on.js

(function (window) {
  var Muuri = window.Muuri;

  QUnit.module('Grid methods');

  QUnit.test('on: should return the instance', function (assert) {
    assert.expect(1);

    var container = utils.createGridElements();
    var grid = new Muuri(container);
    var teardown = function () {
      grid.destroy();
      container.parentNode.removeChild(container);
    };

    assert.strictEqual(
      grid.on('foo', function () {}),
      grid
    );
    teardown();
  });

  QUnit.test('on: should bind an event listener', function (assert) {
    assert.expect(1);

    var container = utils.createGridElements();
    var grid = new Muuri(container);
    var calls = 0;
    var callback = function () {
      ++calls;
    };
    var teardown = function () {
      grid.destroy();
      container.parentNode.removeChild(container);
    };

    grid.on('synchronize', callback);
    grid.synchronize().synchronize().synchronize();
    assert.strictEqual(calls, 3, 'should execute the listeners when event is emitted');
    teardown();
  });
})(this);