import dispatch, { init, worker } from './dispatcher-main';

jest.mock('./get-worker', () => ({
  getWorker: () => ({
    port: {
      postMessage: jest.fn(),
    },
  }),
}));

describe('The dispatcher-main', () => {
  beforeEach(() => {
    init();
  });
  test('should create a new shared web worker', () => {
    expect(worker).toBeDefined();
  });
  test('should create a onmessage function', () => {
    expect(worker.port.onmessage).toBeDefined();
  });
  test('should return a promise if no callback is provided', () => {
    expect(dispatch('ping')).toBeInstanceOf(Promise);
  });
  test('should forward the message', () => {
    dispatch('ping');
    expect(worker.port.postMessage).toBeCalledWith({ id: 0, payload: 'ping' });
  });
  test('should return the response', () => {
    var response;
    const callback = (error, success) => {
      response = success;
    };
    dispatch('ping', callback);
    worker.port.onmessage({ data: { id: 0, payload: 'pong' } });
    expect(response).toEqual('pong');
  });
});