RN: Refactor Jest Default Mocks

.flowconfig

@@ -69,6 +69,8 @@ module.name_mapper='^react-native/\(.*\)$' -> '<PROJECT_ROOT>/packages/react-nat
 module.name_mapper='^@react-native/dev-middleware$' -> '<PROJECT_ROOT>/packages/dev-middleware'
 module.name_mapper='^@?[./a-zA-Z0-9$_-]+\.\(bmp\|gif\|jpg\|jpeg\|png\|psd\|svg\|webp\|m4v\|mov\|mp4\|mpeg\|mpg\|webm\|aac\|aiff\|caf\|m4a\|mp3\|wav\|html\|pdf\|xml\)$' -> '<PROJECT_ROOT>/packages/react-native/Libraries/Image/RelativeImageStub'
 
+module.system.haste.module_ref_prefix=m#
+
 react.runtime=automatic
 
 suppress_type=$FlowIssue

packages/react-native/jest/mock.js

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ * @oncall react_native
+ */
+
+/**
+ * Mocks the module referenced by `moduleRef` (expected to begin with `m#`)
+ * while enforcing type safety of mock factories.
+ *
+ * If `factoryRef` is provided, it is expected to reference a module that
+ * exports the same type signature as the module referenced by `moduleRef`.
+ */
+export default function mock<TModuleRef: $Flow$ModuleRef<mixed>>(
+  moduleRef: TModuleRef,
+  factoryRef?: NoInfer<TModuleRef>,
+): void {
+  // NOTE: Jest's `babel-plugin-jest-hoist` requires that the second argument to
+  // `jest.mock` be an inline function, so structure this code accordingly.
+  if (factoryRef === undefined) {
+    jest.mock(deref(moduleRef));
+  } else {
+    // NOTE: Jest's `babel-plugin-jest-hoist` requires that module factories
+    // only reference local variables or variables starting with "mock", so be
+    // careful when renaming this `mockFactory` variable.
+    const mockFactory = deref(factoryRef);
+    jest.mock(deref(moduleRef), () => jest.requireActual(mockFactory));
+  }
+}
+
+function deref(ref: $Flow$ModuleRef<mixed>): string {
+  // $FlowIgnore[incompatible-cast]
+  return (ref as string).substring(2);
+}

packages/react-native/jest/mockComponent.js

@@ -14,16 +14,20 @@ import {createElement} from 'react';
 type Modulish<T> = T | $ReadOnly<{default: T}>;
 type ModuleDefault<T> = T['default'];
 
-type TComponentType = React.ComponentType<$ReadOnly<{children?: React.Node}>>;
+type TComponentType = React.ComponentType<{...}>;
 
+/**
+ * WARNING: The `moduleName` must be relative to this file's directory, which is
+ * a major footgun. Be careful when using this function!
+ */
 export default function mockComponent<
   TComponentModule: Modulish<TComponentType>,
 >(
   moduleName: string,
   instanceMethods: ?interface {},
   isESModule: boolean,
 ): typeof isESModule extends true
-  ? ModuleDefault<TComponentModule>
+  ? ModuleDefault<TComponentModule & typeof instanceMethods>
   : TComponentModule & typeof instanceMethods {
   const RealComponent: TComponentType = isESModule
     ? // $FlowIgnore[prop-missing]
@@ -71,6 +75,7 @@ export default function mockComponent<
       }
 
       // $FlowIgnore[not-a-function]
+      // $FlowIgnore[prop-missing]
       return createElement(nameWithoutPrefix, props, this.props.children);
     }
   };

packages/react-native/jest/mockNativeComponent.js

@@ -15,17 +15,20 @@ import {createElement} from 'react';
 
 let nativeTag = 1;
 
-type MockNativeComponent<TProps: $ReadOnly<{children?: React.Node}>> =
-  component(ref?: ?React.RefSetter<HostInstance>, ...props: TProps);
-
-export default function mockNativeComponent<
-  TProps: $ReadOnly<{children?: React.Node}>,
->(viewName: string): MockNativeComponent<TProps> {
+type MockNativeComponent<TProps: {...}> = component(
+  ref?: ?React.RefSetter<HostInstance>,
+  ...props: TProps
+);
+
+export default function mockNativeComponent<TProps: {...}>(
+  viewName: string,
+): MockNativeComponent<TProps> {
   const Component = class extends React.Component<TProps> {
     _nativeTag: number = nativeTag++;
 
     render(): React.Node {
       // $FlowIgnore[not-a-function]
+      // $FlowIgnore[prop-missing]
       return createElement(viewName, this.props, this.props.children);
     }
 

packages/react-native/jest/mocks/AccessibilityInfo.js

@@ -0,0 +1,62 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ */
+
+const AccessibilityInfo = {
+  addEventListener: jest.fn(() => ({
+    remove: jest.fn(),
+  })) as JestMockFn<$FlowFixMe, {remove: JestMockFn<[], void>}>,
+  announceForAccessibility: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  announceForAccessibilityWithOptions: jest.fn() as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  isAccessibilityServiceEnabled: jest.fn(() =>
+    Promise.resolve(false),
+  ) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  isBoldTextEnabled: jest.fn(() => Promise.resolve(false)) as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  isGrayscaleEnabled: jest.fn(() => Promise.resolve(false)) as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  isInvertColorsEnabled: jest.fn(() => Promise.resolve(false)) as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  isReduceMotionEnabled: jest.fn(() => Promise.resolve(false)) as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  isHighTextContrastEnabled: jest.fn(() =>
+    Promise.resolve(false),
+  ) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  isDarkerSystemColorsEnabled: jest.fn(() =>
+    Promise.resolve(false),
+  ) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  prefersCrossFadeTransitions: jest.fn(() =>
+    Promise.resolve(false),
+  ) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  isReduceTransparencyEnabled: jest.fn(() =>
+    Promise.resolve(false),
+  ) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  isScreenReaderEnabled: jest.fn(() => Promise.resolve(false)) as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  setAccessibilityFocus: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  sendAccessibilityEvent: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  getRecommendedTimeoutMillis: jest.fn(() =>
+    Promise.resolve(false),
+  ) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+};
+
+export default AccessibilityInfo;

packages/react-native/jest/mocks/ActivityIndicator.js

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import typeof TActivityIndicator from '../../Libraries/Components/ActivityIndicator/ActivityIndicator';
+import typeof * as TmockComponent from '../mockComponent';
+
+const mockComponent =
+  jest.requireActual<TmockComponent>('../mockComponent').default;
+
+const ActivityIndicator = mockComponent(
+  '../Libraries/Components/ActivityIndicator/ActivityIndicator',
+  null, // instanceMethods
+  true, // isESModule
+) as TActivityIndicator;
+
+export default ActivityIndicator;

packages/react-native/jest/mocks/AppState.js

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ */
+
+const AppState = {
+  addEventListener: jest.fn(() => ({
+    remove: jest.fn(),
+  })) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  removeEventListener: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  currentState: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+};
+
+export default AppState;

packages/react-native/jest/mocks/Clipboard.js

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ */
+
+const Clipboard = {
+  getString: jest.fn(async () => '') as JestMockFn<[], Promise<string>>,
+  setString: jest.fn() as JestMockFn<[string], void>,
+};
+
+export default Clipboard;

packages/react-native/jest/mocks/Image.js

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import typeof TImage from '../../Libraries/Image/Image';
+import typeof * as TmockComponent from '../mockComponent';
+
+const mockComponent =
+  jest.requireActual<TmockComponent>('../mockComponent').default;
+
+const Image = mockComponent(
+  '../Libraries/Image/Image',
+  null, // instanceMethods
+  true, // isESModule
+) as TImage;
+
+export default Image;

packages/react-native/jest/mocks/InitializeCore.js

@@ -0,0 +1,9 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ */

packages/react-native/jest/mocks/Linking.js

@@ -0,0 +1,28 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ */
+
+const Linking = {
+  openURL: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  canOpenURL: jest.fn(() => Promise.resolve(true)) as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  openSettings: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  addEventListener: jest.fn(() => ({
+    remove: jest.fn(),
+  })) as JestMockFn<$FlowFixMe, $FlowFixMe>,
+  getInitialURL: jest.fn(() => Promise.resolve()) as JestMockFn<
+    $FlowFixMe,
+    $FlowFixMe,
+  >,
+  sendIntent: jest.fn() as JestMockFn<$FlowFixMe, $FlowFixMe>,
+};
+
+export default Linking;

packages/react-native/jest/mocks/Modal.js

@@ -0,0 +1,33 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import type {ModalProps} from '../../Libraries/Modal/Modal';
+import typeof * as TmockComponent from '../mockComponent';
+
+const mockComponent =
+  jest.requireActual<TmockComponent>('../mockComponent').default;
+
+type TModal = component(...ModalProps);
+
+const BaseComponent = mockComponent(
+  '../Libraries/Modal/Modal',
+  null, // instanceMethods
+  true, // isESModule
+) as TModal;
+
+// $FlowIgnore[incompatible-use]
+export default class Modal extends BaseComponent {
+  render(): React.Node {
+    if (this.props.visible === false) {
+      return null;
+    }
+    return <BaseComponent {...this.props}>{this.props.children}</BaseComponent>;
+  }
+}