RN: Flowify packages/react-native/jest

Author: yungsters

flow-typed/npm/jest.js

@@ -853,6 +853,10 @@ type JestObjectType = {
    * Returns the number of fake timers still left to run.
    */
   getTimerCount(): number,
+  /**
+   * Returns the time in ms of the current clock.
+   */
+  now(): number,
   /**
    * Set the current system time used by fake timers.
    * Simulates a user changing the system clock while your program is running.

packages/react-native/jest/MockNativeMethods.js

@@ -4,10 +4,11 @@
  * 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
  */
 
-'use strict';
+import type {LegacyHostInstanceMethods} from "../src/private/types/HostInstance";
 
 const MockNativeMethods = {
   measure: jest.fn(),
@@ -16,6 +17,13 @@ const MockNativeMethods = {
   setNativeProps: jest.fn(),
   focus: jest.fn(),
   blur: jest.fn(),
+} as {
+  measure: () => void,
+  measureInWindow: () => void,
+  measureLayout: () => void,
+  setNativeProps: () => void,
+  focus: () => void,
+  blur: () => void,
 };
 
-module.exports = MockNativeMethods;
+export default MockNativeMethods;

packages/react-native/jest/RefreshControlMock.js

@@ -21,10 +21,12 @@ const RCTRefreshControl: HostComponent<{}> = requireNativeComponent<{}>(
 
 export default class RefreshControlMock extends React.Component<{...}> {
   static latestRef: ?RefreshControlMock;
+
+  render(): React.Node {
+    return <RCTRefreshControl />;
+  }
+
   componentDidMount() {
     RefreshControlMock.latestRef = this;
   }
-  render(): React.MixedElement {
-    return <RCTRefreshControl />;
-  }
 }

packages/react-native/jest/assetFileTransformer.js

@@ -4,6 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
+ * @noflow
  * @format
  */
 

packages/react-native/jest/local-setup.js

@@ -4,24 +4,25 @@
  * 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
  */
 
 // Global setup for tests local to the react-native repo. This setup is not
 // included in the react-native Jest preset.
 
-'use strict';
-
-require('./setup');
+import './setup';
 
 const consoleError = console.error;
 const consoleWarn = console.warn;
 
+// $FlowIgnore[cannot-write]
 console.error = (...args) => {
   consoleError(...args);
   throw new Error('console.error() was called (see error above)');
 };
 
+// $FlowIgnore[cannot-write]
 console.warn = (...args) => {
   consoleWarn(...args);
   throw new Error('console.warn() was called (see warning above)');

packages/react-native/jest/mockComponent.js

@@ -4,37 +4,50 @@
  * 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
  */
 
-'use strict';
+import * as React from 'react';
+import {createElement} from 'react';
 
-module.exports = (moduleName, instanceMethods, isESModule) => {
-  const RealComponent = isESModule
-    ? jest.requireActual(moduleName).default
-    : jest.requireActual(moduleName);
-  const React = require('react');
+type Modulish<T> = T | $ReadOnly<{default: T}>;
 
-  const SuperClass =
+type TComponentType = React.ComponentType<$ReadOnly<{children?: React.Node}>>;
+
+export default function mockComponent<TComponentModule: Modulish<TComponentType>>(
+  moduleName: string,
+  instanceMethods: ?interface {},
+  isESModule: boolean,
+): (typeof isESModule extends true ? TComponentModule['default'] : TComponentModule) & typeof instanceMethods {
+  const RealComponent =
+    isESModule
+    // $FlowIgnore[incompatible-cast]
+    ? (jest.requireActual<TComponentModule>(moduleName) as $ReadOnly<{default: TComponentType}>).default
+    // $FlowIgnore[incompatible-cast]
+    : jest.requireActual<TComponentModule>(moduleName) as TComponentType;
+
+  const SuperClass: typeof React.Component<React.ElementProps<typeof RealComponent>> =
     typeof RealComponent === 'function' &&
     RealComponent.prototype.constructor instanceof React.Component
       ? RealComponent
       : React.Component;
 
   const name =
-    RealComponent.displayName ||
-    RealComponent.name ||
-    (RealComponent.render // handle React.forwardRef
-      ? RealComponent.render.displayName || RealComponent.render.name
-      : 'Unknown');
+    RealComponent.displayName ??
+    RealComponent.name ??
+    // $FlowFixMe[incompatible-use] - Checking for `forwardRef` values.
+    // $FlowFixMe[prop-missing]
+    (RealComponent.render == null ? 'Unknown' : RealComponent.render.displayName ?? RealComponent.render.name);
 
   const nameWithoutPrefix = name.replace(/^(RCT|RK)/, '');
 
   const Component = class extends SuperClass {
-    static displayName = 'Component';
+    static displayName: ?string = 'Component';
 
-    render() {
-      const props = Object.assign({}, RealComponent.defaultProps);
+    render(): React.Node {
+      // $FlowIgnore[prop-missing]
+      const props = {...RealComponent.defaultProps};
 
       if (this.props) {
         Object.keys(this.props).forEach(prop => {
@@ -49,7 +62,8 @@ module.exports = (moduleName, instanceMethods, isESModule) => {
         });
       }
 
-      return React.createElement(nameWithoutPrefix, props, this.props.children);
+      // $FlowIgnore[not-a-function]
+      return createElement(nameWithoutPrefix, props, this.props.children);
     }
   };
 
@@ -62,13 +76,16 @@ module.exports = (moduleName, instanceMethods, isESModule) => {
 
   Component.displayName = nameWithoutPrefix;
 
+  // $FlowIgnore[not-an-object]
   Object.keys(RealComponent).forEach(classStatic => {
     Component[classStatic] = RealComponent[classStatic];
   });
 
   if (instanceMethods != null) {
+    // $FlowIgnore[unsafe-object-assign]
     Object.assign(Component.prototype, instanceMethods);
   }
 
+  // $FlowIgnore[incompatible-return]
   return Component;
 };

packages/react-native/jest/mockModal.js

@@ -4,19 +4,18 @@
  * 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
+ * @flow strict
  * @format
  */
 
-/* eslint-env jest */
+import * as React from 'react';
 
-'use strict';
-
-const React = require('react');
-
-function mockModal(BaseComponent: $FlowFixMe) {
-  class ModalMock extends BaseComponent {
-    render(): React.MixedElement | null {
+export default function mockModal(
+  BaseComponent: React.ComponentType<{children?: React.Node}>,
+): React.ComponentType<{...React.ElementConfig<typeof BaseComponent>, visible?: ?boolean}> {
+  // $FlowIgnore[incompatible-use]
+  return class ModalMock extends BaseComponent {
+    render(): React.Node {
       if (this.props.visible === false) {
         return null;
       }
@@ -26,7 +25,4 @@ function mockModal(BaseComponent: $FlowFixMe) {
       );
     }
   }
-  return ModalMock;
 }
-
-module.exports = (mockModal: $FlowFixMe);

packages/react-native/jest/mockNativeComponent.js

@@ -4,31 +4,38 @@
  * 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
  */
 
-'use strict';
+import type {HostInstance} from '../src/private/types/HostInstance';
 
-const React = require('react');
-const {createElement} = require('react');
+import * as React from 'react';
+import {createElement} from 'react';
 
 let nativeTag = 1;
 
-export default viewName => {
-  const Component = class extends React.Component {
-    _nativeTag = nativeTag++;
+type MockNativeComponent<TProps: $ReadOnly<{children?: React.Node}>> =
+  component(ref?: ?React.RefSetter<HostInstance>, ...props: TProps);
 
-    render() {
+export default function mockNativeComponent<
+  TProps: $ReadOnly<{children?: React.Node}>,
+>(viewName: string): MockNativeComponent<TProps> {
+  const Component = class extends React.Component<TProps> {
+    _nativeTag: number = nativeTag++;
+
+    render(): React.Node {
+      // $FlowIgnore[not-a-function]
       return createElement(viewName, this.props, this.props.children);
     }
 
     // The methods that exist on host components
-    blur = jest.fn();
-    focus = jest.fn();
-    measure = jest.fn();
-    measureInWindow = jest.fn();
-    measureLayout = jest.fn();
-    setNativeProps = jest.fn();
+    blur: () => void = jest.fn();
+    focus: () => void = jest.fn();
+    measure: () => void = jest.fn();
+    measureInWindow: () => void = jest.fn();
+    measureLayout: () => void = jest.fn();
+    setNativeProps: () => void = jest.fn();
   };
 
   if (viewName === 'RCTView') {
@@ -38,4 +45,4 @@ export default viewName => {
   }
 
   return Component;
-};
+}

packages/react-native/jest/mockScrollView.js

@@ -8,19 +8,20 @@
  * @format
  */
 
-/* eslint-env jest */
+import type {ScrollViewNativeProps} from "../Libraries/Components/ScrollView/ScrollViewNativeComponentType";
 
-'use strict';
+import View from '../Libraries/Components/View/View';
+import requireNativeComponent from '../Libraries/ReactNative/requireNativeComponent';
+import * as React from 'react';
 
-const View = require('../Libraries/Components/View/View').default;
-const requireNativeComponent =
-  require('../Libraries/ReactNative/requireNativeComponent').default;
-const React = require('react');
-const RCTScrollView: $FlowFixMe = requireNativeComponent('RCTScrollView');
+const RCTScrollView = requireNativeComponent<ScrollViewNativeProps>('RCTScrollView');
 
-function mockScrollView(BaseComponent: $FlowFixMe) {
-  class ScrollViewMock extends BaseComponent {
-    render(): React.MixedElement {
+export default function mockScrollView(
+  BaseComponent: React.ComponentType<{children?: React.Node}>,
+): React.ComponentType<{...React.ElementConfig<typeof BaseComponent>, refreshControl?: ?React.MixedElement}> {
+  // $FlowIgnore[incompatible-use]
+  return class ScrollViewMock extends BaseComponent {
+    render(): React.Node {
       return (
         <RCTScrollView {...this.props}>
           {this.props.refreshControl}
@@ -29,7 +30,4 @@ function mockScrollView(BaseComponent: $FlowFixMe) {
       );
     }
   }
-  return ScrollViewMock;
 }
-
-module.exports = (mockScrollView: $FlowFixMe);

packages/react-native/jest/react-native-env.js

@@ -4,6 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
+ * @noflow
  * @format
  */
 

packages/react-native/jest/renderer.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict
  * @format
  */
 

packages/react-native/jest/resolver.js

@@ -4,6 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
+ * @noflow
  * @format
  */