jest-snapshot 29.7.0

Jest-snapshot is an efficient testing package that forms an important module of the Jest framework. It enables developers to capture snapshots of test values and compare them with the current state of the system in order to detect any unexpected changes that may have been introduced. This approach primarily aids in spot-checking large objects and providing record-replay features for JavaScript testing.

To effectively use Jest-snapshot, you’ll need to have the Jest testing framework installed in your system. While creating tests, you can use the toMatchSnapshot() or toThrowErrorMatchingSnapshot() methods from Jest to create or update snapshots. Jest-snapshot becomes involved whenever these snapshot methods are used. Here's a quick example:

import renderer from 'react-test-renderer';
import Link from '../Link.react';

it('renders correctly', () => {
    const tree = renderer
    .create(<Link page="http://www.facebook.com">Facebook</Link>)
    .toJSON();
    expect(tree).toMatchSnapshot();
});

In this example, a snapshot of the rendered <Link /> component is taken and saved. When the test runs, Jest compares the rendered output with the previously saved snapshot. If they match, the test passes; otherwise, the test fails.

For in-depth information about Jest-snapshot, you can refer to Jest's official documentation. This comprehensive guide covers every detail about snapshot testing with Jest, providing valuable insights on how to best use Jest-snapshot in your testing workflow. The guide includes topics like updating snapshots, property matchers, and inline snapshots.