@spalger/kibana/src/ui/public/debounce/__tests__/debounce.js

Kibana is an open source (Apache Licensed), browser based analytics and search dashboard for Elasticsearch. Kibana is a snap to setup and start using. Kibana strives to be easy to get started with, while also being flexible and powerful, just like Elastic

var sinon = require('auto-release-sinon');
var expect = require('expect.js');
var ngMock = require('ngMock');

var debounce;
var $timeout;
var $timeoutSpy;

function init() {
  ngMock.module('kibana');

  ngMock.inject(function ($injector, _$timeout_) {
    $timeout = _$timeout_;
    $timeoutSpy = sinon.spy($timeout);

    debounce = $injector.get('debounce');
  });
}

describe('debounce service', function () {
  var spy;
  beforeEach(function () {
    spy = sinon.spy(function () {});
    init();
  });

  describe('API', function () {
    it('should have a cancel method', function () {
      var bouncer = debounce(function () {}, 100);
      expect(bouncer).to.have.property('cancel');
    });
  });

  describe('delayed execution', function () {
    it('should delay execution', function () {
      var bouncer = debounce(spy, 100);
      bouncer();
      expect(spy.callCount).to.be(0);
      $timeout.flush();
      expect(spy.callCount).to.be(1);
    });

    it('should fire on leading edge', function () {
      var bouncer = debounce(spy, 100, { leading: true });
      bouncer();
      expect(spy.callCount).to.be(1);
      $timeout.flush();
      expect(spy.callCount).to.be(2);
    });

    it('should only fire on leading edge', function () {
      var bouncer = debounce(spy, 100, { leading: true, trailing: false });
      bouncer();
      expect(spy.callCount).to.be(1);
      $timeout.flush();
      expect(spy.callCount).to.be(1);
    });

    it('should reset delayed execution', function (done) {
      var cancelSpy = sinon.spy($timeout, 'cancel');
      var bouncer = debounce(spy, 100);
      bouncer();
      setTimeout(function () {
        bouncer();
        expect(spy.callCount).to.be(0);
        $timeout.flush();
        expect(spy.callCount).to.be(1);
        expect(cancelSpy.callCount).to.be(1);
        done();
      }, 1);
    });
  });

  describe('cancel', function () {
    it('should cancel the $timeout', function () {
      var cancelSpy = sinon.spy($timeout, 'cancel');
      var bouncer = debounce(spy, 100);
      bouncer();
      bouncer.cancel();
      expect(cancelSpy.callCount).to.be(1);
      $timeout.verifyNoPendingTasks(); // throws if pending timeouts
    });
  });
});