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

describe('The dispatcher-main', () => {
  var postMessage = jest.fn();
  beforeEach(() => {
    global.SharedWorker = jest.fn(function (source) {
      this.source = source;
      this.port = {
        postMessage,
      };
      return this;
    });
    init();
  });
  test('should create a new shared web worker', () => {
    expect(SharedWorker).toBeCalled();
  });
  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 send back the message', () => {
    dispatch('ping');
    expect(postMessage).toBeCalledWith({ id: 0, payload: 'ping' });
  });
});