@enact/core/dispatcher/tests/dispatcher-specs.js

Enact is an open source JavaScript framework containing everything you need to create a fast, scalable mobile or web application.

"use strict";

var _dispatcher = require("../dispatcher");
describe('dispatcher', function () {
  test('should register handlers on target', function () {
    var handler = jest.fn();
    (0, _dispatcher.on)('localechange', handler, window);
    var ev = new window.CustomEvent('localechange', {});
    window.dispatchEvent(ev);
    var expected = 1;
    expect(handler).toHaveBeenCalledTimes(expected);
  });
  test('should not register duplicate handlers on target', function () {
    var handler = jest.fn();
    (0, _dispatcher.on)('localechange', handler, window);
    (0, _dispatcher.on)('localechange', handler, window);
    var ev = new window.CustomEvent('localechange', {});
    window.dispatchEvent(ev);
    var expected = 1;
    expect(handler).toHaveBeenCalledTimes(expected);
  });
  test('should unregister handlers on target', function () {
    var handler = jest.fn();
    (0, _dispatcher.on)('localechange', handler, window);
    var ev = new window.CustomEvent('localechange', {});
    window.dispatchEvent(ev);
    (0, _dispatcher.off)('localechange', handler, window);
    window.dispatchEvent(ev);
    var expected = 1;
    expect(handler).toHaveBeenCalledTimes(expected);
  });
  test('should only call a "once" handler once', function () {
    var handler = jest.fn();
    (0, _dispatcher.once)('localechange', handler, window);
    var ev = new window.CustomEvent('localechange', {});
    window.dispatchEvent(ev);
    window.dispatchEvent(ev);
    var expected = 1;
    expect(handler).toHaveBeenCalledTimes(expected);
  });
  test('should allow unregistering a "once" before it is called', function () {
    var handler = jest.fn();
    var onceHandler = (0, _dispatcher.once)('localechange', handler, window);
    (0, _dispatcher.off)('localechange', onceHandler, window);
    var ev = new window.CustomEvent('localechange', {});
    window.dispatchEvent(ev);
    expect(handler).not.toHaveBeenCalled();
  });
  test('should not block subsequent handlers when a handler throws', function () {
    // Modify the console spy to silence error output with
    // an empty mock implementation
    // eslint-disable-next-line no-console
    console.error.mockImplementation();
    var _throws = function _throws() {
      throw new Error('Thrown from handler');
    };
    var handler = jest.fn();
    (0, _dispatcher.on)('localechange', _throws, window);
    (0, _dispatcher.on)('localechange', handler, window);
    var ev = new window.CustomEvent('localechange', {});
    window.dispatchEvent(ev);
    var expected = 1;
    expect(handler).toHaveBeenCalledTimes(expected);
  });
});