export default function createDeferred() {
  throw new Error('Not implemented');
}

import createDeferred from './createDeferred';

describe('createDeferred', () => {
  test('resolves when resolve is called', async () => {
    const d = createDeferred();
    d.resolve(123);
    const out = await d.promise;
    expect(out).toBe(123);
  });

  test('rejects when reject is called', async () => {
    const d = createDeferred();
    const err = new Error('nope');
    d.reject(err);

    try {
      await d.promise;
      throw new Error('Expected promise to reject');
    } catch (e) {
      expect(e).toBe(err);
    }
  });

  test('adopts another promise when resolving', async () => {
    const d = createDeferred();
    d.resolve(Promise.resolve('ok'));
    const out = await d.promise;
    expect(out).toBe('ok');
  });
});