der.step = 1;
            done();
        });
      });

      test('tracking', function(done) {
        var sliderWidth = slider.$.sliderBar.getBoundingClientRect().width;
        slider.min = 0;
        slider.max = 2;
        slider.step = 1;
        slider.value = 0;

        MockInteractions.track(slider.$.sliderBar, sliderWidth * 0.9, 0);

        flush(function() {
          assert.equal(slider.value, slider.max);
          done();
        });
      });

      test('value should notify', function(don