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<meta name="viewport" content="width=device-width, minimum-scale=1.0, initial-scale=1.0, user-scalable=yes">
<title>gr-fixed-panel</title>

<script src="../../../bower_components/webcomponentsjs/webcomponents-lite.min.js"></script>
<script src="../../../bower_components/web-component-tester/browser.js"></script>

<link rel="import" href="gr-fixed-panel.html">

<script>void(0);</script>

<test-fixture id="basic">
  <template>
    <gr-fixed-panel>
      <div style="height: 100px"></div>
    </gr-fixed-panel>
  </template>
</test-fixture>

<script>
  suite('gr-fixed-panel', () => {
    let element;
    let sandbox;

    setup(() => {
      element = fixture('basic');
      sandbox = sinon.sandbox.create();
    });

    teardown(() => {
      sandbox.restore();
    });

    test('header is the height of the content', () => {
      assert.equal(element.getBoundingClientRect().height, 100);
    });

    test('scroll triggers _handleScroll', () => {
      sandbox.stub(element, '_handleScroll');
      window.dispatchEvent(new CustomEvent('scroll'));
      assert.isTrue(element._handleScroll.called);
    });

    suite('_handleScroll', () => {
      const getHeaderTop = function() {
        return element.$.header.style.top;
      };

      const emulateScrollY = function(distance) {
        element._getScrollY.returns(distance);
        element._handleScroll();
        element.flushDebouncer('scroll');
      };

      setup(() => {
        element._headerTopInitial = 10;
        sandbox.stub(element, '_getScrollY').returns(0);
      });

      test('is debounced', () => {
        sandbox.stub(element, 'debounce');
        element._handleScroll();
        assert.isTrue(element.debounce.called);
      });

      test('scrolls header along with document', () => {
        emulateScrollY(20);
        assert.equal(getHeaderTop(), '-10px');
      });

      test('does not stick to the top by default', () => {
        emulateScrollY(150);
        assert.equal(getHeaderTop(), '-140px');
      });

      test('sticks to the top if enabled', () => {
        element.keepOnScroll = true;
        emulateScrollY(120);
        assert.equal(getHeaderTop(), '0px');
      });
    });
  });
</script>