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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="../../../bower_components/webcomponentsjs/webcomponents-lite.min.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/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;

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

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

    test('reload cancels before network resolves', () => {
      element = fixture('basic');
      const cancelStub = sandbox.stub(element, 'cancel');

      // Stub the network calls into requests that never resolve.
      sandbox.stub(element, '_getDiff', () => new Promise(() => {}));

      element.reload();
      assert.isTrue(cancelStub.called);
    });

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

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

    test('line limit with line_wrapping', () => {
      element = fixture('basic');
      element.prefs = {line_wrapping: true, line_length: 80, tab_size: 2};
      flushAsynchronousOperations();
      assert.equal(element.customStyle['--line-limit'], '80ch');
    });

    test('line limit without line_wrapping', () => {
      element = fixture('basic');
      element.prefs = {line_wrapping: false, line_length: 80, tab_size: 2};
      flushAsynchronousOperations();
      assert.isNotOk(element.customStyle['--line-limit']);
    });

    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('loads files weblinks', () => {
        const weblinksStub = sandbox.stub(Gerrit.Nav, '_generateWeblinks')
            .returns({name: 'stubb', url: '#s'});
        sandbox.stub(element.$.restAPI, 'getDiff').returns(Promise.resolve({
          content: [],
        }));
        element.projectName = 'test-project';
        element.path = 'test-path';
        element.commitRange = {baseCommit: 'test-base', commit: 'test-commit'};
        element.patchRange = {};
        return element.reload().then(() => {
          assert.isTrue(weblinksStub.calledTwice);
          assert.isTrue(weblinksStub.firstCall.calledWith({
            commit: 'test-base',
            file: 'test-path',
            options: {
              weblinks: undefined,
            },
            repo: 'test-project',
            type: Gerrit.Nav.WeblinkType.FILE}));
          assert.isTrue(weblinksStub.secondCall.calledWith({
            commit: 'test-commit',
            file: 'test-path',
            options: {
              weblinks: undefined,
            },
            repo: 'test-project',
            type: Gerrit.Nav.WeblinkType.FILE}));
          assert.deepEqual(element.filesWeblinks, {
            meta_a: [{name: 'stubb', url: '#s'}],
            meta_b: [{name: 'stubb', url: '#s'}],
          });
        });
      });

      test('remove comment', () => {
        element.comments = {
          meta: {
            changeNum: '42',
            patchRange: {
              basePatchNum: 'PARENT',
              patchNum: 3,
            },
            path: '/path/to/foo',
            projectConfig: {foo: 'bar'},
          },
          left: [
            {id: 'bc1', side: 'PARENT', __commentSide: 'left'},
            {id: 'bc2', side: 'PARENT', __commentSide: 'left'},
            {id: 'bd1', __draft: true, side: 'PARENT', __commentSide: 'left'},
            {id: 'bd2', __draft: true, side: 'PARENT', __commentSide: 'left'},
          ],
          right: [
            {id: 'c1', __commentSide: 'right'},
            {id: 'c2', __commentSide: 'right'},
            {id: 'd1', __draft: true, __commentSide: 'right'},
            {id: 'd2', __draft: true, __commentSide: 'right'},
          ],
        };

        element._removeComment({});
        // Using JSON.stringify because Safari 9.1 (11601.5.17.1) doesn’t seem
        // to believe that one object deepEquals another even when they do :-/.
        assert.equal(JSON.stringify(element.comments), JSON.stringify({
          meta: {
            changeNum: '42',
            patchRange: {
              basePatchNum: 'PARENT',
              patchNum: 3,
            },
            path: '/path/to/foo',
            projectConfig: {foo: 'bar'},
          },
          left: [
            {id: 'bc1', side: 'PARENT', __commentSide: 'left'},
            {id: 'bc2', side: 'PARENT', __commentSide: 'left'},
            {id: 'bd1', __draft: true, side: 'PARENT', __commentSide: 'left'},
            {id: 'bd2', __draft: true, side: 'PARENT', __commentSide: 'left'},
          ],
          right: [
            {id: 'c1', __commentSide: 'right'},
            {id: 'c2', __commentSide: 'right'},
            {id: 'd1', __draft: true, __commentSide: 'right'},
            {id: 'd2', __draft: true, __commentSide: 'right'},
          ],
        }));

        element._removeComment({id: 'bc2', side: 'PARENT',
          __commentSide: 'left'});
        assert.deepEqual(element.comments, {
          meta: {
            changeNum: '42',
            patchRange: {
              basePatchNum: 'PARENT',
              patchNum: 3,
            },
            path: '/path/to/foo',
            projectConfig: {foo: 'bar'},
          },
          left: [
            {id: 'bc1', side: 'PARENT', __commentSide: 'left'},
            {id: 'bd1', __draft: true, side: 'PARENT', __commentSide: 'left'},
            {id: 'bd2', __draft: true, side: 'PARENT', __commentSide: 'left'},
          ],
          right: [
            {id: 'c1', __commentSide: 'right'},
            {id: 'c2', __commentSide: 'right'},
            {id: 'd1', __draft: true, __commentSide: 'right'},
            {id: 'd2', __draft: true, __commentSide: 'right'},
          ],
        });

        element._removeComment({id: 'd2', __commentSide: 'right'});
        assert.deepEqual(element.comments, {
          meta: {
            changeNum: '42',
            patchRange: {
              basePatchNum: 'PARENT',
              patchNum: 3,
            },
            path: '/path/to/foo',
            projectConfig: {foo: 'bar'},
          },
          left: [
            {id: 'bc1', side: 'PARENT', __commentSide: 'left'},
            {id: 'bd1', __draft: true, side: 'PARENT', __commentSide: 'left'},
            {id: 'bd2', __draft: true, side: 'PARENT', __commentSide: 'left'},
          ],
          right: [
            {id: 'c1', __commentSide: 'right'},
            {id: 'c2', __commentSide: 'right'},
            {id: 'd1', __draft: true, __commentSide: 'right'},
          ],
        });
      });

      test('thread groups', () => {
        const contentEl = document.createElement('div');
        const commentSide = 'left';
        const patchNum = 1;
        const side = 'PARENT';
        let range = {
          startLine: 1,
          startChar: 1,
          endLine: 1,
          endChar: 2,
        };

        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, {}, {tab_size: 2, line_length: 80});

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

        // A thread group gets created.
        assert.isOk(element._getOrCreateThread(contentEl,
            patchNum, commentSide, side));

        // Try to fetch a thread with a different range.
        range = {
          startLine: 1,
          startChar: 1,
          endLine: 1,
          endChar: 3,
        };

        assert.isOk(element._getOrCreateThread(
            contentEl, patchNum, commentSide, side, range));
        // The new thread group can be fetched.
        assert.isOk(element._getThreadGroupForLine(contentEl));

        assert.equal(contentEl.querySelectorAll(
            'gr-diff-comment-thread-group').length, 1);

        const threadGroup = contentEl.querySelector(
            'gr-diff-comment-thread-group');
        const threadLength = Polymer.dom(threadGroup.root).
              querySelectorAll('gr-diff-comment-thread').length;
        assert.equal(threadLength, 2);
      });

      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',
          };
          const mockCommit = {
            commit: '9a1a1d10baece5efbba10bc4ccf808a67a50ac0a',
            parents: [{
              commit: '7338aa9adfe57909f1fdaf88975cdea467d3382f',
              subject: 'Added a carrot',
            }],
            author: {
              name: 'Wyatt Allen',
              email: 'wyatta@google.com',
              date: '2016-05-23 21:44:51.000000000',
              tz: -420,
            },
            committer: {
              name: 'Wyatt Allen',
              email: 'wyatta@google.com',
              date: '2016-05-25 00:25:41.000000000',
              tz: -420,
            },
            subject: 'Updated the carrot',
            message: 'Updated the carrot\n\nChange-Id: Iabcd123\n',
          };
          const mockComments = {baseComments: [], comments: []};

          sandbox.stub(element.$.restAPI, 'getCommitInfo')
              .returns(Promise.resolve(mockCommit));
          sandbox.stub(element.$.restAPI,
              'getB64FileContents',
              (changeId, patchNum, path, opt_parentIndex) => {
                return Promise.resolve(opt_parentIndex === 1 ? mockFile1 :
                    mockFile2);
              });
          sandbox.stub(element.$.restAPI, '_getDiffComments')
              .returns(Promise.resolve(mockComments));
          sandbox.stub(element.$.restAPI, 'getDiffDrafts')
              .returns(Promise.resolve(mockComments));

          element.patchRange = {basePatchNum: 'PARENT', patchNum: 1};
          element.comments = {left: [], right: []};
        });

        test('renders image diffs with same file name', done => {
          const mockDiff = {
            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,
          };
          sandbox.stub(element.$.restAPI, 'getDiff')
              .returns(Promise.resolve(mockDiff));

          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.$.restAPI.getDiffPreferences().then(prefs => {
            element.prefs = prefs;
            element.reload();
          });
        });

        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,
          };
          sandbox.stub(element.$.restAPI, 'getDiff')
              .returns(Promise.resolve(mockDiff));

          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.$.restAPI.getDiffPreferences().then(prefs => {
            element.prefs = prefs;
            element.reload();
          });
        });

        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,
          };
          sandbox.stub(element.$.restAPI, 'getDiff')
              .returns(Promise.resolve(mockDiff));

          element.addEventListener('render', () => {
            // 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.$.restAPI.getDiffPreferences().then(prefs => {
            element.prefs = prefs;
            element.reload();
          });
        });

        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,
          };
          sandbox.stub(element.$.restAPI, 'getDiff')
              .returns(Promise.resolve(mockDiff));

          element.addEventListener('render', () => {
            // 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.$.restAPI.getDiffPreferences().then(prefs => {
            element.prefs = prefs;
            element.reload();
          });
        });

        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';

          sandbox.stub(element.$.restAPI, 'getDiff')
              .returns(Promise.resolve(mockDiff));

          element.addEventListener('render', () => {
            // 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.$.restAPI.getDiffPreferences().then(prefs => {
            element.prefs = prefs;
            element.reload();
          });
        });
      });

      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();
      });

      test('_getDiff handles null diff responses', done => {
        stub('gr-rest-api-interface', {
          getDiff() { return Promise.resolve(null); },
        });
        element.changeNum = 123;
        element.patchRange = {basePatchNum: 1, patchNum: 2};
        element.path = 'file.txt';
        element._getDiff().then(done);
      });

      test('reload resolves on error', () => {
        const onErrStub = sandbox.stub(element, '_handleGetDiffError');
        const error = {ok: false, status: 500};
        sandbox.stub(element.$.restAPI, 'getDiff',
            (changeNum, basePatchNum, patchNum, path, onErr) => {
              onErr(error);
            });
        return element.reload().then(() => {
          assert.isTrue(onErrStub.calledOnce);
        });
      });

      suite('_handleGetDiffError', () => {
        let serverErrorStub;
        let pageErrorStub;

        setup(() => {
          serverErrorStub = sinon.stub();
          element.addEventListener('server-error', serverErrorStub);
          pageErrorStub = sinon.stub();
          element.addEventListener('page-error', pageErrorStub);
        });

        test('page error on HTTP-409', () => {
          element._handleGetDiffError({status: 409});
          assert.isTrue(serverErrorStub.calledOnce);
          assert.isFalse(pageErrorStub.called);
          assert.isNotOk(element._errorMessage);
        });

        test('server error on non-HTTP-409', () => {
          element._handleGetDiffError({status: 500});
          assert.isFalse(serverErrorStub.called);
          assert.isTrue(pageErrorStub.calledOnce);
          assert.isNotOk(element._errorMessage);
        });

        test('error message if showLoadFailure', () => {
          element.showLoadFailure = true;
          element._handleGetDiffError({status: 500, statusText: 'Failure!'});
          assert.isFalse(serverErrorStub.called);
          assert.isFalse(pageErrorStub.called);
          assert.equal(element._errorMessage,
              'Encountered error when loading the diff: 500 Failure!');
        });
      });

      suite('getCursorStops', () => {
        const setupDiff = function() {
          const mock = document.createElement('mock-diff-response');
          element._diff = mock.diffResponse;
          element.comments = {
            left: [],
            right: [],
          };
          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(() => {
        const getLoggedInPromise = Promise.resolve(true);
        stub('gr-rest-api-interface', {
          getLoggedIn() { return getLoggedInPromise; },
          getPreferences() {
            return Promise.resolve({time_format: 'HHMM_12'});
          },
          getAccountCapabilities() { return Promise.resolve(); },
        });
        element = fixture('basic');
        element.patchRange = {};

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

      test('addDraftAtLine', () => {
        sandbox.stub(element, '_selectLine');
        sandbox.stub(element, '_createComment');
        const loggedInErrorSpy = sandbox.spy();
        element.addEventListener('show-auth-required', loggedInErrorSpy);
        assert.isFalse(loggedInErrorSpy.called);
        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 loggedInErrorSpy = sandbox.spy();
        const alertSpy = sandbox.spy();
        element.addEventListener('show-auth-required', loggedInErrorSpy);
        element.addEventListener('show-alert', alertSpy);
        element.addDraftAtLine(fakeLineEl);
        assert.isFalse(loggedInErrorSpy.called);
        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 loggedInErrorSpy = sandbox.spy();
        const alertSpy = sandbox.spy();
        element.addEventListener('show-auth-required', loggedInErrorSpy);
        element.addEventListener('show-alert', alertSpy);
        element.addDraftAtLine(fakeLineEl);
        assert.isFalse(loggedInErrorSpy.called);
        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.comments = {
            meta: {
              changeNum: '42',
              patchRange: {
                basePatchNum: 'PARENT',
                patchNum: 3,
              },
              path: '/path/to/foo',
              projectConfig: {foo: 'bar'},
            },
            left: [
              {id: 'bc1', side: 'PARENT', __commentSide: 'left'},
              {id: 'bc2', side: 'PARENT', __commentSide: 'left'},
              {id: 'bd1', __draft: true, side: 'PARENT', __commentSide: 'left'},
              {id: 'bd2', __draft: true, side: 'PARENT', __commentSide: 'left'},
            ],
            right: [
              {id: 'c1', __commentSide: 'right'},
              {id: 'c2', __commentSide: 'right'},
              {id: 'd1', __draft: true, __commentSide: 'right'},
              {id: 'd2', __draft: true, __commentSide: 'right'},
            ],
          };
        });

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

      suite('handle comment-update', () => {
        setup(() => {
          element.comments = {
            meta: {
              changeNum: '42',
              patchRange: {
                basePatchNum: 'PARENT',
                patchNum: 3,
              },
              path: '/path/to/foo',
              projectConfig: {foo: 'bar'},
            },
            left: [
              {id: 'bc1', side: 'PARENT', __commentSide: 'left'},
              {id: 'bc2', side: 'PARENT', __commentSide: 'left'},
              {id: 'bd1', __draft: true, side: 'PARENT', __commentSide: 'left'},
              {id: 'bd2', __draft: true, side: 'PARENT', __commentSide: 'left'},
            ],
            right: [
              {id: 'c1', __commentSide: 'right'},
              {id: 'c2', __commentSide: 'right'},
              {id: 'd1', __draft: true, __commentSide: 'right'},
              {id: 'd2', __draft: true, __commentSide: 'right'},
            ],
          };
        });

        test('creating a draft', () => {
          const comment = {__draft: true, __draftID: 'tempID', side: 'PARENT',
            __commentSide: 'left'};
          element.fire('comment-update', {comment});
          assert.include(element.comments.left, comment);
        });

        test('discarding a draft', () => {
          const draftID = 'tempID';
          const id = 'savedID';
          const comment = {
            __draft: true,
            __draftID: draftID,
            side: 'PARENT',
            __commentSide: 'left',
          };
          const diffCommentsModifiedStub = sandbox.stub();
          element.addEventListener('diff-comments-modified',
              diffCommentsModifiedStub);
          element.comments.left.push(comment);
          comment.id = id;
          element.fire('comment-discard', {comment});
          const drafts = element.comments.left.filter(item => {
            return item.__draftID === draftID;
          });
          assert.equal(drafts.length, 0);
          assert.isTrue(diffCommentsModifiedStub.called);
        });

        test('saving a draft', () => {
          const draftID = 'tempID';
          const id = 'savedID';
          const comment = {
            __draft: true,
            __draftID: draftID,
            side: 'PARENT',
            __commentSide: 'left',
          };
          const diffCommentsModifiedStub = sandbox.stub();
          element.addEventListener('diff-comments-modified',
              diffCommentsModifiedStub);
          element.comments.left.push(comment);
          comment.id = id;
          element.fire('comment-save', {comment});
          const drafts = element.comments.left.filter(item => {
            return item.__draftID === draftID;
          });
          assert.equal(drafts.length, 1);
          assert.equal(drafts[0].id, id);
          assert.isTrue(diffCommentsModifiedStub.called);
        });
      });
    });

    suite('diff header', () => {
      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}],
        };
      });

      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',
            () => Promise.resolve());
        const mock = document.createElement('mock-diff-response');
        element._diff = mock.diffResponse;
        element.comments = {left: [], right: []};
        element.noRenderOnPrefsChange = true;
      });

      test('lage render w/ context = 10', () => {
        element.prefs = {context: 10};
        sandbox.stub(element, '_diffLength', () => 10000);
        return element._renderDiffTable().then(() => {
          assert.isTrue(renderStub.called);
          assert.isFalse(element._showWarning);
        });
      });

      test('lage render w/ whole file and bypass', () => {
        element.prefs = {context: -1};
        element._safetyBypass = 10;
        sandbox.stub(element, '_diffLength', () => 10000);
        return element._renderDiffTable().then(() => {
          assert.isTrue(renderStub.called);
          assert.isFalse(element._showWarning);
        });
      });

      test('lage render w/ whole file and no bypass', () => {
        element.prefs = {context: -1};
        sandbox.stub(element, '_diffLength', () => 10000);
        return element._renderDiffTable().then(() => {
          assert.isFalse(renderStub.called);
          assert.isTrue(element._showWarning);
        });
      });
    });

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

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

      test('loadBlame', () => {
        const mockBlame = [{id: 'commit id', ranges: [{start: 1, end: 2}]}];
        const showAlertStub = sinon.stub();
        element.addEventListener('show-alert', showAlertStub);
        const getBlameStub = sandbox.stub(element.$.restAPI, 'getBlame')
            .returns(Promise.resolve(mockBlame));
        element.changeNum = 42;
        element.patchRange = {patchNum: 5, basePatchNum: 4};
        element.path = 'foo/bar.baz';
        return element.loadBlame().then(() => {
          assert.isTrue(getBlameStub.calledWithExactly(
              42, 5, 'foo/bar.baz', true));
          assert.isFalse(showAlertStub.called);
          assert.equal(element._blame, mockBlame);
          assert.isTrue(element.classList.contains('showBlame'));
        });
      });

      test('loadBlame empty', () => {
        const mockBlame = [];
        const showAlertStub = sinon.stub();
        element.addEventListener('show-alert', showAlertStub);
        sandbox.stub(element.$.restAPI, 'getBlame')
            .returns(Promise.resolve(mockBlame));
        element.changeNum = 42;
        element.patchRange = {patchNum: 5, basePatchNum: 4};
        element.path = 'foo/bar.baz';
        return element.loadBlame()
            .then(() => {
              assert.isTrue(false, 'Promise should not resolve');
            })
            .catch(() => {
              assert.isTrue(showAlertStub.calledOnce);
              assert.isNull(element._blame);
              assert.isFalse(element.classList.contains('showBlame'));
            });
      });
    });

    suite('_reportDiff', () => {
      let reportStub;

      setup(() => {
        element = fixture('basic');
        element.patchRange = {basePatchNum: 1};
        reportStub = sandbox.stub(element.$.reporting, 'reportInteraction');
      });

      test('null and content-less', () => {
        element._reportDiff(null);
        assert.isFalse(reportStub.called);

        element._reportDiff({});
        assert.isFalse(reportStub.called);
      });

      test('diff w/ no delta', () => {
        const diff = {
          content: [
            {ab: ['foo', 'bar']},
            {ab: ['baz', 'foo']},
          ],
        };
        element._reportDiff(diff);
        assert.isTrue(reportStub.calledOnce);
        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-zero');
        assert.isUndefined(reportStub.lastCall.args[1]);
      });

      test('diff w/ no rebase delta', () => {
        const diff = {
          content: [
            {ab: ['foo', 'bar']},
            {a: ['baz', 'foo']},
            {ab: ['foo', 'bar']},
            {a: ['baz', 'foo'], b: ['bar', 'baz']},
            {ab: ['foo', 'bar']},
            {b: ['baz', 'foo']},
            {ab: ['foo', 'bar']},
          ],
        };
        element._reportDiff(diff);
        assert.isTrue(reportStub.calledOnce);
        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-zero');
        assert.isUndefined(reportStub.lastCall.args[1]);
      });

      test('diff w/ some rebase delta', () => {
        const diff = {
          content: [
            {ab: ['foo', 'bar']},
            {a: ['baz', 'foo'], due_to_rebase: true},
            {ab: ['foo', 'bar']},
            {a: ['baz', 'foo'], b: ['bar', 'baz']},
            {ab: ['foo', 'bar']},
            {b: ['baz', 'foo'], due_to_rebase: true},
            {ab: ['foo', 'bar']},
            {a: ['baz', 'foo']},
          ],
        };
        element._reportDiff(diff);
        assert.isTrue(reportStub.calledOnce);
        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-nonzero');
        assert.strictEqual(reportStub.lastCall.args[1], 50);
      });

      test('diff w/ all rebase delta', () => {
        const diff = {content: [{
          a: ['foo', 'bar'],
          b: ['baz', 'foo'],
          due_to_rebase: true,
        }]};
        element._reportDiff(diff);
        assert.isTrue(reportStub.calledOnce);
        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-nonzero');
        assert.strictEqual(reportStub.lastCall.args[1], 100);
      });

      test('diff against parent event', () => {
        element.patchRange.basePatchNum = 'PARENT';
        const diff = {content: [{
          a: ['foo', 'bar'],
          b: ['baz', 'foo'],
        }]};
        element._reportDiff(diff);
        assert.isTrue(reportStub.calledOnce);
        assert.equal(reportStub.lastCall.args[0], 'diff-against-parent');
        assert.isUndefined(reportStub.lastCall.args[1]);
      });
    });

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

        test('deletion', () => {
          const diff = {content: [
            {a: ['foo', 'bar', 'baz']},
          ]};
          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);
      });
    });
  });

  a11ySuite('basic');
</script>