Expect-mocha-snapshot NPM

expect-mocha-snapshot

expect extension to use Jest's toMatchSnapshot in Mocha

The module uses jest-snapshot under the hood and works as an extension to expect@1.20.x to enable snapshot-testing in mocha.

See the blog post about snapshot-testing in Mocha here.

Usage

const expect = require('expect');
const toMatchSnapshot = require('expect-mocha-snapshot');

expect.extend({ toMatchSnapshot });

describe('foo', function () {
  it('matches the snapshot', function () {
    expect({ foo: 'bar' }).toMatchSnapshot(this);
  });
});

To create the snapshot or test the code against the created snapshots, just run mocha like you normally would.

mocha

If your tests are failing and you want to update the snapshot, use the environment variable SNAPSHOT_UPDATE.

SNAPSHOT_UPDATE=true mocha

Compatibility

Compatibility with expect and jest-snapshot is a moving target. The 2.x has been tested with "expect": "^26.1.0", "jest-snapshot": "^26.1.0" and "mocha": "^8.0.1"

For lower versions of jest-snapshot and expect stick to 1.x release.