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

<script src="../../../bower_components/webcomponentsjs/webcomponents.min.js"></script>
<script src="../../../bower_components/web-component-tester/browser.js"></script>
<script src="../../../scripts/util.js"></script>
<script src="../gr-diff/gr-diff-line.js"></script>
<script src="../gr-diff/gr-diff-group.js"></script>
<script src="../gr-diff-highlight/gr-annotation.js"></script>
<script src="gr-diff-builder.js"></script>

<link rel="import" href="../../shared/gr-rest-api-interface/mock-diff-response_test.html">
<link rel="import" href="gr-diff-builder.html">

<test-fixture id="basic">
  <template>
    <gr-diff-builder>
      <table id="diffTable"></table>
    </gr-diff-builder>
  </template>
</test-fixture>

<test-fixture id="div-with-text">
  <template>
    <div>Lorem ipsum dolor sit amet, suspendisse inceptos vehicula</div>
  </template>
</test-fixture>

<test-fixture id="mock-diff">
  <template>
    <gr-diff-builder view-mode="SIDE_BY_SIDE">
      <table id="diffTable"></table>
    </gr-diff-builder>
  </template>
</test-fixture>

<script>
  suite('gr-diff-builder tests', function() {
    var element;
    var builder;

    setup(function() {
      stub('gr-rest-api-interface', {
        getLoggedIn: function() { return Promise.resolve(false); },
      });
      var prefs = {
        line_length: 10,
        show_tabs: true,
        tab_size: 4,
      };
      builder = new GrDiffBuilder({content: []}, {left: [], right: []}, prefs);
    });

    test('context control buttons', function() {
      var section = {};
      var line = {contextGroup: {lines: []}};

      // Create 10 lines.
      for (var i = 0; i < 10; i++) {
        line.contextGroup.lines.push('lorem upsum');
      }

      // Does not include +10 buttons when there are fewer than 11 lines.
      var td = builder._createContextControl(section, line);
      var buttons = td.querySelectorAll('gr-button.showContext');

      assert.equal(buttons.length, 1);
      assert.equal(buttons[0].textContent, 'Show 10 common lines');

      // Add another line.
      line.contextGroup.lines.push('lorem upsum');

      // Includes +10 buttons when there are at least 11 lines.
      td = builder._createContextControl(section, line);
      buttons = td.querySelectorAll('gr-button.showContext');

      assert.equal(buttons.length, 3);
      assert.equal(buttons[0].textContent, '+10↑');
      assert.equal(buttons[1].textContent, 'Show 11 common lines');
      assert.equal(buttons[2].textContent, '+10↓');
    });

    test('newlines', function() {
      var text = 'abcdef';
      assert.equal(builder._addNewlines(text, text), text);
      text = 'a'.repeat(20);
      assert.equal(builder._addNewlines(text, text),
          'a'.repeat(10) +
          GrDiffBuilder.LINE_FEED_HTML +
          'a'.repeat(10));

      text = '<span class="thumbsup">👍</span>';
      var html = '&lt;span class=&quot;thumbsup&quot;&gt;👍&lt;&#x2F;span&gt;';
      assert.equal(builder._addNewlines(text, html),
          '&lt;span clas' +
          GrDiffBuilder.LINE_FEED_HTML +
          's=&quot;thumbsu' +
          GrDiffBuilder.LINE_FEED_HTML +
          'p&quot;&gt;👍&lt;&#x2F;spa' +
          GrDiffBuilder.LINE_FEED_HTML +
          'n&gt;');

      text = '01234\t56789';
      assert.equal(builder._addNewlines(text, text),
          '01234\t5' +
          GrDiffBuilder.LINE_FEED_HTML +
          '6789');
    });

    test('_addNewlines not called if line_wrapping is true', function(done) {
      builder._prefs = {line_wrapping: true, tab_size: 4, line_length: 50};
      var text = (new Array(52)).join('a');

      var line = {text: text, highlights: []};
      var newLineStub = sinon.stub(builder, '_addNewlines');
      builder._createTextEl(line);
      flush(function() {
        assert.isFalse(newLineStub.called);
        newLineStub.restore();
        done();
      });
    });

    test('_addNewlines called if line_wrapping is true and meets other ' +
        'conditions', function(done) {
      builder._prefs = {line_wrapping: false, tab_size: 4, line_length: 50};
      var text = (new Array(52)).join('a');

      var line = {text: text, highlights: []};
      var newLineStub = sinon.stub(builder, '_addNewlines');
      builder._createTextEl(line);

      flush(function() {
        assert.isTrue(newLineStub.called);
        newLineStub.restore();
        done();
      });
    });

    test('text length with tabs and unicode', function() {
      assert.equal(builder._textLength('12345', 4), 5);
      assert.equal(builder._textLength('\t\t12', 4), 10);
      assert.equal(builder._textLength('abc💢123', 4), 7);

      assert.equal(builder._textLength('abc\t', 8), 8);
      assert.equal(builder._textLength('abc\t\t', 10), 20);
      assert.equal(builder._textLength('', 10), 0);
      assert.equal(builder._textLength('', 10), 0);
      assert.equal(builder._textLength('abc\tde', 10), 12);
      assert.equal(builder._textLength('abc\tde\t', 10), 20);
      assert.equal(builder._textLength('\t\t\t\t\t', 20), 100);
    });

    test('tab wrapper insertion', function() {
      var html = 'abc\tdef';
      var wrapper = builder._getTabWrapper(
          builder._prefs.tab_size - 3,
          builder._prefs.show_tabs);
      assert.ok(wrapper);
      assert.isAbove(wrapper.length, 0);
      assert.equal(builder._addTabWrappers(html, builder._prefs.tab_size),
          'abc' + wrapper + 'def');
      assert.throws(builder._getTabWrapper.bind(
          builder,
          // using \x3c instead of < in string so gjslint can parse
          '">\x3cimg src="/" onerror="alert(1);">\x3cspan class="',
          true));
    });

    test('comments', function() {
      var line = new GrDiffLine(GrDiffLine.Type.BOTH);
      line.beforeNumber = 3;
      line.afterNumber = 5;

      var comments = {left: [], right: []};
      assert.deepEqual(builder._getCommentsForLine(comments, line), []);
      assert.deepEqual(builder._getCommentsForLine(comments, line,
          GrDiffBuilder.Side.LEFT), []);
      assert.deepEqual(builder._getCommentsForLine(comments, line,
          GrDiffBuilder.Side.RIGHT), []);

      comments = {
        left: [
          {id: 'l3', line: 3},
          {id: 'l5', line: 5},
        ],
        right: [
          {id: 'r3', line: 3},
          {id: 'r5', line: 5},
        ],
      };
      assert.deepEqual(builder._getCommentsForLine(comments, line),
          [{id: 'l3', line: 3}, {id: 'r5', line: 5}]);
      assert.deepEqual(builder._getCommentsForLine(comments, line,
          GrDiffBuilder.Side.LEFT), [{id: 'l3', line: 3}]);
      assert.deepEqual(builder._getCommentsForLine(comments, line,
          GrDiffBuilder.Side.RIGHT), [{id: 'r5', line: 5}]);
    });

    test('comment thread creation', function() {
      var l3 = {id: 'l3', line: 3, updated: '2016-08-09 00:42:32.000000000'};
      var l5 = {id: 'l5', line: 5, updated: '2016-08-09 00:42:32.000000000'};
      var r5 = {id: 'r5', line: 5, updated: '2016-08-09 00:42:32.000000000'};

      builder._comments = {
        meta: {
          changeNum: '42',
          patchRange: {
            basePatchNum: 'PARENT',
            patchNum: '3',
          },
          path: '/path/to/foo',
          projectConfig: {foo: 'bar'},
        },
        left: [l3, l5],
        right: [r5],
      };

      function checkThreadProps(threadEl, patchNum, side, comments) {
        assert.equal(threadEl.changeNum, '42');
        assert.equal(threadEl.patchNum, patchNum);
        assert.equal(threadEl.path, '/path/to/foo');
        assert.equal(threadEl.side, side);
        assert.deepEqual(threadEl.projectConfig, {foo: 'bar'});
        assert.deepEqual(threadEl.comments, comments);
      }

      var line = new GrDiffLine(GrDiffLine.Type.BOTH);
      line.beforeNumber = 5;
      line.afterNumber = 5;
      var threadEl = builder._commentThreadForLine(line);
      checkThreadProps(threadEl, '3', 'REVISION', [l5, r5]);

      threadEl = builder._commentThreadForLine(line, GrDiffBuilder.Side.RIGHT);
      checkThreadProps(threadEl, '3', 'REVISION', [r5]);

      threadEl = builder._commentThreadForLine(line, GrDiffBuilder.Side.LEFT);
      checkThreadProps(threadEl, '3', 'PARENT', [l5]);

      builder._comments.meta.patchRange.basePatchNum = '1';

      threadEl = builder._commentThreadForLine(line);
      checkThreadProps(threadEl, '3', 'REVISION', [l5, r5]);

      threadEl = builder._commentThreadForLine(line, GrDiffBuilder.Side.LEFT);
      checkThreadProps(threadEl, '1', 'REVISION', [l5]);

      threadEl = builder._commentThreadForLine(line, GrDiffBuilder.Side.RIGHT);
      checkThreadProps(threadEl, '3', 'REVISION', [r5]);

      builder._comments.meta.patchRange.basePatchNum = 'PARENT';

      line = new GrDiffLine(GrDiffLine.Type.REMOVE);
      line.beforeNumber = 5;
      line.afterNumber = 5;
      threadEl = builder._commentThreadForLine(line);
      checkThreadProps(threadEl, '3', 'PARENT', [l5, r5]);

      line = new GrDiffLine(GrDiffLine.Type.ADD);
      line.beforeNumber = 3;
      line.afterNumber = 5;
      threadEl = builder._commentThreadForLine(line);
      checkThreadProps(threadEl, '3', 'REVISION', [l3, r5]);
    });

    suite('intraline differences', function() {
      var el;
      var str;
      var annotateElementSpy;
      var layer;

      function slice(str, start, end) {
        return Array.from(str).slice(start, end).join('');
      }

      setup(function() {
        el = fixture('div-with-text');
        str = el.textContent;
        annotateElementSpy = sinon.spy(GrAnnotation, 'annotateElement');
        layer = document.createElement('gr-diff-builder')
            ._createIntralineLayer();
      });

      teardown(function() {
        annotateElementSpy.restore();
      });

      test('annotate no highlights', function() {
        var line = {
          text: str,
          highlights: [],
        };

        layer.annotate(el, line);

        // The content is unchanged.
        assert.isFalse(annotateElementSpy.called);
        assert.equal(el.childNodes.length, 1);
        assert.instanceOf(el.childNodes[0], Text);
        assert.equal(str, el.childNodes[0].textContent);
      });

      test('annotate with highlights', function() {
        var line = {
          text: str,
          highlights: [
            {startIndex: 6, endIndex: 12},
            {startIndex: 18, endIndex: 22},
          ],
        };
        var str0 = slice(str, 0, 6);
        var str1 = slice(str, 6, 12);
        var str2 = slice(str, 12, 18);
        var str3 = slice(str, 18, 22);
        var str4 = slice(str, 22);

        layer.annotate(el, line);

        assert.isTrue(annotateElementSpy.called);
        assert.equal(el.childNodes.length, 5);

        assert.instanceOf(el.childNodes[0], Text);
        assert.equal(el.childNodes[0].textContent, str0);

        assert.notInstanceOf(el.childNodes[1], Text);
        assert.equal(el.childNodes[1].textContent, str1);

        assert.instanceOf(el.childNodes[2], Text);
        assert.equal(el.childNodes[2].textContent, str2);

        assert.notInstanceOf(el.childNodes[3], Text);
        assert.equal(el.childNodes[3].textContent, str3);

        assert.instanceOf(el.childNodes[4], Text);
        assert.equal(el.childNodes[4].textContent, str4);
      });

      test('annotate without endIndex', function() {
        var line = {
          text: str,
          highlights: [
            {startIndex: 28},
          ],
        };

        var str0 = slice(str, 0, 28);
        var str1 = slice(str, 28);

        layer.annotate(el, line);

        assert.isTrue(annotateElementSpy.called);
        assert.equal(el.childNodes.length, 2);

        assert.instanceOf(el.childNodes[0], Text);
        assert.equal(el.childNodes[0].textContent, str0);

        assert.notInstanceOf(el.childNodes[1], Text);
        assert.equal(el.childNodes[1].textContent, str1);
      });

      test('annotate ignores empty highlights', function() {
        var line = {
          text: str,
          highlights: [
            {startIndex: 28, endIndex: 28},
          ],
        };

        layer.annotate(el, line);

        assert.isFalse(annotateElementSpy.called);
        assert.equal(el.childNodes.length, 1);
      });

      test('annotate handles unicode', function() {
        // Put some unicode into the string:
        str = str.replace(/\s/g, '💢');
        el.textContent = str;
        var line = {
          text: str,
          highlights: [
            {startIndex: 6, endIndex: 12},
          ],
        };

        var str0 = slice(str, 0, 6);
        var str1 = slice(str, 6, 12);
        var str2 = slice(str, 12);

        layer.annotate(el, line);

        assert.isTrue(annotateElementSpy.called);
        assert.equal(el.childNodes.length, 3);

        assert.instanceOf(el.childNodes[0], Text);
        assert.equal(el.childNodes[0].textContent, str0);

        assert.notInstanceOf(el.childNodes[1], Text);
        assert.equal(el.childNodes[1].textContent, str1);

        assert.instanceOf(el.childNodes[2], Text);
        assert.equal(el.childNodes[2].textContent, str2);
      });

      test('annotate handles unicode w/o endIndex', function() {
        // Put some unicode into the string:
        str = str.replace(/\s/g, '💢');
        el.textContent = str;

        var line = {
          text: str,
          highlights: [
            {startIndex: 6},
          ],
        };

        var str0 = slice(str, 0, 6);
        var str1 = slice(str, 6);

        layer.annotate(el, line);

        assert.isTrue(annotateElementSpy.called);
        assert.equal(el.childNodes.length, 2);

        assert.instanceOf(el.childNodes[0], Text);
        assert.equal(el.childNodes[0].textContent, str0);

        assert.notInstanceOf(el.childNodes[1], Text);
        assert.equal(el.childNodes[1].textContent, str1);
      });
    });

    suite('tab indicators', function() {
      var sandbox;
      var element;
      var layer;

      setup(function() {
        sandbox = sinon.sandbox.create();
        element = fixture('basic');
        element._showTabs = true;
        layer = element._createTabIndicatorLayer();
      });

      teardown(function() {
        sandbox.restore();
      });

      test('does nothing with empty line', function() {
        var line = {text: ''};
        var el = document.createElement('div');
        var annotateElementStub = sandbox.stub(GrAnnotation, 'annotateElement');

        layer.annotate(el, line);

        assert.isFalse(annotateElementStub.called);
      });

      test('does nothing with no tabs', function() {
        var str = 'lorem ipsum no tabs';
        var line = {text: str};
        var el = document.createElement('div');
        el.textContent = str;
        var annotateElementStub = sandbox.stub(GrAnnotation, 'annotateElement');

        layer.annotate(el, line);

        assert.isFalse(annotateElementStub.called);
      });

      test('annotates tab at beginning', function() {
        var str = '\tlorem upsum';
        var line = {text: str};
        var el = document.createElement('div');
        el.textContent = str;
        var annotateElementStub = sandbox.stub(GrAnnotation, 'annotateElement');

        layer.annotate(el, line);

        assert.equal(annotateElementStub.callCount, 1);
        var args = annotateElementStub.getCalls()[0].args;
        assert.equal(args[0], el);
        assert.equal(args[1], 0, 'offset of tab indicator');
        assert.equal(args[2], 1, 'length of tab indicator');
        assert.include(args[3], 'tab-indicator');
      });

      test('does not annotate when disabled', function() {
        element._showTabs = false;

        var str = '\tlorem upsum';
        var line = {text: str};
        var el = document.createElement('div');
        el.textContent = str;
        var annotateElementStub = sandbox.stub(GrAnnotation, 'annotateElement');

        layer.annotate(el, line);

        assert.isFalse(annotateElementStub.called);
      });

      test('annotates multiple in beginning', function() {
        var str = '\t\tlorem upsum';
        var line = {text: str};
        var el = document.createElement('div');
        el.textContent = str;
        var annotateElementStub = sandbox.stub(GrAnnotation, 'annotateElement');

        layer.annotate(el, line);

        assert.equal(annotateElementStub.callCount, 2);

        var args = annotateElementStub.getCalls()[0].args;
        assert.equal(args[0], el);
        assert.equal(args[1], 0, 'offset of tab indicator');
        assert.equal(args[2], 1, 'length of tab indicator');
        assert.include(args[3], 'tab-indicator');

        args = annotateElementStub.getCalls()[1].args;
        assert.equal(args[0], el);
        assert.equal(args[1], 1, 'offset of tab indicator');
        assert.equal(args[2], 1, 'length of tab indicator');
        assert.include(args[3], 'tab-indicator');
      });

      test('annotates intermediate tabs', function() {
        var str = 'lorem\tupsum';
        var line = {text: str};
        var el = document.createElement('div');
        el.textContent = str;
        var annotateElementStub = sandbox.stub(GrAnnotation, 'annotateElement');

        layer.annotate(el, line);

        assert.equal(annotateElementStub.callCount, 1);
        var args = annotateElementStub.getCalls()[0].args;
        assert.equal(args[0], el);
        assert.equal(args[1], 5, 'offset of tab indicator');
        assert.equal(args[2], 1, 'length of tab indicator');
        assert.include(args[3], 'tab-indicator');
      });
    });

    suite('rendering', function() {
      var content;
      var outputEl;
      var sandbox;

      setup(function(done) {
        sandbox = sinon.sandbox.create();
        var prefs = {
          line_length: 10,
          show_tabs: true,
          tab_size: 4,
          context: -1,
          syntax_highlighting: true,
        };
        content = [
          {
            a: ['all work and no play make andybons a dull boy'],
            b: ['elgoog elgoog elgoog']
          },
          {
            ab: [
              'Non eram nescius, Brute, cum, quae summis ingeniis ',
              'exquisitaque doctrina philosophi Graeco sermone tractavissent',
            ]
          },
        ];
        stub('gr-reporting', {
          time: sandbox.stub(),
          timeEnd: sandbox.stub(),
        });
        element = fixture('basic');
        outputEl = element.queryEffectiveChildren('#diffTable');
        sandbox.stub(element, '_getDiffBuilder', function() {
          var builder = new GrDiffBuilder(
              {content: content}, {left: [], right: []}, prefs, outputEl);
          sandbox.stub(builder, 'addColumns');
          builder.buildSectionElement = function(group) {
            var section = document.createElement('stub');
            section.textContent = group.lines.reduce(function(acc, line) {
              return acc + line.text;
            }, '');
            return section;
          };
          return builder;
        });
        element.diff = {content: content};
        element.render({left: [], right: []}, prefs).then(done);
      });

      teardown(function() {
        sandbox.restore();
      });

      test('reporting', function(done) {
        var timeStub = element.$.reporting.time;
        var timeEndStub = element.$.reporting.timeEnd;
        assert.isTrue(timeStub.calledWithExactly('Diff Total Render'));
        assert.isTrue(timeStub.calledWithExactly('Diff Content Render'));
        assert.isTrue(timeStub.calledWithExactly('Diff Syntax Render'));
        assert.isTrue(timeEndStub.calledWithExactly('Diff Total Render'));
        assert.isTrue(timeEndStub.calledWithExactly('Diff Content Render'));
        assert.isTrue(timeEndStub.calledWithExactly('Diff Syntax Render'));
        done();
      });

      test('renderSection', function() {
        var section = outputEl.querySelector('stub:nth-of-type(2)');
        var prevInnerHTML = section.innerHTML;
        section.innerHTML = 'wiped';
        element._builder.renderSection(section);
        section = outputEl.querySelector('stub:nth-of-type(2)');
        assert.equal(section.innerHTML, prevInnerHTML);
      });

      test('addColumns is called', function(done) {
        element.render({left: [], right: []}, {}).then(done);
        assert.isTrue(element._builder.addColumns.called);
      });

      test('getSectionsByLineRange one line', function() {
        var section = outputEl.querySelector('stub:nth-of-type(2)');
        var sections = element._builder.getSectionsByLineRange(1, 1, 'left');
        assert.equal(sections.length, 1);
        assert.strictEqual(sections[0], section);
      });

      test('getSectionsByLineRange over diff', function() {
        var section = [
          outputEl.querySelector('stub:nth-of-type(2)'),
          outputEl.querySelector('stub:nth-of-type(3)'),
        ];
        var sections = element._builder.getSectionsByLineRange(1, 2, 'left');
        assert.equal(sections.length, 2);
        assert.strictEqual(sections[0], section[0]);
        assert.strictEqual(sections[1], section[1]);
      });

      test('render-start and render are fired', function(done) {
        var fireStub = sinon.stub(element, 'fire');
        element.render({left: [], right: []}, {}).then(function() {
          assert.isTrue(fireStub.calledWithExactly('render-start'));
          assert.isTrue(fireStub.calledWithExactly('render'));
          done();
        });
      });

      test('rendering normal-sized diff does not disable syntax', function() {
        assert.isTrue(element.$.syntaxLayer.enabled);
      });

      test('rendering large diff disables syntax', function(done) {
        // Before it renders, set the first diff line to 500 '*' characters.
        element.diff.content[0].a = [new Array(501).join('*')];
        element.addEventListener('render', function() {
          assert.isFalse(element.$.syntaxLayer.enabled);
          done();
        });
        var prefs = {
          line_length: 10,
          show_tabs: true,
          tab_size: 4,
          context: -1,
          syntax_highlighting: true,
        };
        element.render({left: [], right: []}, prefs);
      });
    });

    suite('mock-diff', function() {
      var element;
      var builder;
      var diff;
      var prefs;

      setup(function(done) {
        element = fixture('mock-diff');
        diff = document.createElement('mock-diff-response').diffResponse;
        element.diff = diff;

        prefs = {
          line_length: 80,
          show_tabs: true,
          tab_size: 4,
        };

        element.render({left: [], right: []}, prefs).then(function() {
          builder = element._builder;
          done();
        });
      });

      test('getContentByLine', function() {
        var actual;

        actual = builder.getContentByLine(2, 'left');
        assert.equal(actual.textContent, diff.content[0].ab[1]);

        actual = builder.getContentByLine(2, 'right');
        assert.equal(actual.textContent, diff.content[0].ab[1]);

        actual = builder.getContentByLine(5, 'left');
        assert.equal(actual.textContent, diff.content[2].ab[0]);

        actual = builder.getContentByLine(5, 'right');
        assert.equal(actual.textContent, diff.content[1].b[0]);
      });

      test('findLinesByRange', function() {
        var lines = [];
        var elems = [];
        var start = 6;
        var end = 10;
        var count = end - start + 1;

        builder.findLinesByRange(start, end, 'right', lines, elems);

        assert.equal(lines.length, count);
        assert.equal(elems.length, count);

        for (var i = 0; i < 5; i++) {
          assert.instanceOf(lines[i], GrDiffLine);
          assert.equal(lines[i].afterNumber, start + i);
          assert.instanceOf(elems[i], HTMLElement);
          assert.equal(lines[i].text, elems[i].textContent);
        }
      });

      test('_renderContentByRange', function() {
        var spy = sinon.spy(builder, '_createTextEl');
        var start = 9;
        var end = 14;
        var count = end - start + 1;

        builder._renderContentByRange(start, end, 'left');

        assert.equal(spy.callCount, count);
        spy.getCalls().forEach(function(call, i) {
          assert.equal(call.args[0].beforeNumber, start + i);
        });

        spy.restore();
      });

      test('_getNextContentOnSide side-by-side left', function() {
        var startElem = builder.getContentByLine(5, 'left',
            element.$.diffTable);
        var expectedStartString = diff.content[2].ab[0];
        var expectedNextString = diff.content[2].ab[1];
        assert.equal(startElem.textContent, expectedStartString);

        var nextElem = builder._getNextContentOnSide(startElem,
            'left');
        assert.equal(nextElem.textContent, expectedNextString);
      });

      test('_getNextContentOnSide side-by-side right', function() {
        var startElem = builder.getContentByLine(5, 'right',
            element.$.diffTable);
        var expectedStartString = diff.content[1].b[0];
        var expectedNextString = diff.content[1].b[1];
        assert.equal(startElem.textContent, expectedStartString);

        var nextElem = builder._getNextContentOnSide(startElem,
            'right');
        assert.equal(nextElem.textContent, expectedNextString);
      });

      test('_getNextContentOnSide unified left', function(done) {
        // Re-render as unified:
        element.viewMode = 'UNIFIED_DIFF';
        element.render({left: [], right: []}, prefs).then(function() {
          builder = element._builder;

          var startElem = builder.getContentByLine(5, 'left',
              element.$.diffTable);
          var expectedStartString = diff.content[2].ab[0];
          var expectedNextString = diff.content[2].ab[1];
          assert.equal(startElem.textContent, expectedStartString);

          var nextElem = builder._getNextContentOnSide(startElem,
              'left');
          assert.equal(nextElem.textContent, expectedNextString);

          done();
        });
      });

      test('_getNextContentOnSide unified right', function(done) {
        // Re-render as unified:
        element.viewMode = 'UNIFIED_DIFF';
        element.render({left: [], right: []}, prefs).then(function() {
          builder = element._builder;

          var startElem = builder.getContentByLine(5, 'right',
              element.$.diffTable);
          var expectedStartString = diff.content[1].b[0];
          var expectedNextString = diff.content[1].b[1];
          assert.equal(startElem.textContent, expectedStartString);

          var nextElem = builder._getNextContentOnSide(startElem,
              'right');
          assert.equal(nextElem.textContent, expectedNextString);

          done();
        });
      });
    });
  });
</script>