Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://callstack.github.io/react-native-testing-library/docs/api/misc/other below:

Other helpers - React Native Testing Library

function within(element: ReactTestInstance): Queries {}

function getQueriesForElement(element: ReactTestInstance): Queries {}

within (also available as getQueriesForElement alias) performs queries scoped to given element.

NOTE

Please note that additional render specific operations like update, unmount, debug, toJSON are not included.

const detailsScreen = within(screen.getByA11yHint('Details Screen'));
expect(detailsScreen.getByText('Some Text')).toBeOnTheScreen();
expect(detailsScreen.getByDisplayValue('Some Value')).toBeOnTheScreen();
expect(detailsScreen.queryByLabelText('Some Label')).toBeOnTheScreen();
await expect(detailsScreen.findByA11yHint('Some Label')).resolves.toBeOnTheScreen();

Use cases for scoped queries include:

• queries scoped to a single item inside a FlatList containing many items
• queries scoped to a single screen in tests involving screen transitions (e.g. with react-navigation)

Useful function to help testing components that use hooks API. By default any render, update, fireEvent, and waitFor calls are wrapped by this function, so there is no need to wrap it manually. This method is re-exported from react-test-renderer.

Consult our Understanding Act function document for more understanding of its intricacies.

const cleanup: () => void;

Unmounts React trees that were mounted with render and clears screen variable that holds latest render output.

INFO

Please note that this is done automatically if the testing framework you're using supports the afterEach global (like mocha, Jest, and Jasmine). If not, you will need to do manual cleanups after each test.

For example, if you're using the jest testing framework, then you would need to use the afterEach hook like so:

import { cleanup, render } from '@testing-library/react-native/pure';
import { View } from 'react-native';

afterEach(cleanup);

it('renders a view', () => {
  render(<View />);
  // ...
});

The afterEach(cleanup) call also works in describe blocks:

describe('when logged in', () => {
  afterEach(cleanup);

  it('renders the user', () => {
    render(<SiteHeader />);
    // ...
  });
});

Failing to call cleanup when you've called render could result in a memory leak and tests which are not "idempotent" (which can lead to difficult to debug errors in your tests).

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4