ds-algo-study/DS-n-Algos/_Extra-Practice/events/test.js

Just experimenting with publishing a package

const Events = require('./index');

test('Events can be registered then triggered', () => {
  const events = new Events();

  const cb1 = jest.fn();

  events.on('click', cb1);
  events.trigger('click');

  expect(cb1.mock.calls.length).toBe(1);
});

test('Multiple events can be registered then triggered', () => {
  const events = new Events();

  const cb1 = jest.fn();
  const cb2 = jest.fn();

  events.on('click', cb1);
  events.on('click', cb2);
  events.trigger('click');

  expect(cb1.mock.calls.length).toBe(1);
  expect(cb2.mock.calls.length).toBe(1);
});

test('Events can be triggered multiple times', () => {
  const events = new Events();

  const cb1 = jest.fn();
  const cb2 = jest.fn();

  events.on('click', cb1);
  events.trigger('click');
  events.on('click', cb2);
  events.trigger('click');
  events.trigger('click');

  expect(cb1.mock.calls.length).toBe(3);
  expect(cb2.mock.calls.length).toBe(2);
});

test('Events can have different names', () => {
  const events = new Events();

  const cb1 = jest.fn();
  const cb2 = jest.fn();

  events.on('click', cb1);
  events.trigger('click');
  events.on('hover', cb2);
  events.trigger('click');
  events.trigger('hover');

  expect(cb1.mock.calls.length).toBe(2);
  expect(cb2.mock.calls.length).toBe(1);
});

test('Events can be toggled off', () => {
  const events = new Events();

  const cb1 = jest.fn();
  const cb2 = jest.fn();

  events.on('hover', cb2);

  events.on('click', cb1);
  events.trigger('click');
  events.off('click');
  events.trigger('click');

  events.trigger('hover');

  expect(cb1.mock.calls.length).toBe(1);
  expect(cb2.mock.calls.length).toBe(1);
});