Converted Test File

some-test_spec.js

import { expect } from 'chai';

// how a test might have been written Mocha.
describe('addition', () => {
  context('a sane universe', () => {
    test('one plus two equals three', () => {
      expect(1 + 2).to.equal(3);
    });
  });
});

// how the same test works with our Jest implementation.
describe('addition', () => {
  // context only works in Jest here because of the previous snippet
  context('a sane universe', () => {
    // This is the only line that has changed `test` => `it`
    it('one plus two equals three', () => {
      expect(1 + 2).to.equal(3);
    });
  });
});