods: MethodLikeKeys<SomeClass>;
+declare const objectMethods: MethodLikeKeys<SomeObject>;
+
+expectType<'methodA' | 'methodB'>(classMethods);
+expectType<'methodA' | 'methodB' | 'methodC'>(objectMethods);
+
+// PropertyKeys
+
+declare const classProperties: PropertyLikeKeys<SomeClass>;
+declare const objectProperties: PropertyLikeKeys<SomeObject>;
+
+expectType<'propertyA' | 'propertyB' | 'propertyC'>(classProperties);
+expectType<'propertyA' | 'propertyB' | 'someClassInstance'>(objectProperties);
diff --git a/packages/jest-mock/src/index.ts b/packages/jest-mock/src/index.ts
index bae820bde600..16fee2a2addc 100644
--- a/packages/jest-mock/src/index.ts
+++ b/packages/jest-mock/src/index.ts
@@ -20,87 +20,101 @@ export type MockFunctionMetadataType =
 export type MockFunctionMetadata<
   T,
   Y extends Array<unknown>,
-  Type = MockFunctionMetadataType,
+  MetadataType = MockFunctionMetadataType,
 > = {
   ref?: number;
   members?: Record<string, MockFunctionMetadata<T, Y>>;
   mockImpl?: (...args: Y) => T;
   name?: string;
   refID?: number;
-  type?: Type;
+  type?: MetadataType;
   value?: T;
   length?: number;
 };
 
-export type MockableFunction = (...args: Array<any>) => any;
-export type MethodKeysOf<T> = {
-  [K in keyof T]: T[K] extends MockableFunction ? K : never;
+export type ConstructorLike = {new (...args: Array<any>): any};
+
+export type MethodLike = (...args: Array<any>) => any;
+
+export type ConstructorLikeKeys<T> = {
+  [K in keyof T]: T[K] extends ConstructorLike ? K : never;
 }[keyof T];
-export type PropertyKeysOf<T> = {
-  [K in keyof T]: T[K] extends MockableFunction ? never : K;
+
+export type MethodLikeKeys<T> = {
+  [K in keyof T]: T[K] extends MethodLike ? K : never;
 }[keyof T];
 
-export type ArgumentsOf<T> = T extends (...args: infer A) => any ? A : never;
+export type PropertyLikeKeys<T> = {
+  [K in keyof T]: T[K] extends MethodLike
+    ? never
+    : T[K] extends ConstructorLike
+    ? never
+    : K;
+}[keyof T];
 
-export type ConstructorArgumentsOf<T> = T extends new (...args: infer A) => any
-  ? A
+// TODO Figure out how to replace this with TS ConstructorParameters utility type
+// https://www.typescriptlang.org/docs/handbook/utility-types.html#constructorparameterstype
+type ConstructorParameters<T> = T extends new (...args: infer P) => any
+  ? P
   : never;
+
 export type MaybeMockedConstructor<T> = T extends new (
   ...args: Array<any>
 ) => infer R
-  ? MockInstance<R, ConstructorArgumentsOf<T>>
+  ? MockInstance<R, ConstructorParameters<T>>
   : T;
-export type MockedFunction<T extends MockableFunction> = MockWithArgs<T> & {
+
+export interface MockWithArgs<T extends MethodLike>
+  extends MockInstance<ReturnType<T>, Parameters<T>> {
+  new (...args: ConstructorParameters<T>): T;
+  (...args: Parameters<T>): ReturnType<T>;
+}
+
+export type MockedFunction<T extends MethodLike> = MockWithArgs<T> & {
   [K in keyof T]: T[K];
 };
-export type MockedFunctionDeep<T extends MockableFunction> = MockWithArgs<T> &
+
+export type MockedFunctionDeep<T extends MethodLike> = MockWithArgs<T> &
   MockedObjectDeep<T>;
+
 export type MockedObject<T> = MaybeMockedConstructor<T> & {
-  [K in MethodKeysOf<T>]: T[K] extends MockableFunction
+  [K in MethodLikeKeys<T>]: T[K] extends MethodLike
     ? MockedFunction<T[K]>
     : T[K];
-} & {[K in PropertyKeysOf<T>]: T[K]};
+} & {[K in PropertyLikeKeys<T>]: T[K]};
+
 export type MockedObjectDeep<T> = MaybeMockedConstructor<T> & {
-  [K in MethodKeysOf<T>]: T[K] extends MockableFunction
+  [K in MethodLikeKeys<T>]: T[K] extends MethodLike
     ? MockedFunctionDeep<T[K]>
     : T[K];
-} & {[K in PropertyKeysOf<T>]: MaybeMockedDeep<T[K]>};
+} & {[K in PropertyLikeKeys<T>]: MaybeMockedDeep<T[K]>};
 
-export type MaybeMockedDeep<T> = T extends MockableFunction
-  ? MockedFunctionDeep<T>
+export type MaybeMocked<T> = T extends MethodLike
+  ? MockedFunction<T>
   : T extends object
-  ? MockedObjectDeep<T>
+  ? MockedObject<T>
   : T;
 
-export type MaybeMocked<T> = T extends MockableFunction
-  ? MockedFunction<T>
+export type MaybeMockedDeep<T> = T extends MethodLike
+  ? MockedFunctionDeep<T>
   : T extends object
-  ? MockedObject<T>
+  ? MockedObjectDeep<T>
   : T;
 
-export type ArgsType<T> = T extends (...args: infer A) => any ? A : never;
 export type Mocked<T> = {
-  [P in keyof T]: T[P] extends (...args: Array<any>) => any
-    ? MockInstance<ReturnType<T[P]>, ArgsType<T[P]>>
-    : T[P] extends Constructable
+  [P in keyof T]: T[P] extends MethodLike
+    ? MockInstance<ReturnType<T[P]>, Parameters<T[P]>>
+    : T[P] extends ConstructorLike
     ? MockedClass<T[P]>
     : T[P];
 } & T;
-export type MockedClass<T extends Constructable> = MockInstance<
+
+export type MockedClass<T extends ConstructorLike> = MockInstance<
   InstanceType<T>,
   T extends new (...args: infer P) => any ? P : never
 > & {
   prototype: T extends {prototype: any} ? Mocked<T['prototype']> : never;
 } & T;
-export interface Constructable {
-  new (...args: Array<any>): any;
-}
-
-export interface MockWithArgs<T extends MockableFunction>
-  extends MockInstance<ReturnType<T>, ArgumentsOf<T>> {
-  new (...args: ConstructorArgumentsOf<T>): T;
-  (...args: ArgumentsOf<T>): ReturnType<T>;
-}
 
 export interface Mock<T, Y extends Array<unknown> = Array<unknown>>
   extends Function,
@@ -109,8 +123,9 @@ export interface Mock<T, Y extends Array<unknown> = Array<unknown>>
   (...args: Y): T;
 }
 
-export interface SpyInstance<T, Y extends Array<unknown>>
-  extends MockInstance<T, Y> {}
+// TODO Replace with Awaited utility type when minimum supported TS version will be 4.5 or above
+//https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-5.html#the-awaited-type-and-promise-improvements
+type Unpromisify<T> = T extends Promise<infer R> ? R : never;
 
 export interface MockInstance<T, Y extends Array<unknown>> {
   _isMockFunction: true;
@@ -137,7 +152,8 @@ export interface MockInstance<T, Y extends Array<unknown>> {
   mockRejectedValueOnce(value: unknown): this;
 }
 
-type Unpromisify<T> = T extends Promise<infer R> ? R : never;
+export interface SpyInstance<T, Y extends Array<unknown>>
+  extends MockInstance<T, Y> {}
 
 type MockFunctionResultIncomplete = {
   type: 'incomplete';
@@ -200,20 +216,6 @@ type MockFunctionConfig = {
   specificMockImpls: Array<Function>;
 };
 
-// see https://github.com/Microsoft/TypeScript/issues/25215
-type NonFunctionPropertyNames<T> = {
-  [K in keyof T]: T[K] extends (...args: Array<any>) => any ? never : K;
-}[keyof T] &
-  string;
-type FunctionPropertyNames<T> = {
-  [K in keyof T]: T[K] extends (...args: Array<any>) => any ? K : never;
-}[keyof T] &
-  string;
-type ConstructorPropertyNames<T> = {
-  [K in keyof T]: T[K] extends new (...args: Array<any>) => any ? K : never;
-}[keyof T] &
-  string;
-
 const MOCK_CONSTRUCTOR_NAME = 'mockConstructor';
 
 const FUNCTION_NAME_RESERVED_PATTERN = /[\s!-\/:-@\[-`{-~]/;
@@ -1036,34 +1038,34 @@ export class ModuleMocker {
     return fn;
   }
 
-  spyOn<T extends object, M extends NonFunctionPropertyNames<T>>(
+  spyOn<T extends object, M extends PropertyLikeKeys<T>>(
     object: T,
     methodName: M,
     accessType: 'get',
   ): SpyInstance<T[M], []>;
 
-  spyOn<T extends object, M extends NonFunctionPropertyNames<T>>(
+  spyOn<T extends object, M extends PropertyLikeKeys<T>>(
     object: T,
     methodName: M,
     accessType: 'set',
   ): SpyInstance<void, [T[M]]>;
 
-  spyOn<T extends object, M extends ConstructorPropertyNames<T>>(
+  spyOn<T extends object, M extends ConstructorLikeKeys<T>>(
     object: T,
     methodName: M,
-  ): T[M] extends new (...args: Array<any>) => any
+  ): T[M] extends ConstructorLike
     ? SpyInstance<InstanceType<T[M]>, ConstructorParameters<T[M]>>
     : never;
 
-  spyOn<T extends object, M extends FunctionPropertyNames<T>>(
+  spyOn<T extends object, M extends MethodLikeKeys<T>>(
     object: T,
     methodName: M,
-  ): T[M] extends (...args: Array<any>) => any
+  ): T[M] extends MethodLike
     ? SpyInstance<ReturnType<T[M]>, Parameters<T[M]>>
     : never;
 
   // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
-  spyOn<T extends object, M extends NonFunctionPropertyNames<T>>(
+  spyOn<T extends object, M extends PropertyLikeKeys<T>>(
     object: T,
     methodName: M,
     accessType?: 'get' | 'set',
@@ -1134,10 +1136,11 @@ export class ModuleMocker {
     return object[methodName];
   }
 
-  private _spyOnProperty<
-    T extends object,
-    M extends NonFunctionPropertyNames<T>,
-  >(obj: T, propertyName: M, accessType: 'get' | 'set' = 'get'): Mock<T> {
+  private _spyOnProperty<T extends object, M extends PropertyLikeKeys<T>>(
+    obj: T,
+    propertyName: M,
+    accessType: 'get' | 'set' = 'get',
+  ): Mock<T> {
     if (typeof obj !== 'object' && typeof obj !== 'function') {
       throw new Error(
         'Cannot spyOn on a primitive value; ' + this._typeOf(obj) + ' given',