Add restoreMocks config to fix #3580 (#5327)

* Added restoreMocks config option

* Changed tests to use jest.spyOn, since that's what restore impacts

* Changed tests to use correct toHaveBeenCalled() syntax

* Added changelog entry

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 * `[jest-cli]` Fix `EISDIR` when a directory is passed as an argument to `jest`.
   ([#5317](https://github.com/facebook/jest/pull/5317))
+* `[jest-config]` Added restoreMocks config option.
+  ([#5327](https://github.com/facebook/jest/pull/5327))
 
 ## jest 22.1.0
 

docs/Configuration.md

@@ -605,6 +605,15 @@ argument:
 The function should either return a path to the module that should be resolved
 or throw an error if the module can't be found.
 
+### `restoreMocks` [boolean]
+
+Default: `false`
+
+Automatically restore mock state between every test. Equivalent to calling
+`jest.restoreAllMocks()` between each test. This will lead to any mocks having
+their fake implementations removed and restores their initial
+implementation.
+
 ### `rootDir` [string]
 
 Default: The root of the directory containing your jest's [config file](#) _or_

docs/MockFunctionAPI.md

@@ -96,6 +96,9 @@ Beware that `mockFn.mockRestore` only works when mock was created with
 `jest.spyOn`. Thus you have to take care of restoration yourself when manually
 assigning `jest.fn()`.
 
+The [`restoreMocks`](configuration.html#restoremocks-boolean) configuration
+option is available to restore mocks automatically between tests.
+
 ### `mockFn.mockImplementation(fn)`
 
 Accepts a function that should be used as the implementation of the mock. The

integration-tests/__tests__/__snapshots__/show_config.test.js.snap

@@ -32,6 +32,7 @@ exports[`--showConfig outputs config info and exits 1`] = `
       \\"name\\": \\"[md5 hash]\\",
       \\"resetMocks\\": false,
       \\"resetModules\\": false,
+      \\"restoreMocks\\": false,
       \\"rootDir\\": \\"<<REPLACED_ROOT_DIR>>\\",
       \\"roots\\": [
         \\"<<REPLACED_ROOT_DIR>>\\"

integration-tests/__tests__/auto_restore_mocks.test.js

@@ -0,0 +1,21 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. 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.
+ *
+ * @flow
+ */
+'use strict';
+
+const runJest = require('../runJest');
+
+test('suite with auto-restore', () => {
+  const result = runJest('auto-restore-mocks/with-auto-restore');
+  expect(result.status).toBe(0);
+});
+
+test('suite without auto-restore', () => {
+  const result = runJest('auto-restore-mocks/without-auto-restore');
+  expect(result.status).toBe(0);
+});

integration-tests/auto-restore-mocks/with-auto-restore/__tests__/index.js

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. 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.
+ */
+
+'use strict';
+
+const TestClass = require('../');
+const localClass = new TestClass();
+
+test('first test', () => {
+  jest.spyOn(localClass, 'test').mockImplementation(() => 'ABCD');
+  expect(localClass.test()).toEqual('ABCD');
+  expect(localClass.test).toHaveBeenCalledTimes(1);
+});
+
+test('second test', () => {
+  expect(localClass.test()).toEqual('12345');
+  expect(localClass.test.mock).toBe(undefined);
+});

integration-tests/auto-restore-mocks/with-auto-restore/index.js

@@ -0,0 +1,12 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. 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.
+ */
+
+module.exports = class Test {
+  test() {
+    return '12345';
+  }
+};

integration-tests/auto-restore-mocks/with-auto-restore/package.json

@@ -0,0 +1,6 @@
+{
+  "jest": {
+    "testEnvironment": "node",
+    "restoreMocks": true
+  }
+}

integration-tests/auto-restore-mocks/without-auto-restore/__tests__/index.js

@@ -0,0 +1,42 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. 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.
+ */
+
+'use strict';
+
+const TestClass = require('../');
+const localClass = new TestClass();
+
+describe('without an explicit restore', () => {
+  jest.spyOn(localClass, 'test').mockImplementation(() => 'ABCD');
+
+  test('first test', () => {
+    expect(localClass.test()).toEqual('ABCD');
+    expect(localClass.test).toHaveBeenCalledTimes(1);
+  });
+
+  test('second test', () => {
+    expect(localClass.test()).toEqual('ABCD');
+    expect(localClass.test).toHaveBeenCalledTimes(2);
+  });
+});
+
+describe('with an explicit restore', () => {
+  beforeEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  test('first test', () => {
+    jest.spyOn(localClass, 'test').mockImplementation(() => 'ABCD');
+    expect(localClass.test()).toEqual('ABCD');
+    expect(localClass.test).toHaveBeenCalledTimes(1);
+  });
+
+  test('second test', () => {
+    expect(localClass.test()).toEqual('12345');
+    expect(localClass.test.mock).toBe(undefined);
+  });
+});

integration-tests/auto-restore-mocks/without-auto-restore/index.js

@@ -0,0 +1,12 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. 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.
+ */
+
+module.exports = class Test {
+  test() {
+    return '12345';
+  }
+};

integration-tests/auto-restore-mocks/without-auto-restore/package.json

@@ -0,0 +1,5 @@
+{
+  "jest": {
+    "testEnvironment": "node"
+  }
+}

packages/jest-circus/src/legacy_code_todo_rewrite/jest_adapter.js

@@ -52,6 +52,10 @@ const jestAdapter = async (
       runtime.resetAllMocks();
     }
 
+    if (config.restoreMocks) {
+      runtime.restoreAllMocks();
+    }
+
     if (config.timers === 'fake') {
       environment.fakeTimers.useFakeTimers();
     }

packages/jest-cli/src/cli/args.js

@@ -411,6 +411,13 @@ export const options = {
     description: 'A JSON string which allows the use of a custom resolver.',
     type: 'string',
   },
+  restoreMocks: {
+    default: undefined,
+    description:
+      'Automatically restore mock state and implementation between every test. ' +
+      'Equivalent to calling jest.restoreAllMocks() between each test.',
+    type: 'boolean',
+  },
   rootDir: {
     description:
       'The root directory that Jest should scan for tests and ' +

packages/jest-config/src/defaults.js

@@ -55,6 +55,7 @@ export default ({
   preset: null,
   resetMocks: false,
   resetModules: false,
+  restoreMocks: false,
   runTestsByPath: false,
   runner: 'jest-runner',
   snapshotSerializers: [],

packages/jest-config/src/index.js

@@ -162,6 +162,7 @@ const getConfigs = (
       resetMocks: options.resetMocks,
       resetModules: options.resetModules,
       resolver: options.resolver,
+      restoreMocks: options.restoreMocks,
       rootDir: options.rootDir,
       roots: options.roots,
       runner: options.runner,

packages/jest-config/src/normalize.js

@@ -487,6 +487,7 @@ export default function normalize(options: InitialOptions, argv: Argv) {
       case 'reporters':
       case 'resetMocks':
       case 'resetModules':
+      case 'restoreMocks':
       case 'rootDir':
       case 'runTestsByPath':
       case 'silent':

packages/jest-config/src/valid_config.js

@@ -70,6 +70,7 @@ export default ({
   resetMocks: false,
   resetModules: false,
   resolver: '<rootDir>/resolver.js',
+  restoreMocks: false,
   rootDir: '/',
   roots: ['<rootDir>'],
   runTestsByPath: false,

packages/jest-jasmine2/src/index.js

@@ -89,6 +89,10 @@ async function jasmine2(
         environment.fakeTimers.useFakeTimers();
       }
     }
+
+    if (config.restoreMocks) {
+      runtime.restoreAllMocks();
+    }
   });
 
   env.addReporter(reporter);

packages/jest-validate/src/__tests__/fixtures/jest_config.js

@@ -42,6 +42,7 @@ const defaultConfig = {
   preset: null,
   resetMocks: false,
   resetModules: false,
+  restoreMocks: false,
   roots: ['<rootDir>'],
   snapshotSerializers: [],
   testEnvironment: 'jest-environment-jsdom',
@@ -98,6 +99,7 @@ const validConfig = {
   preset: 'react-native',
   resetMocks: false,
   resetModules: false,
+  restoreMocks: false,
   rootDir: '/',
   roots: ['<rootDir>'],
   setupFiles: ['<rootDir>/setup.js'],

test_utils.js

@@ -85,6 +85,7 @@ const DEFAULT_PROJECT_CONFIG: ProjectConfig = {
   resetMocks: false,
   resetModules: false,
   resolver: null,
+  restoreMocks: false,
   rootDir: '/test_root_dir/',
   roots: [],
   runner: 'jest-runner',

types/Argv.js

@@ -60,6 +60,7 @@ export type Argv = {|
   resetMocks: boolean,
   resetModules: boolean,
   resolver: ?string,
+  restoreMocks: boolean,
   rootDir: string,
   roots: Array<string>,
   setupFiles: Array<string>,

types/Config.js

@@ -47,6 +47,7 @@ export type DefaultOptions = {|
   preset: ?string,
   resetMocks: boolean,
   resetModules: boolean,
+  restoreMocks: boolean,
   runner: string,
   runTestsByPath: boolean,
   snapshotSerializers: Array<Path>,
@@ -117,6 +118,7 @@ export type InitialOptions = {
   resetMocks?: boolean,
   resetModules?: boolean,
   resolver?: ?Path,
+  restoreMocks?: boolean,
   rootDir: Path,
   roots?: Array<Path>,
   runner?: string,
@@ -227,6 +229,7 @@ export type ProjectConfig = {|
   resetMocks: boolean,
   resetModules: boolean,
   resolver: ?Path,
+  restoreMocks: boolean,
   rootDir: Path,
   roots: Array<Path>,
   runner: string,