Feat(breaking): unify wait for element signature with testing library

README.md

@@ -118,7 +118,7 @@ The [public API](https://callstack.github.io/react-native-testing-library/docs/a
 
 - [`render`](https://callstack.github.io/react-native-testing-library/docs/api#render) – deeply renders given React element and returns helpers to query the output components.
 - [`fireEvent`](https://callstack.github.io/react-native-testing-library/docs/api#fireevent) - invokes named event handler on the element.
-- [`waitForElement`](https://callstack.github.io/react-native-testing-library/docs/api#waitforelement) - waits for non-deterministic periods of time until your element appears or times out.
+- [`waitFor`](https://callstack.github.io/react-native-testing-library/docs/api#waitfor) - waits for non-deterministic periods of time until your element appears or times out.
 - [`within`](https://callstack.github.io/react-native-testing-library/docs/api#within) - creates a queries object scoped for given element.
 - [`flushMicrotasksQueue`](https://callstack.github.io/react-native-testing-library/docs/api#flushmicrotasksqueue) - waits for microtasks queue to flush.
 

src/__tests__/waitForElement.test.js → src/__tests__/waitFor.test.js

@@ -1,7 +1,7 @@
 // @flow
 import React from 'react';
 import { View, Text, TouchableOpacity } from 'react-native';
-import { render, fireEvent, waitForElement } from '..';
+import { render, fireEvent, waitFor } from '..';
 
 class Banana extends React.Component<any> {
   changeFresh = () => {
@@ -42,7 +42,7 @@ test('waits for element until it stops throwing', async () => {
 
   expect(queryByText('Fresh')).toBeNull();
 
-  const freshBananaText = await waitForElement(() => getByText('Fresh'));
+  const freshBananaText = await waitFor(() => getByText('Fresh'));
 
   expect(freshBananaText.props.children).toBe('Fresh');
 });
@@ -52,7 +52,9 @@ test('waits for element until timeout is met', async () => {
 
   fireEvent.press(getByName('TouchableOpacity'));
 
-  await expect(waitForElement(() => getByText('Fresh'), 100)).rejects.toThrow();
+  await expect(
+    waitFor(() => getByText('Fresh'), { timeout: 100 })
+  ).rejects.toThrow();
 });
 
 test('waits for element with custom interval', async () => {
@@ -61,7 +63,7 @@ test('waits for element with custom interval', async () => {
   });
 
   try {
-    await waitForElement(() => mockFn(), 400, 200);
+    await waitFor(() => mockFn(), { timeout: 400, interval: 200 });
   } catch (e) {
     // suppress
   }
@@ -77,7 +79,7 @@ test('works with fake timers', async () => {
   });
 
   try {
-    waitForElement(() => mockFn(), 400, 200);
+    waitFor(() => mockFn(), { timeout: 400, interval: 200 });
   } catch (e) {
     // suppress
   }

src/helpers/a11yAPI.js

@@ -1,6 +1,6 @@
 // @flow
 import type { A11yRole, A11yStates, A11yState, A11yValue } from '../types.flow';
-import type { WaitForOptions } from './findByAPI';
+import type { WaitForOptions } from '../waitFor';
 import makeQuery from './makeQuery';
 
 type GetReturn = ReactTestInstance;

src/helpers/findByAPI.js

@@ -1,5 +1,6 @@
 // @flow
-import waitForElement from '../waitForElement';
+import waitFor from '../waitFor';
+import type { WaitForOptions } from '../waitFor';
 import {
   getByTestId,
   getAllByTestId,
@@ -11,22 +12,12 @@ import {
   getAllByDisplayValue,
 } from './getByAPI';
 
-export type WaitForOptions = {
-  timeout?: number,
-  interval?: number,
-};
-
 const makeFindQuery = <Text, Result>(
   instance: ReactTestInstance,
   getQuery: (instance: ReactTestInstance) => (text: Text) => Result,
   text: Text,
   waitForOptions: WaitForOptions
-): Promise<Result> =>
-  waitForElement(
-    () => getQuery(instance)(text),
-    waitForOptions.timeout,
-    waitForOptions.interval
-  );
+): Promise<Result> => waitFor(() => getQuery(instance)(text), waitForOptions);
 
 export const findByTestId = (instance: ReactTestInstance) => (
   testId: string,

src/helpers/makeQuery.js

@@ -1,11 +1,11 @@
 // @flow
-import waitForElement from '../waitForElement';
+import waitFor from '../waitFor';
+import type { WaitForOptions } from '../waitFor';
 import {
   ErrorWithStack,
   prepareErrorMessage,
   createQueryByError,
 } from './errors';
-import type { WaitForOptions } from './findByAPI';
 
 function isNodeValid(node: ReactTestInstance) {
   return typeof node.type === 'string';
@@ -70,19 +70,11 @@ const makeQuery = <P: mixed, M: mixed>(
   };
 
   const findBy = (matcher: M, waitForOptions?: WaitForOptions) => {
-    return waitForElement(
-      () => getBy(matcher),
-      waitForOptions?.timeout,
-      waitForOptions?.interval
-    );
+    return waitFor(() => getBy(matcher), waitForOptions);
   };
 
   const findAllBy = (matcher: M, waitForOptions?: WaitForOptions) => {
-    return waitForElement(
-      () => getAllBy(matcher),
-      waitForOptions?.timeout,
-      waitForOptions?.interval
-    );
+    return waitFor(() => getAllBy(matcher), waitForOptions);
   };
 
   return {

src/index.js

@@ -5,7 +5,7 @@ import fireEvent from './fireEvent';
 import flushMicrotasksQueue from './flushMicrotasksQueue';
 import render from './render';
 import shallow from './shallow';
-import waitForElement from './waitForElement';
+import waitFor from './waitFor';
 import within from './within';
 
 export { act };
@@ -14,5 +14,5 @@ export { fireEvent };
 export { flushMicrotasksQueue };
 export { render };
 export { shallow };
-export { waitForElement };
+export { waitFor };
 export { within };

src/waitForElement.js → src/waitFor.js

@@ -1,10 +1,21 @@
 // @flow
-export default function waitForElement<T>(
+
+const DEFAULT_TIMEOUT = 4500;
+const DEFAULT_INTERVAL = 50;
+
+export type WaitForOptions = {
+  timeout?: number,
+  interval?: number,
+};
+
+export default function waitFor<T>(
   expectation: () => T,
-  timeout: number = 4500,
-  interval: number = 50
+  options?: WaitForOptions
 ): Promise<T> {
+  const timeout = options?.timeout ?? DEFAULT_TIMEOUT;
+  const interval = options?.interval ?? DEFAULT_INTERVAL;
   const startTime = Date.now();
+
   return new Promise((resolve, reject) => {
     const rejectOrRerun = (error) => {
       if (Date.now() - startTime >= timeout) {

typings/__tests__/index.test.tsx

@@ -6,7 +6,7 @@ import {
   fireEvent,
   shallow,
   flushMicrotasksQueue,
-  waitForElement,
+  waitFor,
   act,
   within,
 } from '../..';
@@ -250,12 +250,13 @@ const shallowTree: { output: React.ReactElement<any> } = shallow(
 
 const waitForFlush: Promise<any> = flushMicrotasksQueue();
 
-const waitBy: Promise<ReactTestInstance> = waitForElement<ReactTestInstance>(
-  () => tree.getByName('View')
+const waitBy: Promise<ReactTestInstance> = waitFor<ReactTestInstance>(() =>
+  tree.getByName('View')
+);
+const waitByAll: Promise<ReactTestInstance[]> = waitFor<ReactTestInstance[]>(
+  () => tree.getAllByName('View'),
+  { timeout: 1000, interval: 50 }
 );
-const waitByAll: Promise<Array<ReactTestInstance>> = waitForElement<
-  Array<ReactTestInstance>
->(() => tree.getAllByName('View'), 1000, 50);
 
 act(() => {
   render(<TestComponent />);

typings/index.d.ts

@@ -224,10 +224,14 @@ export type FireEventAPI = FireEventFunction & {
   scroll: (element: ReactTestInstance, ...data: Array<any>) => any;
 };
 
-export type WaitForElementFunction = <T = any>(
+type WaitForOptions = {
+  timeout?: number;
+  interval?: number;
+};
+
+export type WaitForFunction = <T = any>(
   expectation: () => T,
-  timeout?: number,
-  interval?: number
+  options?: WaitForOptions
 ) => Promise<T>;
 
 export declare const render: (
@@ -240,6 +244,6 @@ export declare const shallow: <P = {}>(
 export declare const flushMicrotasksQueue: () => Promise<any>;
 export declare const cleanup: () => void;
 export declare const fireEvent: FireEventAPI;
-export declare const waitForElement: WaitForElementFunction;
+export declare const waitFor: WaitForFunction;
 export declare const act: (callback: () => void) => Thenable;
 export declare const within: (instance: ReactTestInstance) => Queries;

website/docs/API.md

@@ -313,29 +313,28 @@ fireEvent.scroll(getByType(ScrollView), eventData);
 expect(onEndReached).toHaveBeenCalled();
 ```
 
-## `waitForElement`
+## `waitFor`
 
-- [`Example code`](https://github.com/callstack/react-native-testing-library/blob/master/src/__tests__/waitForElement.test.js)
+- [`Example code`](https://github.com/callstack/react-native-testing-library/blob/master/src/__tests__/waitFor.test.js)
 
 Defined as:
 
 ```jsx
-function waitForElement<T>(
+function waitFor<T>(
   expectation: () => T,
-  timeout: number = 4500,
-  interval: number = 50
+  { timeout: number = 4500, interval: number = 50 }
 ): Promise<T> {}
 ```
 
-Waits for non-deterministic periods of time until your element appears or times out. `waitForElement` periodically calls `expectation` every `interval` milliseconds to determine whether the element appeared or not.
+Waits for non-deterministic periods of time until your element appears or times out. `waitFor` periodically calls `expectation` every `interval` milliseconds to determine whether the element appeared or not.
 
 ```jsx
-import { render, waitForElement } from 'react-testing-library';
+import { render, waitFor } from 'react-testing-library';
 
 test('waiting for an Banana to be ready', async () => {
   const { getByText } = render(<Banana />);
 
-  await waitForElement(() => getByText('Banana ready'));
+  await waitFor(() => getByText('Banana ready'));
 });
 ```
 

website/docs/Migration20.md

@@ -5,6 +5,35 @@ title: Migration to 2.0
 
 This guides describes major steps involved in migrating your testing code from using React Native Testing Library version `1.x` to version `2.0`.
 
+## WaitFor API changes
+
+`waitForElement` function has been renamed to `waitFor` for consistency with React Testing Library. Additionally the signature has slightly changed from:
+
+```jsx
+export default function waitForElement<T>(
+  expectation: () => T,
+  timeout?: number,
+  interval?: number
+ : Promise<T> {
+```
+
+to:
+
+```jsx
+export default function waitFor<T>(
+  expectation: () => T,
+  {
+    timeout?: number,
+    interval?: number
+  }
+): Promise<T> {
+```
+
+Both changes should improve code readibility.
+
+:::note
+Please note that in many cases `waitFor` call can be replaced by proper use of `findBy` asynchonous queries resulting in more streamlined test code.
+:::
 
 ## Removed global `debug` function
 

website/docs/Queries.md

@@ -33,7 +33,7 @@ title: Queries
 `findAllBy` queries return a promise which resolves to an array when any matching elements are found. The promise is rejected if no elements match after a default timeout of 4500ms.
 
 :::info
-`findBy` and `findAllBy` queries accept optional `waitForOptions` object argument which can contain `timeout` and `interval` properies which have the same meaning as respective arguments to [`waitForElement`](https://callstack.github.io/react-native-testing-library/docs/api#waitforelement) function.
+`findBy` and `findAllBy` queries accept optional `waitForOptions` object argument which can contain `timeout` and `interval` properies which have the same meaning as respective options for [`waitFor`](https://callstack.github.io/react-native-testing-library/docs/api#waitfor) function.
 :::
 
 ## Queries