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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</title>
<script src="/test/common-test-setup.js"></script>
<script src="/bower_components/webcomponentsjs/custom-elements-es5-adapter.js"></script>

<script src="/bower_components/webcomponentsjs/webcomponents-lite.js"></script>
<script src="/bower_components/web-component-tester/browser.js"></script>
<link rel="import" href="../../../test/common-test-setup.html"/>
<script src="../../../scripts/util.js"></script>

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

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

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

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

    const MINIMAL_PREFS = {tab_size: 2, line_length: 80};

    setup(() => {
      sandbox = sinon.sandbox.create();
    });

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

    suite('selectionchange event handling', () => {
      const emulateSelection = function() {
        document.dispatchEvent(new CustomEvent('selectionchange'));
      };

      setup(() => {
        element = fixture('basic');
        sandbox.stub(element.$.highlights, 'handleSelectionChange');
      });

      test('enabled if logged in', () => {
        element.loggedIn = true;
        emulateSelection();
        assert.isTrue(element.$.highlights.handleSelectionChange.called);
      });

      test('ignored if logged out', () => {
        element.loggedIn = false;
        emulateSelection();
        assert.isFalse(element.$.highlights.handleSelectionChange.called);
      });
    });


    test('cancel', () => {
      element = fixture('basic');
      const cancelStub = sandbox.stub(element.$.diffBuilder, 'cancel');
      element.cancel();
      assert.isTrue(cancelStub.calledOnce);
    });

    test('line limit with line_wrapping', () => {
      element = fixture('basic');
      element.prefs = Object.assign({}, MINIMAL_PREFS, {line_wrapping: true});
      flushAsynchronousOperations();
      assert.equal(util.getComputedStyleValue('--line-limit', element), '80ch');
    });

    test('line limit without line_wrapping', () => {
      element = fixture('basic');
      element.prefs = Object.assign({}, MINIMAL_PREFS, {line_wrapping: false});
      flushAsynchronousOperations();
      assert.isNotOk(util.getComputedStyleValue('--line-limit', element));
    });

    suite('_get{PatchNum|IsParentComment}ByLineAndContent', () => {
      let lineEl;
      let contentEl;

      setup(() => {
        element = fixture('basic');
        lineEl = document.createElement('td');
        contentEl = document.createElement('span');
      });

      suite('_getPatchNumByLineAndContent', () => {
        test('right side', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 'PARENT'};
          lineEl.classList.add('right');
          assert.equal(element._getPatchNumByLineAndContent(lineEl, contentEl),
              4);
        });

        test('left side parent by linenum', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 'PARENT'};
          lineEl.classList.add('left');
          assert.equal(element._getPatchNumByLineAndContent(lineEl, contentEl),
              4);
        });

        test('left side parent by content', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 'PARENT'};
          contentEl.classList.add('remove');
          assert.equal(element._getPatchNumByLineAndContent(lineEl, contentEl),
              4);
        });

        test('left side merge parent', () => {
          element.patchRange = {patchNum: 4, basePatchNum: -2};
          contentEl.classList.add('remove');
          assert.equal(element._getPatchNumByLineAndContent(lineEl, contentEl),
              4);
        });

        test('left side non parent', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 3};
          contentEl.classList.add('remove');
          assert.equal(element._getPatchNumByLineAndContent(lineEl, contentEl),
              3);
        });
      });

      suite('_getIsParentCommentByLineAndContent', () => {
        test('right side', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 'PARENT'};
          lineEl.classList.add('right');
          assert.isFalse(
              element._getIsParentCommentByLineAndContent(lineEl, contentEl));
        });

        test('left side parent by linenum', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 'PARENT'};
          lineEl.classList.add('left');
          assert.isTrue(
              element._getIsParentCommentByLineAndContent(lineEl, contentEl));
        });

        test('left side parent by content', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 'PARENT'};
          contentEl.classList.add('remove');
          assert.isTrue(
              element._getIsParentCommentByLineAndContent(lineEl, contentEl));
        });

        test('left side merge parent', () => {
          element.patchRange = {patchNum: 4, basePatchNum: -2};
          contentEl.classList.add('remove');
          assert.isTrue(
              element._getIsParentCommentByLineAndContent(lineEl, contentEl));
        });

        test('left side non parent', () => {
          element.patchRange = {patchNum: 4, basePatchNum: 3};
          contentEl.classList.add('remove');
          assert.isFalse(
              element._getIsParentCommentByLineAndContent(lineEl, contentEl));
        });
      });
    });

    suite('not logged in', () => {
      setup(() => {
        const getLoggedInPromise = Promise.resolve(false);
        stub('gr-rest-api-interface', {
          getLoggedIn() { return getLoggedInPromise; },
        });
        element = fixture('basic');
        return getLoggedInPromise;
      });

      test('toggleLeftDiff', () => {
        element.toggleLeftDiff();
        assert.isTrue(element.classList.contains('no-left'));
        element.toggleLeftDiff();
        assert.isFalse(element.classList.contains('no-left'));
      });

      test('addDraftAtLine', () => {
        sandbox.stub(element, '_selectLine');
        const loggedInErrorSpy = sandbox.spy();
        element.addEventListener('show-auth-required', loggedInErrorSpy);
        element.addDraftAtLine();
        assert.isTrue(loggedInErrorSpy.called);
      });

      test('view does not start with displayLine classList', () => {
        assert.isFalse(
            element.$$('.diffContainer').classList.contains('displayLine'));
      });

      test('displayLine class added called when displayLine is true', () => {
        const spy = sandbox.spy(element, '_computeContainerClass');
        element.displayLine = true;
        assert.isTrue(spy.called);
        assert.isTrue(
            element.$$('.diffContainer').classList.contains('displayLine'));
      });

      test('thread groups', () => {
        const contentEl = document.createElement('div');

        element.changeNum = 123;
        element.patchRange = {basePatchNum: 1, patchNum: 2};
        element.path = 'file.txt';

        const mock = document.createElement('mock-diff-response');
        element.$.diffBuilder._builder = element.$.diffBuilder._getDiffBuilder(
            mock.diffResponse, Object.assign({}, MINIMAL_PREFS));

        // No thread groups.
        assert.isNotOk(element._getThreadGroupForLine(contentEl));

        // A thread group gets created.
        const threadGroupEl = element._getOrCreateThreadGroup(contentEl);
        assert.isOk(threadGroupEl);

        // The new thread group can be fetched.
        assert.isOk(element._getThreadGroupForLine(contentEl));

        assert.equal(contentEl.querySelectorAll('.thread-group').length, 1);
      });

      suite('image diffs', () => {
        let mockFile1;
        let mockFile2;
        setup(() => {
          mockFile1 = {
            body: 'Qk06AAAAAAAAADYAAAAoAAAAAQAAAP////8BACAAAAAAAAAAAAATCwAAE' +
            'wsAAAAAAAAAAAAAAAAA/w==',
            type: 'image/bmp',
          };
          mockFile2 = {
            body: 'Qk06AAAAAAAAADYAAAAoAAAAAQAAAP////8BACAAAAAAAAAAAAATCwAAE' +
            'wsAAAAAAAAAAAAA/////w==',
            type: 'image/bmp',
          };

          element.patchRange = {basePatchNum: 'PARENT', patchNum: 1};
          element.isImageDiff = true;
          element.prefs = {
            auto_hide_diff_table_header: true,
            context: 10,
            cursor_blink_rate: 0,
            font_size: 12,
            ignore_whitespace: 'IGNORE_NONE',
            intraline_difference: true,
            line_length: 100,
            line_wrapping: false,
            show_line_endings: true,
            show_tabs: true,
            show_whitespace_errors: true,
            syntax_highlighting: true,
            tab_size: 8,
            theme: 'DEFAULT',
          };
        });

        test('renders image diffs with same file name', done => {
          const rendered = () => {
            // Recognizes that it should be an image diff.
            assert.isTrue(element.isImageDiff);
            assert.instanceOf(
                element.$.diffBuilder._builder, GrDiffBuilderImage);

            // Left image rendered with the parent commit's version of the file.
            const leftImage = element.$.diffTable.querySelector('td.left img');
            const leftLabel =
                element.$.diffTable.querySelector('td.left label');
            const leftLabelContent = leftLabel.querySelector('.label');
            const leftLabelName = leftLabel.querySelector('.name');

            const rightImage =
                element.$.diffTable.querySelector('td.right img');
            const rightLabel = element.$.diffTable.querySelector(
                'td.right label');
            const rightLabelContent = rightLabel.querySelector('.label');
            const rightLabelName = rightLabel.querySelector('.name');

            assert.isNotOk(rightLabelName);
            assert.isNotOk(leftLabelName);

            let leftLoaded = false;
            let rightLoaded = false;

            leftImage.addEventListener('load', () => {
              assert.isOk(leftImage);
              assert.equal(leftImage.getAttribute('src'),
                  'data:image/bmp;base64, ' + mockFile1.body);
              assert.equal(leftLabelContent.textContent, '1×1 image/bmp');
              leftLoaded = true;
              if (rightLoaded) {
                element.removeEventListener('render', rendered);
                done();
              }
            });

            rightImage.addEventListener('load', () => {
              assert.isOk(rightImage);
              assert.equal(rightImage.getAttribute('src'),
                  'data:image/bmp;base64, ' + mockFile2.body);
              assert.equal(rightLabelContent.textContent, '1×1 image/bmp');

              rightLoaded = true;
              if (leftLoaded) {
                element.removeEventListener('render', rendered);
                done();
              }
            });
          };

          element.addEventListener('render', rendered);

          element.baseImage = mockFile1;
          element.revisionImage = mockFile2;
          element.diff = {
            meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
            meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
              lines: 560},
            intraline_status: 'OK',
            change_type: 'MODIFIED',
            diff_header: [
              'diff --git a/carrot.jpg b/carrot.jpg',
              'index 2adc47d..f9c2f2c 100644',
              '--- a/carrot.jpg',
              '+++ b/carrot.jpg',
              'Binary files differ',
            ],
            content: [{skip: 66}],
            binary: true,
          };
        });

        test('renders image diffs with a different file name', done => {
          const mockDiff = {
            meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
            meta_b: {name: 'carrot2.jpg', content_type: 'image/jpeg',
              lines: 560},
            intraline_status: 'OK',
            change_type: 'MODIFIED',
            diff_header: [
              'diff --git a/carrot.jpg b/carrot2.jpg',
              'index 2adc47d..f9c2f2c 100644',
              '--- a/carrot.jpg',
              '+++ b/carrot2.jpg',
              'Binary files differ',
            ],
            content: [{skip: 66}],
            binary: true,
          };

          const rendered = () => {
            // Recognizes that it should be an image diff.
            assert.isTrue(element.isImageDiff);
            assert.instanceOf(
                element.$.diffBuilder._builder, GrDiffBuilderImage);

            // Left image rendered with the parent commit's version of the file.
            const leftImage = element.$.diffTable.querySelector('td.left img');
            const leftLabel =
                element.$.diffTable.querySelector('td.left label');
            const leftLabelContent = leftLabel.querySelector('.label');
            const leftLabelName = leftLabel.querySelector('.name');

            const rightImage =
                element.$.diffTable.querySelector('td.right img');
            const rightLabel = element.$.diffTable.querySelector(
                'td.right label');
            const rightLabelContent = rightLabel.querySelector('.label');
            const rightLabelName = rightLabel.querySelector('.name');

            assert.isOk(rightLabelName);
            assert.isOk(leftLabelName);
            assert.equal(leftLabelName.textContent, mockDiff.meta_a.name);
            assert.equal(rightLabelName.textContent, mockDiff.meta_b.name);

            let leftLoaded = false;
            let rightLoaded = false;

            leftImage.addEventListener('load', () => {
              assert.isOk(leftImage);
              assert.equal(leftImage.getAttribute('src'),
                  'data:image/bmp;base64, ' + mockFile1.body);
              assert.equal(leftLabelContent.textContent, '1×1 image/bmp');
              leftLoaded = true;
              if (rightLoaded) {
                element.removeEventListener('render', rendered);
                done();
              }
            });

            rightImage.addEventListener('load', () => {
              assert.isOk(rightImage);
              assert.equal(rightImage.getAttribute('src'),
                  'data:image/bmp;base64, ' + mockFile2.body);
              assert.equal(rightLabelContent.textContent, '1×1 image/bmp');

              rightLoaded = true;
              if (leftLoaded) {
                element.removeEventListener('render', rendered);
                done();
              }
            });
          };

          element.addEventListener('render', rendered);

          element.baseImage = mockFile1;
          element.baseImage._name = mockDiff.meta_a.name;
          element.revisionImage = mockFile2;
          element.revisionImage._name = mockDiff.meta_b.name;
          element.diff = mockDiff;
        });

        test('renders added image', done => {
          const mockDiff = {
            meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
              lines: 560},
            intraline_status: 'OK',
            change_type: 'ADDED',
            diff_header: [
              'diff --git a/carrot.jpg b/carrot.jpg',
              'index 0000000..f9c2f2c 100644',
              '--- /dev/null',
              '+++ b/carrot.jpg',
              'Binary files differ',
            ],
            content: [{skip: 66}],
            binary: true,
          };

          function rendered() {
            // Recognizes that it should be an image diff.
            assert.isTrue(element.isImageDiff);
            assert.instanceOf(
                element.$.diffBuilder._builder, GrDiffBuilderImage);

            const leftImage = element.$.diffTable.querySelector('td.left img');
            const rightImage = element.$.diffTable.querySelector('td.right img');

            assert.isNotOk(leftImage);
            assert.isOk(rightImage);
            done();
            element.removeEventListener('render', rendered);
          }
          element.addEventListener('render', rendered);

          element.revisionImage = mockFile2;
          element.diff = mockDiff;
        });

        test('renders removed image', done => {
          const mockDiff = {
            meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg',
              lines: 560},
            intraline_status: 'OK',
            change_type: 'DELETED',
            diff_header: [
              'diff --git a/carrot.jpg b/carrot.jpg',
              'index f9c2f2c..0000000 100644',
              '--- a/carrot.jpg',
              '+++ /dev/null',
              'Binary files differ',
            ],
            content: [{skip: 66}],
            binary: true,
          };

          function rendered() {
            // Recognizes that it should be an image diff.
            assert.isTrue(element.isImageDiff);
            assert.instanceOf(
                element.$.diffBuilder._builder, GrDiffBuilderImage);

            const leftImage = element.$.diffTable.querySelector('td.left img');
            const rightImage = element.$.diffTable.querySelector('td.right img');

            assert.isOk(leftImage);
            assert.isNotOk(rightImage);
            done();
            element.removeEventListener('render', rendered);
          }
          element.addEventListener('render', rendered);

          element.baseImage = mockFile1;
          element.diff = mockDiff;
        });

        test('does not render disallowed image type', done => {
          const mockDiff = {
            meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg-evil',
              lines: 560},
            intraline_status: 'OK',
            change_type: 'DELETED',
            diff_header: [
              'diff --git a/carrot.jpg b/carrot.jpg',
              'index f9c2f2c..0000000 100644',
              '--- a/carrot.jpg',
              '+++ /dev/null',
              'Binary files differ',
            ],
            content: [{skip: 66}],
            binary: true,
          };
          mockFile1.type = 'image/jpeg-evil';

          function rendered() {
            // Recognizes that it should be an image diff.
            assert.isTrue(element.isImageDiff);
            assert.instanceOf(
                element.$.diffBuilder._builder, GrDiffBuilderImage);
            const leftImage = element.$.diffTable.querySelector('td.left img');
            assert.isNotOk(leftImage);
            done();
            element.removeEventListener('render', rendered);
          }
          element.addEventListener('render', rendered);

          element.baseImage = mockFile1;
          element.diff = mockDiff;
        });
      });

      test('_handleTap lineNum', done => {
        const addDraftStub = sandbox.stub(element, 'addDraftAtLine');
        const el = document.createElement('div');
        el.className = 'lineNum';
        el.addEventListener('click', e => {
          element._handleTap(e);
          assert.isTrue(addDraftStub.called);
          assert.equal(addDraftStub.lastCall.args[0], el);
          done();
        });
        el.click();
      });

      test('_handleTap context', done => {
        const showContextStub =
            sandbox.stub(element.$.diffBuilder, 'showContext');
        const el = document.createElement('div');
        el.className = 'showContext';
        el.addEventListener('click', e => {
          element._handleTap(e);
          assert.isTrue(showContextStub.called);
          done();
        });
        el.click();
      });

      test('_handleTap content', done => {
        const content = document.createElement('div');
        const lineEl = document.createElement('div');

        const selectStub = sandbox.stub(element, '_selectLine');
        sandbox.stub(element.$.diffBuilder, 'getLineElByChild', () => lineEl);

        content.className = 'content';
        content.addEventListener('click', e => {
          element._handleTap(e);
          assert.isTrue(selectStub.called);
          assert.equal(selectStub.lastCall.args[0], lineEl);
          done();
        });
        content.click();
      });

      suite('getCursorStops', () => {
        const setupDiff = function() {
          const mock = document.createElement('mock-diff-response');
          element.diff = mock.diffResponse;
          element.prefs = {
            context: 10,
            tab_size: 8,
            font_size: 12,
            line_length: 100,
            cursor_blink_rate: 0,
            line_wrapping: false,
            intraline_difference: true,
            show_line_endings: true,
            show_tabs: true,
            show_whitespace_errors: true,
            syntax_highlighting: true,
            auto_hide_diff_table_header: true,
            theme: 'DEFAULT',
            ignore_whitespace: 'IGNORE_NONE',
          };

          element._renderDiffTable();
          flushAsynchronousOperations();
        };

        test('getCursorStops returns [] when hidden and noAutoRender', () => {
          element.noAutoRender = true;
          setupDiff();
          element.hidden = true;
          assert.equal(element.getCursorStops().length, 0);
        });

        test('getCursorStops', () => {
          setupDiff();
          assert.equal(element.getCursorStops().length, 50);
        });
      });

      test('adds .hiddenscroll', () => {
        Gerrit.hiddenscroll = true;
        element.displayLine = true;
        assert.include(element.$$('.diffContainer').className, 'hiddenscroll');
      });
    });

    suite('logged in', () => {
      let fakeLineEl;
      setup(() => {
        element = fixture('basic');
        element.loggedIn = true;
        element.patchRange = {};

        fakeLineEl = {
          getAttribute: sandbox.stub().returns(42),
          classList: {
            contains: sandbox.stub().returns(true),
          },
        };
      });

      test('addDraftAtLine', () => {
        sandbox.stub(element, '_selectLine');
        sandbox.stub(element, '_createComment');
        element.addDraftAtLine(fakeLineEl);
        assert.isTrue(element._createComment
            .calledWithExactly(fakeLineEl, 42));
      });

      test('addDraftAtLine on an edit', () => {
        element.patchRange.basePatchNum = element.EDIT_NAME;
        sandbox.stub(element, '_selectLine');
        sandbox.stub(element, '_createComment');
        const alertSpy = sandbox.spy();
        element.addEventListener('show-alert', alertSpy);
        element.addDraftAtLine(fakeLineEl);
        assert.isTrue(alertSpy.called);
        assert.isFalse(element._createComment.called);
      });

      test('addDraftAtLine on an edit base', () => {
        element.patchRange.patchNum = element.EDIT_NAME;
        element.patchRange.basePatchNum = element.PARENT_NAME;
        sandbox.stub(element, '_selectLine');
        sandbox.stub(element, '_createComment');
        const alertSpy = sandbox.spy();
        element.addEventListener('show-alert', alertSpy);
        element.addDraftAtLine(fakeLineEl);
        assert.isTrue(alertSpy.called);
        assert.isFalse(element._createComment.called);
      });

      suite('change in preferences', () => {
        setup(() => {
          element.diff = {
            meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
            meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
              lines: 560},
            diff_header: [],
            intraline_status: 'OK',
            change_type: 'MODIFIED',
            content: [{skip: 66}],
          };
          element.flushDebouncer('renderDiffTable');
        });

        test('change in preferences re-renders diff', () => {
          sandbox.stub(element, '_renderDiffTable');
          element.prefs = Object.assign(
              {}, MINIMAL_PREFS, {time_format: 'HHMM_12'});
          element.flushDebouncer('renderDiffTable');
          assert.isTrue(element._renderDiffTable.called);
        });

        test('adding/removing property in preferences re-renders diff', () => {
          const stub = sandbox.stub(element, '_renderDiffTable');
          const newPrefs1 = Object.assign({}, MINIMAL_PREFS,
              {line_wrapping: true});
          element.prefs = newPrefs1;
          element.flushDebouncer('renderDiffTable');
          assert.isTrue(element._renderDiffTable.called);
          stub.reset();

          const newPrefs2 = Object.assign({}, newPrefs1);
          delete newPrefs2.line_wrapping;
          element.prefs = newPrefs2;
          element.flushDebouncer('renderDiffTable');
          assert.isTrue(element._renderDiffTable.called);
        });

        test('change in preferences does not re-renders diff with ' +
            'noRenderOnPrefsChange', () => {
          sandbox.stub(element, '_renderDiffTable');
          element.noRenderOnPrefsChange = true;
          element.prefs = Object.assign(
              {}, MINIMAL_PREFS, {time_format: 'HHMM_12'});
          element.flushDebouncer('renderDiffTable');
          assert.isFalse(element._renderDiffTable.called);
        });
      });
    });

    suite('diff header', () => {
      setup(() => {
        element = fixture('basic');
        element.diff = {
          meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
          meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
            lines: 560},
          diff_header: [],
          intraline_status: 'OK',
          change_type: 'MODIFIED',
          content: [{skip: 66}],
        };
      });

      test('hidden', () => {
        assert.equal(element._diffHeaderItems.length, 0);
        element.push('diff.diff_header', 'diff --git a/test.jpg b/test.jpg');
        assert.equal(element._diffHeaderItems.length, 0);
        element.push('diff.diff_header', 'index 2adc47d..f9c2f2c 100644');
        assert.equal(element._diffHeaderItems.length, 0);
        element.push('diff.diff_header', '--- a/test.jpg');
        assert.equal(element._diffHeaderItems.length, 0);
        element.push('diff.diff_header', '+++ b/test.jpg');
        assert.equal(element._diffHeaderItems.length, 0);
        element.push('diff.diff_header', 'test');
        assert.equal(element._diffHeaderItems.length, 1);
        flushAsynchronousOperations();

        assert.equal(element.$.diffHeader.textContent.trim(), 'test');
      });

      test('binary files', () => {
        element.diff.binary = true;
        assert.equal(element._diffHeaderItems.length, 0);
        element.push('diff.diff_header', 'diff --git a/test.jpg b/test.jpg');
        assert.equal(element._diffHeaderItems.length, 0);
        element.push('diff.diff_header', 'test');
        assert.equal(element._diffHeaderItems.length, 1);
        element.push('diff.diff_header', 'Binary files differ');
        assert.equal(element._diffHeaderItems.length, 1);
      });
    });

    suite('safety and bypass', () => {
      let renderStub;

      setup(() => {
        element = fixture('basic');
        renderStub = sandbox.stub(element.$.diffBuilder, 'render',
            () => {
              element.$.diffBuilder.dispatchEvent(
                  new CustomEvent('render', {bubbles: true, composed: true}));
              return Promise.resolve({});
            });
        const mock = document.createElement('mock-diff-response');
        sandbox.stub(element, 'getDiffLength').returns(10000);
        element.diff = mock.diffResponse;
        element.noRenderOnPrefsChange = true;
      });

      test('large render w/ context = 10', done => {
        element.prefs = Object.assign({}, MINIMAL_PREFS, {context: 10});
        function rendered() {
          assert.isTrue(renderStub.called);
          assert.isFalse(element._showWarning);
          done();
          element.removeEventListener('render', rendered);
        }
        element.addEventListener('render', rendered);
        element._renderDiffTable();
      });

      test('large render w/ whole file and bypass', done => {
        element.prefs = Object.assign({}, MINIMAL_PREFS, {context: -1});
        element._safetyBypass = 10;
        function rendered() {
          assert.isTrue(renderStub.called);
          assert.isFalse(element._showWarning);
          done();
          element.removeEventListener('render', rendered);
        }
        element.addEventListener('render', rendered);
        element._renderDiffTable();
      });

      test('large render w/ whole file and no bypass', done => {
        element.prefs = Object.assign({}, MINIMAL_PREFS, {context: -1});
        function rendered() {
          assert.isFalse(renderStub.called);
          assert.isTrue(element._showWarning);
          done();
          element.removeEventListener('render', rendered);
        }
        element.addEventListener('render', rendered);
        element._renderDiffTable();
      });
    });

    suite('blame', () => {
      setup(() => {
        element = fixture('basic');
      });

      test('unsetting', () => {
        element.blame = [];
        const setBlameSpy = sandbox.spy(element.$.diffBuilder, 'setBlame');
        element.classList.add('showBlame');
        element.blame = null;
        assert.isTrue(setBlameSpy.calledWithExactly(null));
        assert.isFalse(element.classList.contains('showBlame'));
      });

      test('setting', () => {
        const mockBlame = [{id: 'commit id', ranges: [{start: 1, end: 2}]}];
        element.blame = mockBlame;
        assert.isTrue(element.classList.contains('showBlame'));
      });
    });

    suite('trailing newlines', () => {
      setup(() => {
        element = fixture('basic');
      });

      suite('_lastChunkForSide', () => {
        test('deltas', () => {
          const diff = {content: [
            {a: ['foo', 'bar'], b: ['baz']},
            {ab: ['foo', 'bar', 'baz']},
            {b: ['foo']},
          ]};
          assert.equal(element._lastChunkForSide(diff, false), diff.content[2]);
          assert.equal(element._lastChunkForSide(diff, true), diff.content[1]);

          diff.content.push({a: ['foo'], b: ['bar']});
          assert.equal(element._lastChunkForSide(diff, false), diff.content[3]);
          assert.equal(element._lastChunkForSide(diff, true), diff.content[3]);
        });

        test('addition with a undefined', () => {
          const diff = {content: [
            {b: ['foo', 'bar', 'baz']},
          ]};
          assert.equal(element._lastChunkForSide(diff, false), diff.content[0]);
          assert.isNull(element._lastChunkForSide(diff, true));
        });

        test('addition with a empty', () => {
          const diff = {content: [
            {a: [], b: ['foo', 'bar', 'baz']},
          ]};
          assert.equal(element._lastChunkForSide(diff, false), diff.content[0]);
          assert.isNull(element._lastChunkForSide(diff, true));
        });


        test('deletion with b undefined', () => {
          const diff = {content: [
            {a: ['foo', 'bar', 'baz']},
          ]};
          assert.isNull(element._lastChunkForSide(diff, false));
          assert.equal(element._lastChunkForSide(diff, true), diff.content[0]);
        });

        test('deletion with b empty', () => {
          const diff = {content: [
            {a: ['foo', 'bar', 'baz'], b: []},
          ]};
          assert.isNull(element._lastChunkForSide(diff, false));
          assert.equal(element._lastChunkForSide(diff, true), diff.content[0]);
        });

        test('empty', () => {
          const diff = {content: []};
          assert.isNull(element._lastChunkForSide(diff, false));
          assert.isNull(element._lastChunkForSide(diff, true));
        });
      });

      suite('_hasTrailingNewlines', () => {
        test('shared no trailing', () => {
          const diff = undefined;
          sandbox.stub(element, '_lastChunkForSide')
              .returns({ab: ['foo', 'bar']});
          assert.isFalse(element._hasTrailingNewlines(diff, false));
          assert.isFalse(element._hasTrailingNewlines(diff, true));
        });

        test('delta trailing in right', () => {
          const diff = undefined;
          sandbox.stub(element, '_lastChunkForSide')
              .returns({a: ['foo', 'bar'], b: ['baz', '']});
          assert.isTrue(element._hasTrailingNewlines(diff, false));
          assert.isFalse(element._hasTrailingNewlines(diff, true));
        });

        test('addition', () => {
          const diff = undefined;
          sandbox.stub(element, '_lastChunkForSide', (diff, leftSide) => {
            if (leftSide) { return null; }
            return {b: ['foo', '']};
          });
          assert.isTrue(element._hasTrailingNewlines(diff, false));
          assert.isNull(element._hasTrailingNewlines(diff, true));
        });

        test('deletion', () => {
          const diff = undefined;
          sandbox.stub(element, '_lastChunkForSide', (diff, leftSide) => {
            if (!leftSide) { return null; }
            return {a: ['foo']};
          });
          assert.isNull(element._hasTrailingNewlines(diff, false));
          assert.isFalse(element._hasTrailingNewlines(diff, true));
        });
      });

      test('_computeNewlineWarning', () => {
        const NO_NEWLINE_BASE = 'No newline at end of base file.';
        const NO_NEWLINE_REVISION = 'No newline at end of revision file.';

        let hasLeft;
        let hasRight;
        sandbox.stub(element, '_hasTrailingNewlines', (diff, left) => {
          if (left) { return hasLeft; }
          return hasRight;
        });
        const diff = undefined;

        // The revision has a trailing newline, but the base doesn't.
        hasLeft = true;
        hasRight = false;
        assert.equal(element._computeNewlineWarning(diff), NO_NEWLINE_REVISION);

        // Trailing newlines were undetermined in the revision.
        hasLeft = true;
        hasRight = null;
        assert.isNull(element._computeNewlineWarning(diff));

        // Missing trailing newlines in the base.
        hasLeft = false;
        hasRight = null;
        assert.equal(element._computeNewlineWarning(diff), NO_NEWLINE_BASE);

        // Missing trailing newlines in both.
        hasLeft = false;
        hasRight = false;
        assert.equal(element._computeNewlineWarning(diff),
            NO_NEWLINE_BASE + ' — ' + NO_NEWLINE_REVISION);
      });

      test('_computeNewlineWarningClass', () => {
        const hidden = 'newlineWarning hidden';
        const shown = 'newlineWarning';
        assert.equal(element._computeNewlineWarningClass(null, true), hidden);
        assert.equal(element._computeNewlineWarningClass('foo', true), hidden);
        assert.equal(element._computeNewlineWarningClass(null, false), hidden);
        assert.equal(element._computeNewlineWarningClass('foo', false), shown);
      });

      test('_prefsEqual', () => {
        element = fixture('basic');
        assert.isTrue(element._prefsEqual(null, null));
        assert.isTrue(element._prefsEqual({}, {}));
        assert.isTrue(element._prefsEqual({x: 1}, {x: 1}));
        assert.isTrue(
            element._prefsEqual({x: 1, abc: 'def'}, {x: 1, abc: 'def'}));
        const somePref = {abc: 'def', p: true};
        assert.isTrue(element._prefsEqual(somePref, somePref));

        assert.isFalse(element._prefsEqual({}, null));
        assert.isFalse(element._prefsEqual(null, {}));
        assert.isFalse(element._prefsEqual({x: 1}, {x: 2}));
        assert.isFalse(element._prefsEqual({x: 1, y: 'abc'}, {x: 1, y: 'abcd'}));
        assert.isFalse(element._prefsEqual({x: 1, y: 'abc'}, {x: 1}));
        assert.isFalse(element._prefsEqual({x: 1}, {x: 1, y: 'abc'}));
      });
    });

    suite('key locations', () => {
      let renderStub;

      setup(() => {
        element = fixture('basic');
        element.prefs = {};
        renderStub = sandbox.stub(element.$.diffBuilder, 'render')
            .returns(new Promise(() => {}));
      });

      test('lineOfInterest is a key location', () => {
        element.lineOfInterest = {number: 789, leftSide: true};
        element._renderDiffTable();
        assert.isTrue(renderStub.called);
        assert.deepEqual(renderStub.lastCall.args[0], {
          left: {789: true},
          right: {},
        });
      });

      test('line comments are key locations', () => {
        const threadEl = document.createElement('div');
        threadEl.className = 'comment-thread';
        threadEl.setAttribute('comment-side', 'right');
        threadEl.setAttribute('line-num', 3);
        Polymer.dom(element).appendChild(threadEl);
        Polymer.dom.flush();

        element._renderDiffTable();
        assert.isTrue(renderStub.called);
        assert.deepEqual(renderStub.lastCall.args[0], {
          left: {},
          right: {3: true},
        });
      });

      test('file comments are key locations', () => {
        const threadEl = document.createElement('div');
        threadEl.className = 'comment-thread';
        threadEl.setAttribute('comment-side', 'left');
        Polymer.dom(element).appendChild(threadEl);
        Polymer.dom.flush();

        element._renderDiffTable();
        assert.isTrue(renderStub.called);
        assert.deepEqual(renderStub.lastCall.args[0], {
          left: {FILE: true},
          right: {},
        });
      });
    });

    suite('whitespace changes only message', () => {
      const setupDiff = function(ignore_whitespace, diffContent) {
        element = fixture('basic');
        element.prefs = {
          ignore_whitespace,
          auto_hide_diff_table_header: true,
          context: 10,
          cursor_blink_rate: 0,
          font_size: 12,
          intraline_difference: true,
          line_length: 100,
          line_wrapping: false,
          show_line_endings: true,
          show_tabs: true,
          show_whitespace_errors: true,
          syntax_highlighting: true,
          tab_size: 8,
          theme: 'DEFAULT',
        };

        element.diff = {
          intraline_status: 'OK',
          change_type: 'MODIFIED',
          diff_header: [
            'diff --git a/carrot.js b/carrot.js',
            'index 2adc47d..f9c2f2c 100644',
            '--- a/carrot.js',
            '+++ b/carrot.jjs',
            'file differ',
          ],
          content: diffContent,
          binary: true,
        };

        element._renderDiffTable();
        flushAsynchronousOperations();
      };

      test('show the message if ignore_whitespace is criteria matches', () => {
        setupDiff('IGNORE_ALL', [{skip: 100}]);
        assert.isTrue(element.showNoChangeMessage(
            /* loading= */ false,
            element.prefs,
            element._diffLength
        ));
      });

      test('do not show the message if still loading', () => {
        setupDiff('IGNORE_ALL', [{skip: 100}]);
        assert.isFalse(element.showNoChangeMessage(
            /* loading= */ true,
            element.prefs,
            element._diffLength
        ));
      });

      test('do not show the message if contains valid changes', () => {
        const 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',
          ],
        }];
        setupDiff('IGNORE_ALL', content);
        assert.equal(element._diffLength, 3);
        assert.isFalse(element.showNoChangeMessage(
            /* loading= */ false,
            element.prefs,
            element._diffLength
        ));
      });

      test('do not show message if ignore whitespace is disabled', () => {
        const 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',
          ],
        }];
        setupDiff('IGNORE_NONE', content);
        assert.isFalse(element.showNoChangeMessage(
            /* loading= */ false,
            element.prefs,
            element._diffLength
        ));
      });
    });

    test('getDiffLength', () => {
      const diff = document.createElement('mock-diff-response').diffResponse;
      assert.equal(element.getDiffLength(diff), 52);
    });

    test('`render` event has contentRendered field in detail', done => {
      element = fixture('basic');
      element.prefs = {};
      renderStub = sandbox.stub(element.$.diffBuilder, 'render')
          .returns(Promise.resolve());
      element.addEventListener('render', event => {
        assert.isTrue(event.detail.contentRendered);
        done();
      });
      element._renderDiffTable();
    });
  });

  a11ySuite('basic');
</script>