Snapshot testing #

Earl supports Jest's snapshots tests. Only toMatchSnapshot is supported right now - no inline snapshots support.

Basic usage #

import { expect } from 'earljs'

describe('snapshots', () => {
  it('work', () => {
    expect({ very: { nested: { wow: 'wow' } } }).toMatchSnapshot()
  })
})

Matches actual value to a snapshot. The name of the snapshot is derived from the suite and test case names. A snapshot will be created under __snapshot__ folder.

If a snapshot doesn't exist, it will be created. If it exists, actual values will be asserted against it. Set UPDATE_SNAPSHOTS=true environment variable to update snapshots instead. On CI no snapshots will be updated/created.

Multiple snapshots in one test case work as expected.

Requires test runner integration.

Read more #

• Jest documentation about snapshot testing
• Effective snapshot testing (MUST READ)