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<meta name="viewport" content="width=device-width, minimum-scale=1.0, initial-scale=1.0, user-scalable=yes">
<title>gr-change-view</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="../../../bower_components/page/page.js"></script>

<link rel="import" href="../../edit/gr-edit-constants.html">
<link rel="import" href="gr-change-view.html">

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

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

<test-fixture id="blank">
  <template>
    <div></div>
  </template>
</test-fixture>

<script>
  suite('gr-change-view tests', () => {
    const kb = window.Gerrit.KeyboardShortcutBinder;
    kb.bindShortcut(kb.Shortcut.SEND_REPLY, 'ctrl+enter');
    kb.bindShortcut(kb.Shortcut.REFRESH_CHANGE, 'shift+r');
    kb.bindShortcut(kb.Shortcut.OPEN_REPLY_DIALOG, 'a');
    kb.bindShortcut(kb.Shortcut.OPEN_DOWNLOAD_DIALOG, 'd');
    kb.bindShortcut(kb.Shortcut.TOGGLE_DIFF_MODE, 'm');
    kb.bindShortcut(kb.Shortcut.TOGGLE_CHANGE_STAR, 's');
    kb.bindShortcut(kb.Shortcut.UP_TO_DASHBOARD, 'u');
    kb.bindShortcut(kb.Shortcut.EXPAND_ALL_MESSAGES, 'x');
    kb.bindShortcut(kb.Shortcut.COLLAPSE_ALL_MESSAGES, 'z');
    kb.bindShortcut(kb.Shortcut.OPEN_DIFF_PREFS, ',');
    kb.bindShortcut(kb.Shortcut.EDIT_TOPIC, 't');

    let element;
    let sandbox;
    let navigateToChangeStub;
    const TEST_SCROLL_TOP_PX = 100;

    setup(() => {
      sandbox = sinon.sandbox.create();
      stub('gr-endpoint-decorator', {
        _import: sandbox.stub().returns(Promise.resolve()),
      });
      // Since _endpoints are global, must reset state.
      Gerrit._endpoints = new GrPluginEndpoints();
      navigateToChangeStub = sandbox.stub(Gerrit.Nav, 'navigateToChange');
      stub('gr-rest-api-interface', {
        getConfig() { return Promise.resolve({test: 'config'}); },
        getAccount() { return Promise.resolve(null); },
        getDiffComments() { return Promise.resolve({}); },
        getDiffRobotComments() { return Promise.resolve({}); },
        getDiffDrafts() { return Promise.resolve({}); },
        _fetchSharedCacheURL() { return Promise.resolve({}); },
      });
      element = fixture('basic');
      sandbox.stub(element.$.actions, 'reload').returns(Promise.resolve());
      Gerrit._setPluginsCount(0);
    });

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

    getCustomCssValue = cssParam => {
      // TODO: Update to be compatible with 2.x when we upgrade from
      // 1.x to 2.x.
      return element.getComputedStyleValue(cssParam);
    };

    test('_handleMessageAnchorTap', () => {
      element._changeNum = '1';
      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: 1,
      };
      const getUrlStub = sandbox.stub(Gerrit.Nav, 'getUrlForChange');
      const replaceStateStub = sandbox.stub(history, 'replaceState');
      element._handleMessageAnchorTap({detail: {id: 'a12345'}});

      assert.equal(getUrlStub.lastCall.args[4], '#message-a12345');
      assert.isTrue(replaceStateStub.called);
    });

    suite('keyboard shortcuts', () => {
      test('t to add topic', () => {
        const editStub = sandbox.stub(element.$.metadata, 'editTopic');
        MockInteractions.pressAndReleaseKeyOn(element, 83, null, 't');
        assert(editStub.called);
      });

      test('S should toggle the CL star', () => {
        const starStub = sandbox.stub(element.$.changeStar, 'toggleStar');
        MockInteractions.pressAndReleaseKeyOn(element, 83, null, 's');
        assert(starStub.called);
      });

      test('U should navigate to root if no backPage set', () => {
        const relativeNavStub = sandbox.stub(Gerrit.Nav,
            'navigateToRelativeUrl');
        MockInteractions.pressAndReleaseKeyOn(element, 85, null, 'u');
        assert.isTrue(relativeNavStub.called);
        assert.isTrue(relativeNavStub.lastCall.calledWithExactly(
            Gerrit.Nav.getUrlForRoot()));
      });

      test('U should navigate to backPage if set', () => {
        const relativeNavStub = sandbox.stub(Gerrit.Nav,
            'navigateToRelativeUrl');
        element.backPage = '/dashboard/self';
        MockInteractions.pressAndReleaseKeyOn(element, 85, null, 'u');
        assert.isTrue(relativeNavStub.called);
        assert.isTrue(relativeNavStub.lastCall.calledWithExactly(
            '/dashboard/self'));
      });

      test('A fires an error event when not logged in', done => {
        sandbox.stub(element, '_getLoggedIn').returns(Promise.resolve(false));
        const loggedInErrorSpy = sandbox.spy();
        element.addEventListener('show-auth-required', loggedInErrorSpy);
        MockInteractions.pressAndReleaseKeyOn(element, 65, null, 'a');
        flush(() => {
          assert.isFalse(element.$.replyOverlay.opened);
          assert.isTrue(loggedInErrorSpy.called);
          done();
        });
      });

      test('shift A does not open reply overlay', done => {
        sandbox.stub(element, '_getLoggedIn').returns(Promise.resolve(true));
        MockInteractions.pressAndReleaseKeyOn(element, 65, 'shift', 'a');
        flush(() => {
          assert.isFalse(element.$.replyOverlay.opened);
          done();
        });
      });

      test('A toggles overlay when logged in', done => {
        sandbox.stub(element, '_getLoggedIn').returns(Promise.resolve(true));
        sandbox.stub(element.$.replyDialog, 'fetchChangeUpdates')
            .returns(Promise.resolve({isLatest: true}));
        element._change = {labels: {}};
        const openSpy = sandbox.spy(element, '_openReplyDialog');

        MockInteractions.pressAndReleaseKeyOn(element, 65, null, 'a');
        flush(() => {
          assert.isTrue(element.$.replyOverlay.opened);
          element.$.replyOverlay.close();
          assert.isFalse(element.$.replyOverlay.opened);
          assert(openSpy.lastCall.calledWithExactly(
              element.$.replyDialog.FocusTarget.ANY),
          '_openReplyDialog should have been passed ANY');
          assert.equal(openSpy.callCount, 1);
          done();
        });
      });

      test('fullscreen-overlay-opened hides content', () => {
        element._loggedIn = true;
        element._loading = false;
        element._change = {
          owner: {_account_id: 1},
          labels: {},
          actions: {
            abandon: {
              enabled: true,
              label: 'Abandon',
              method: 'POST',
              title: 'Abandon',
            },
          },
        };
        sandbox.spy(element, '_handleHideBackgroundContent');
        element.$.replyDialog.fire('fullscreen-overlay-opened');
        assert.isTrue(element._handleHideBackgroundContent.called);
        assert.isTrue(element.$.mainContent.classList.contains('overlayOpen'));
        assert.equal(getComputedStyle(element.$.actions).display, 'flex');
      });

      test('fullscreen-overlay-closed shows content', () => {
        element._loggedIn = true;
        element._loading = false;
        element._change = {
          owner: {_account_id: 1},
          labels: {},
          actions: {
            abandon: {
              enabled: true,
              label: 'Abandon',
              method: 'POST',
              title: 'Abandon',
            },
          },
        };
        sandbox.spy(element, '_handleShowBackgroundContent');
        element.$.replyDialog.fire('fullscreen-overlay-closed');
        assert.isTrue(element._handleShowBackgroundContent.called);
        assert.isFalse(element.$.mainContent.classList.contains('overlayOpen'));
      });

      test('expand all messages when expand-diffs fired', () => {
        const handleExpand =
            sandbox.stub(element.$.fileList, 'expandAllDiffs');
        element.$.fileListHeader.fire('expand-diffs');
        assert.isTrue(handleExpand.called);
      });

      test('collapse all messages when collapse-diffs fired', () => {
        const handleCollapse =
        sandbox.stub(element.$.fileList, 'collapseAllDiffs');
        element.$.fileListHeader.fire('collapse-diffs');
        assert.isTrue(handleCollapse.called);
      });

      test('X should expand all messages', done => {
        flush(() => {
          const handleExpand = sandbox.stub(element.messagesList,
              'handleExpandCollapse');
          MockInteractions.pressAndReleaseKeyOn(element, 88, null, 'x');
          assert(handleExpand.calledWith(true));
          done();
        });
      });

      test('Z should collapse all messages', done => {
        flush(() => {
          const handleExpand = sandbox.stub(element.messagesList,
              'handleExpandCollapse');
          MockInteractions.pressAndReleaseKeyOn(element, 90, null, 'z');
          assert(handleExpand.calledWith(false));
          done();
        });
      });

      test('shift + R should fetch and navigate to the latest patch set',
          done => {
            element._changeNum = '42';
            element._patchRange = {
              basePatchNum: 'PARENT',
              patchNum: 1,
            };
            element._change = {
              change_id: 'Iad9dc96274af6946f3632be53b106ef80f7ba6ca',
              _number: 42,
              revisions: {
                rev1: {_number: 1, commit: {parents: []}},
              },
              current_revision: 'rev1',
              status: 'NEW',
              labels: {},
              actions: {},
            };

            navigateToChangeStub.restore();
            navigateToChangeStub = sandbox.stub(Gerrit.Nav, 'navigateToChange',
                (change, patchNum, basePatchNum) => {
                  assert.equal(change, element._change);
                  assert.isUndefined(patchNum);
                  assert.isUndefined(basePatchNum);
                  done();
                });

            MockInteractions.pressAndReleaseKeyOn(element, 82, 'shift', 'r');
          });

      test('d should open download overlay', () => {
        const stub = sandbox.stub(element.$.downloadOverlay, 'open');
        MockInteractions.pressAndReleaseKeyOn(element, 68, null, 'd');
        assert.isTrue(stub.called);
      });

      test(', should open diff preferences', () => {
        const stub = sandbox.stub(
            element.$.fileList.$.diffPreferencesDialog, 'open');
        element._loggedIn = false;
        element.disableDiffPrefs = true;
        MockInteractions.pressAndReleaseKeyOn(element, 188, null, ',');
        assert.isFalse(stub.called);

        element._loggedIn = true;
        MockInteractions.pressAndReleaseKeyOn(element, 188, null, ',');
        assert.isFalse(stub.called);

        element.disableDiffPrefs = false;
        MockInteractions.pressAndReleaseKeyOn(element, 188, null, ',');
        assert.isTrue(stub.called);
      });

      test('m should toggle diff mode', () => {
        sandbox.stub(element, 'shouldSuppressKeyboardShortcut').returns(false);
        const setModeStub = sandbox.stub(element.$.fileListHeader,
            'setDiffViewMode');
        const e = {preventDefault: () => {}};
        flushAsynchronousOperations();

        element.viewState.diffMode = 'SIDE_BY_SIDE';
        element._handleToggleDiffMode(e);
        assert.isTrue(setModeStub.calledWith('UNIFIED_DIFF'));

        element.viewState.diffMode = 'UNIFIED_DIFF';
        element._handleToggleDiffMode(e);
        assert.isTrue(setModeStub.calledWith('SIDE_BY_SIDE'));
      });
    });

    suite('reloading drafts', () => {
      let reloadStub;
      const drafts = {
        'testfile.txt': [
          {
            patch_set: 5,
            id: 'dd2982f5_c01c9e6a',
            line: 1,
            updated: '2017-11-08 18:47:45.000000000',
            message: 'test',
            unresolved: true,
          },
        ],
      };
      setup(() => {
        reloadStub = sandbox.stub(element.$.commentAPI, 'reloadDrafts')
            .returns(Promise.resolve({drafts}));
      });

      test('drafts are reloaded when reload-drafts fired', done => {
        element.$.fileList.fire('reload-drafts', {
          resolve: () => {
            assert.isTrue(reloadStub.called);
            assert.deepEqual(element._diffDrafts, drafts);
            done();
          },
        });
      });

      test('drafts are reloaded when comment-refresh fired', () => {
        element.fire('comment-refresh');
        assert.isTrue(reloadStub.called);
      });
    });

    test('diff comments modified', () => {
      sandbox.spy(element, '_handleReloadCommentThreads');
      return element._reloadComments().then(() => {
        element.fire('diff-comments-modified');
        assert.isTrue(element._handleReloadCommentThreads.called);
      });
    });

    test('thread list modified', () => {
      sandbox.spy(element, '_handleReloadDiffComments');
      element._showMessagesView = false;
      flushAsynchronousOperations();

      return element._reloadComments().then(() => {
        element.threadList.fire('thread-list-modified');
        assert.isTrue(element._handleReloadDiffComments.called);

        let draftStub = sinon.stub(element._changeComments, 'computeDraftCount')
            .returns(1);
        assert.equal(element._computeTotalCommentCounts(5,
            element._changeComments), '5 unresolved, 1 draft');
        assert.equal(element._computeTotalCommentCounts(0,
            element._changeComments), '1 draft');
        draftStub.restore();
        draftStub = sinon.stub(element._changeComments, 'computeDraftCount')
            .returns(0);
        assert.equal(element._computeTotalCommentCounts(0,
            element._changeComments), '');
        assert.equal(element._computeTotalCommentCounts(1,
            element._changeComments), '1 unresolved');
        draftStub.restore();
        draftStub = sinon.stub(element._changeComments, 'computeDraftCount')
            .returns(2);
        assert.equal(element._computeTotalCommentCounts(1,
            element._changeComments), '1 unresolved, 2 drafts');
        draftStub.restore();
      });
    });

    test('thread list and change log tabs', done => {
      element._changeNum = '1';
      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: 1,
      };
      element._change = {
        change_id: 'Iad9dc96274af6946f3632be53b106ef80f7ba6ca',
        revisions: {
          rev2: {_number: 2, commit: {parents: []}},
          rev1: {_number: 1, commit: {parents: []}},
          rev13: {_number: 13, commit: {parents: []}},
          rev3: {_number: 3, commit: {parents: []}},
        },
        current_revision: 'rev3',
        status: 'NEW',
        labels: {
          test: {
            all: [],
            default_value: 0,
            values: [],
            approved: {},
          },
        },
      };
      sandbox.stub(element.$.relatedChanges, 'reload');
      sandbox.stub(element, '_reload').returns(Promise.resolve());
      sandbox.spy(element, '_paramsChanged');
      element.params = {view: 'change', changeNum: '1'};

      // When the change is hard reloaded, paramsChanged will not set the tab.
      // It will be set in postLoadTasks, which requires the flush() to detect.
      assert.isTrue(element._paramsChanged.called);
      assert.isUndefined(element.$.commentTabs.selected);

      // Wait for tab to get selected
      flush(() => {
        assert.equal(element.$.commentTabs.selected, 0);
        assert.isTrue(element._showMessagesView);
        // Switch to comment thread tab
        MockInteractions.tap(element.$$('paper-tab.commentThreads'));
        assert.equal(element.$.commentTabs.selected, 1);
        assert.isFalse(element._showMessagesView);

        // When the change is partially reloaded (ex: Shift+R), the content
        // is swapped out before the tab, so messages list will display even
        // though the tab for comment threads is still temporarily selected.
        element._paramsChanged(element.params);
        assert.equal(element.$.commentTabs.selected, 1);
        assert.isTrue(element._showMessagesView);
        done();
      });
    });

    test('reply button is not visible when logged out', () => {
      assert.equal(getComputedStyle(element.$.replyBtn).display, 'none');
      element._loggedIn = true;
      assert.notEqual(getComputedStyle(element.$.replyBtn).display, 'none');
    });

    test('download tap calls _handleOpenDownloadDialog', () => {
      sandbox.stub(element, '_handleOpenDownloadDialog');
      element.$.actions.fire('download-tap');
      assert.isTrue(element._handleOpenDownloadDialog.called);
    });

    test('fetches the server config on attached', done => {
      flush(() => {
        assert.equal(element._serverConfig.test, 'config');
        done();
      });
    });

    test('_changeStatuses', () => {
      sandbox.stub(element, 'changeStatuses').returns(
          ['Merged', 'WIP']);
      element._loading = false;
      element._change = {
        change_id: 'Iad9dc96274af6946f3632be53b106ef80f7ba6ca',
        revisions: {
          rev2: {_number: 2},
          rev1: {_number: 1},
          rev13: {_number: 13},
          rev3: {_number: 3},
        },
        current_revision: 'rev3',
        labels: {
          test: {
            all: [],
            default_value: 0,
            values: [],
            approved: {},
          },
        },
      };
      element._mergeable = true;
      expectedStatuses = ['Merged', 'WIP'];
      assert.deepEqual(element._changeStatuses, expectedStatuses);
      assert.equal(element._changeStatus, expectedStatuses.join(', '));
      flushAsynchronousOperations();
      const statusChips = Polymer.dom(element.root)
          .querySelectorAll('gr-change-status');
      assert.equal(statusChips.length, 2);
    });

    test('diff preferences open when open-diff-prefs is fired', () => {
      const overlayOpenStub = sandbox.stub(element.$.fileList,
          'openDiffPrefs');
      element.$.fileListHeader.fire('open-diff-prefs');
      assert.isTrue(overlayOpenStub.called);
    });

    test('_prepareCommitMsgForLinkify', () => {
      let commitMessage = 'R=test@google.com';
      let result = element._prepareCommitMsgForLinkify(commitMessage);
      assert.equal(result, 'R=\u200Btest@google.com');

      commitMessage = 'R=test@google.com\nR=test@google.com';
      result = element._prepareCommitMsgForLinkify(commitMessage);
      assert.equal(result, 'R=\u200Btest@google.com\nR=\u200Btest@google.com');

      commitMessage = 'CC=test@google.com';
      result = element._prepareCommitMsgForLinkify(commitMessage);
      assert.equal(result, 'CC=\u200Btest@google.com');
    }),

    test('_updateRebaseAction', () => {
      const currentRevisionActions = {
        cherrypick: {
          enabled: true,
          label: 'Cherry Pick',
          method: 'POST',
          title: 'cherrypick',
        },
        rebase: {
          enabled: true,
          label: 'Rebase',
          method: 'POST',
          title: 'Rebase onto tip of branch or parent change',
        },
      };
      element._parentIsCurrent = undefined;

      // Rebase enabled should always end up true.
      // When rebase is enabled initially, rebaseOnCurrent should be set to
      // true.
      assert.equal(element._updateRebaseAction(currentRevisionActions),
          currentRevisionActions);

      assert.isTrue(currentRevisionActions.rebase.enabled);
      assert.isTrue(currentRevisionActions.rebase.rebaseOnCurrent);
      assert.isFalse(element._parentIsCurrent);

      delete currentRevisionActions.rebase.enabled;

      // When rebase is not enabled initially, rebaseOnCurrent should be set to
      // false.
      assert.equal(element._updateRebaseAction(currentRevisionActions),
          currentRevisionActions);

      assert.isTrue(currentRevisionActions.rebase.enabled);
      assert.isFalse(currentRevisionActions.rebase.rebaseOnCurrent);
      assert.isTrue(element._parentIsCurrent);
    });

    test('_isSubmitEnabled', () => {
      assert.isFalse(element._isSubmitEnabled({}));
      assert.isFalse(element._isSubmitEnabled({actions: {}}));
      assert.isFalse(element._isSubmitEnabled({actions: {submit: {}}}));
      assert.isTrue(element._isSubmitEnabled(
          {actions: {submit: {enabled: true}}}));
    });

    test('_updateRebaseAction sets _parentIsCurrent on no rebase', () => {
      const currentRevisionActions = {
        cherrypick: {
          enabled: true,
          label: 'Cherry Pick',
          method: 'POST',
          title: 'cherrypick',
        },
      };
      element._parentIsCurrent = undefined;
      element._updateRebaseAction(currentRevisionActions);
      assert.isTrue(element._parentIsCurrent);
    });

    test('_reload is called when an approved label is removed', () => {
      const vote = {_account_id: 1, name: 'bojack', value: 1};
      element._changeNum = '42';
      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: 1,
      };
      element._change = {
        change_id: 'Iad9dc96274af6946f3632be53b106ef80f7ba6ca',
        owner: {email: 'abc@def'},
        revisions: {
          rev2: {_number: 2, commit: {parents: []}},
          rev1: {_number: 1, commit: {parents: []}},
          rev13: {_number: 13, commit: {parents: []}},
          rev3: {_number: 3, commit: {parents: []}},
        },
        current_revision: 'rev3',
        status: 'NEW',
        labels: {
          test: {
            all: [vote],
            default_value: 0,
            values: [],
            approved: {},
          },
        },
      };
      flushAsynchronousOperations();
      const reloadStub = sandbox.stub(element, '_reload');
      element.splice('_change.labels.test.all', 0, 1);
      assert.isFalse(reloadStub.called);
      element._change.labels.test.all.push(vote);
      element._change.labels.test.all.push(vote);
      element._change.labels.test.approved = vote;
      flushAsynchronousOperations();
      element.splice('_change.labels.test.all', 0, 2);
      assert.isTrue(reloadStub.called);
      assert.isTrue(reloadStub.calledOnce);
    });

    test('reply button has updated count when there are drafts', () => {
      const getLabel = element._computeReplyButtonLabel;

      assert.equal(getLabel(null, false), 'Reply');
      assert.equal(getLabel(null, true), 'Start review');

      const changeRecord = {base: null};
      assert.equal(getLabel(changeRecord, false), 'Reply');

      changeRecord.base = {};
      assert.equal(getLabel(changeRecord, false), 'Reply');

      changeRecord.base = {
        'file1.txt': [{}],
        'file2.txt': [{}, {}],
      };
      assert.equal(getLabel(changeRecord, false), 'Reply (3)');
    });

    test('start review button when owner of WIP change', () => {
      assert.equal(
          element._computeReplyButtonLabel(null, true),
          'Start review');
    });

    test('comment events properly update diff drafts', () => {
      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: 2,
      };
      const draft = {
        __draft: true,
        id: 'id1',
        path: '/foo/bar.txt',
        text: 'hello',
      };
      element._handleCommentSave({detail: {comment: draft}});
      draft.patch_set = 2;
      assert.deepEqual(element._diffDrafts, {'/foo/bar.txt': [draft]});
      draft.patch_set = null;
      draft.text = 'hello, there';
      element._handleCommentSave({detail: {comment: draft}});
      draft.patch_set = 2;
      assert.deepEqual(element._diffDrafts, {'/foo/bar.txt': [draft]});
      const draft2 = {
        __draft: true,
        id: 'id2',
        path: '/foo/bar.txt',
        text: 'hola',
      };
      element._handleCommentSave({detail: {comment: draft2}});
      draft2.patch_set = 2;
      assert.deepEqual(element._diffDrafts, {'/foo/bar.txt': [draft, draft2]});
      draft.patch_set = null;
      element._handleCommentDiscard({detail: {comment: draft}});
      draft.patch_set = 2;
      assert.deepEqual(element._diffDrafts, {'/foo/bar.txt': [draft2]});
      element._handleCommentDiscard({detail: {comment: draft2}});
      assert.deepEqual(element._diffDrafts, {});
    });

    test('change num change', () => {
      element._changeNum = null;
      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: 2,
      };
      element._change = {
        change_id: 'Iad9dc96274af6946f3632be53b106ef80f7ba6ca',
        labels: {},
      };
      element.viewState.changeNum = null;
      element.viewState.diffMode = 'UNIFIED';
      assert.equal(element.viewState.numFilesShown, 200);
      assert.equal(element._numFilesShown, 200);
      element._numFilesShown = 150;
      flushAsynchronousOperations();
      assert.equal(element.viewState.diffMode, 'UNIFIED');
      assert.equal(element.viewState.numFilesShown, 150);

      element._changeNum = '1';
      element.params = {changeNum: '1'};
      element._change.newProp = '1';
      flushAsynchronousOperations();
      assert.equal(element.viewState.diffMode, 'UNIFIED');
      assert.equal(element.viewState.changeNum, '1');

      element._changeNum = '2';
      element.params = {changeNum: '2'};
      element._change.newProp = '2';
      flushAsynchronousOperations();
      assert.equal(element.viewState.diffMode, 'UNIFIED');
      assert.equal(element.viewState.changeNum, '2');
      assert.equal(element.viewState.numFilesShown, 200);
      assert.equal(element._numFilesShown, 200);
    });

    test('_setDiffViewMode is called with reset when new change is loaded',
        () => {
          sandbox.stub(element, '_setDiffViewMode');
          element.viewState = {changeNum: 1};
          element._changeNum = 2;
          element._resetFileListViewState();
          assert.isTrue(
              element._setDiffViewMode.lastCall.calledWithExactly(true));
        });

    test('diffViewMode is propagated from file list header', () => {
      element.viewState = {diffMode: 'UNIFIED'};
      element.$.fileListHeader.diffViewMode = 'SIDE_BY_SIDE';
      assert.equal(element.viewState.diffMode, 'SIDE_BY_SIDE');
    });

    test('diffMode defaults to side by side without preferences', done => {
      sandbox.stub(element.$.restAPI, 'getPreferences').returns(
          Promise.resolve({}));
      // No user prefs or diff view mode set.

      element._setDiffViewMode().then(() => {
        assert.equal(element.viewState.diffMode, 'SIDE_BY_SIDE');
        done();
      });
    });

    test('diffMode defaults to preference when not already set', done => {
      sandbox.stub(element.$.restAPI, 'getPreferences').returns(
          Promise.resolve({default_diff_view: 'UNIFIED'}));

      element._setDiffViewMode().then(() => {
        assert.equal(element.viewState.diffMode, 'UNIFIED');
        done();
      });
    });

    test('existing diffMode overrides preference', done => {
      element.viewState.diffMode = 'SIDE_BY_SIDE';
      sandbox.stub(element.$.restAPI, 'getPreferences').returns(
          Promise.resolve({default_diff_view: 'UNIFIED'}));
      element._setDiffViewMode().then(() => {
        assert.equal(element.viewState.diffMode, 'SIDE_BY_SIDE');
        done();
      });
    });

    test('don’t reload entire page when patchRange changes', () => {
      const reloadStub = sandbox.stub(element, '_reload',
          () => { return Promise.resolve(); });
      const reloadPatchDependentStub = sandbox.stub(element,
          '_reloadPatchNumDependentResources',
          () => { return Promise.resolve(); });
      const relatedClearSpy = sandbox.spy(element.$.relatedChanges, 'clear');
      const collapseStub = sandbox.stub(element.$.fileList, 'collapseAllDiffs');

      const value = {
        view: Gerrit.Nav.View.CHANGE,
        patchNum: '1',
      };
      element._paramsChanged(value);
      assert.isTrue(reloadStub.calledOnce);
      assert.isTrue(relatedClearSpy.calledOnce);

      element._initialLoadComplete = true;

      value.basePatchNum = '1';
      value.patchNum = '2';
      element._paramsChanged(value);
      assert.isFalse(reloadStub.calledTwice);
      assert.isTrue(reloadPatchDependentStub.calledOnce);
      assert.isTrue(relatedClearSpy.calledOnce);
      assert.isTrue(collapseStub.calledTwice);
    });

    test('reload entire page when patchRange doesnt change', () => {
      const reloadStub = sandbox.stub(element, '_reload',
          () => { return Promise.resolve(); });
      const collapseStub = sandbox.stub(element.$.fileList, 'collapseAllDiffs');
      const value = {
        view: Gerrit.Nav.View.CHANGE,
      };
      element._paramsChanged(value);
      assert.isTrue(reloadStub.calledOnce);
      element._initialLoadComplete = true;
      element._paramsChanged(value);
      assert.isTrue(reloadStub.calledTwice);
      assert.isTrue(collapseStub.calledTwice);
    });

    test('related changes are updated and new patch selected after rebase',
        done => {
          element._changeNum = '42';
          sandbox.stub(element, 'computeLatestPatchNum', () => {
            return 1;
          });
          sandbox.stub(element, '_reload',
              () => { return Promise.resolve(); });
          const e = {detail: {action: 'rebase'}};
          element._handleReloadChange(e).then(() => {
            assert.isTrue(navigateToChangeStub.lastCall.calledWithExactly(
                element._change));
            done();
          });
        });

    test('related changes are not updated after other action', done => {
      sandbox.stub(element, '_reload', () => { return Promise.resolve(); });
      sandbox.stub(element.$.relatedChanges, 'reload');
      const e = {detail: {action: 'abandon'}};
      element._handleReloadChange(e).then(() => {
        assert.isFalse(navigateToChangeStub.called);
        done();
      });
    });

    test('_computeMergedCommitInfo', () => {
      const dummyRevs = {
        1: {commit: {commit: 1}},
        2: {commit: {}},
      };
      assert.deepEqual(element._computeMergedCommitInfo(0, dummyRevs), {});
      assert.deepEqual(element._computeMergedCommitInfo(1, dummyRevs),
          dummyRevs[1].commit);

      // Regression test for issue 5337.
      const commit = element._computeMergedCommitInfo(2, dummyRevs);
      assert.notDeepEqual(commit, dummyRevs[2]);
      assert.deepEqual(commit, {commit: 2});
    });

    test('get latest revision', () => {
      let change = {
        revisions: {
          rev1: {_number: 1},
          rev3: {_number: 3},
        },
        current_revision: 'rev3',
      };
      assert.equal(element._getLatestRevisionSHA(change), 'rev3');
      change = {
        revisions: {
          rev1: {_number: 1},
        },
      };
      assert.equal(element._getLatestRevisionSHA(change), 'rev1');
    });

    test('show commit message edit button', () => {
      const _change = {
        status: element.ChangeStatus.MERGED,
      };
      assert.isTrue(element._computeHideEditCommitMessage(false, false, {}));
      assert.isTrue(element._computeHideEditCommitMessage(true, true, {}));
      assert.isTrue(element._computeHideEditCommitMessage(false, true, {}));
      assert.isFalse(element._computeHideEditCommitMessage(true, false, {}));
      assert.isTrue(element._computeHideEditCommitMessage(true, false,
          _change));
      assert.isTrue(element._computeHideEditCommitMessage(true, false, {},
          true));
      assert.isFalse(element._computeHideEditCommitMessage(true, false, {},
          false));
    });

    test('_handleCommitMessageSave trims trailing whitespace', () => {
      const putStub = sandbox.stub(element.$.restAPI, 'putChangeCommitMessage')
          .returns(Promise.resolve({}));

      const mockEvent = content => { return {detail: {content}}; };

      element._handleCommitMessageSave(mockEvent('test \n  test '));
      assert.equal(putStub.lastCall.args[1], 'test\n  test');

      element._handleCommitMessageSave(mockEvent('  test\ntest'));
      assert.equal(putStub.lastCall.args[1], '  test\ntest');

      element._handleCommitMessageSave(mockEvent('\n\n\n\n\n\n\n\n'));
      assert.equal(putStub.lastCall.args[1], '\n\n\n\n\n\n\n\n');
    });

    test('_computeChangeIdCommitMessageError', () => {
      let commitMessage =
        'Change-Id: I4ce18b2395bca69d7a9aa48bf4554faa56282483';
      let change = {change_id: 'I4ce18b2395bca69d7a9aa48bf4554faa56282483'};
      assert.equal(
          element._computeChangeIdCommitMessageError(commitMessage, change),
          null);

      change = {change_id: 'I4ce18b2395bca69d7a9aa48bf4554faa56282484'};
      assert.equal(
          element._computeChangeIdCommitMessageError(commitMessage, change),
          'mismatch');

      commitMessage = 'This is the greatest change.';
      assert.equal(
          element._computeChangeIdCommitMessageError(commitMessage, change),
          'missing');
    });

    test('multiple change Ids in commit message picks last', () => {
      const commitMessage = [
        'Change-Id: I4ce18b2395bca69d7a9aa48bf4554faa56282484',
        'Change-Id: I4ce18b2395bca69d7a9aa48bf4554faa56282483',
      ].join('\n');
      let change = {change_id: 'I4ce18b2395bca69d7a9aa48bf4554faa56282483'};
      assert.equal(
          element._computeChangeIdCommitMessageError(commitMessage, change),
          null);
      change = {change_id: 'I4ce18b2395bca69d7a9aa48bf4554faa56282484'};
      assert.equal(
          element._computeChangeIdCommitMessageError(commitMessage, change),
          'mismatch');
    });

    test('does not count change Id that starts mid line', () => {
      const commitMessage = [
        'Change-Id: I4ce18b2395bca69d7a9aa48bf4554faa56282484',
        'Change-Id: I4ce18b2395bca69d7a9aa48bf4554faa56282483',
      ].join(' and ');
      let change = {change_id: 'I4ce18b2395bca69d7a9aa48bf4554faa56282484'};
      assert.equal(
          element._computeChangeIdCommitMessageError(commitMessage, change),
          null);
      change = {change_id: 'I4ce18b2395bca69d7a9aa48bf4554faa56282483'};
      assert.equal(
          element._computeChangeIdCommitMessageError(commitMessage, change),
          'mismatch');
    });

    test('_computeTitleAttributeWarning', () => {
      let changeIdCommitMessageError = 'missing';
      assert.equal(
          element._computeTitleAttributeWarning(changeIdCommitMessageError),
          'No Change-Id in commit message');

      changeIdCommitMessageError = 'mismatch';
      assert.equal(
          element._computeTitleAttributeWarning(changeIdCommitMessageError),
          'Change-Id mismatch');
    });

    test('_computeChangeIdClass', () => {
      let changeIdCommitMessageError = 'missing';
      assert.equal(
          element._computeChangeIdClass(changeIdCommitMessageError), '');

      changeIdCommitMessageError = 'mismatch';
      assert.equal(
          element._computeChangeIdClass(changeIdCommitMessageError), 'warning');
    });

    test('topic is coalesced to null', done => {
      sandbox.stub(element, '_changeChanged');
      sandbox.stub(element.$.restAPI, 'getChangeDetail', () => {
        return Promise.resolve({
          id: '123456789',
          labels: {},
          current_revision: 'foo',
          revisions: {foo: {commit: {}}},
        });
      });

      element._getChangeDetail().then(() => {
        assert.isNull(element._change.topic);
        done();
      });
    });

    test('commit sha is populated from getChangeDetail', done => {
      sandbox.stub(element, '_changeChanged');
      sandbox.stub(element.$.restAPI, 'getChangeDetail', () => {
        return Promise.resolve({
          id: '123456789',
          labels: {},
          current_revision: 'foo',
          revisions: {foo: {commit: {}}},
        });
      });

      element._getChangeDetail().then(() => {
        assert.equal('foo', element._commitInfo.commit);
        done();
      });
    });

    test('edit is added to change', () => {
      sandbox.stub(element, '_changeChanged');
      sandbox.stub(element.$.restAPI, 'getChangeDetail', () => {
        return Promise.resolve({
          id: '123456789',
          labels: {},
          current_revision: 'foo',
          revisions: {foo: {commit: {}}},
        });
      });
      sandbox.stub(element, '_getEdit', () => {
        return Promise.resolve({
          base_patch_set_number: 1,
          commit: {commit: 'bar'},
        });
      });
      element._patchRange = {};

      return element._getChangeDetail().then(() => {
        const revs = element._change.revisions;
        assert.equal(Object.keys(revs).length, 2);
        assert.deepEqual(revs['foo'], {commit: {commit: 'foo'}});
        assert.deepEqual(revs['bar'], {
          _number: element.EDIT_NAME,
          basePatchNum: 1,
          commit: {commit: 'bar'},
          fetch: undefined,
        });
      });
    });

    test('_getBasePatchNum', () => {
      const _change = {
        _number: 42,
        revisions: {
          '98da160735fb81604b4c40e93c368f380539dd0e': {
            _number: 1,
            commit: {
              parents: [],
            },
          },
        },
      };
      const _patchRange = {
        basePatchNum: 'PARENT',
      };
      assert.equal(element._getBasePatchNum(_change, _patchRange), 'PARENT');

      element._prefs = {
        default_base_for_merges: 'FIRST_PARENT',
      };

      const _change2 = {
        _number: 42,
        revisions: {
          '98da160735fb81604b4c40e93c368f380539dd0e': {
            _number: 1,
            commit: {
              parents: [
                {
                  commit: '6e12bdf1176eb4ab24d8491ba3b6d0704409cde8',
                  subject: 'test',
                },
                {
                  commit: '22f7db4754b5d9816fc581f3d9a6c0ef8429c841',
                  subject: 'test3',
                },
              ],
            },
          },
        },
      };
      assert.equal(element._getBasePatchNum(_change2, _patchRange), -1);

      _patchRange.patchNum = 1;
      assert.equal(element._getBasePatchNum(_change2, _patchRange), 'PARENT');
    });

    test('_openReplyDialog called with `ANY` when coming from tap event',
        () => {
          const openStub = sandbox.stub(element, '_openReplyDialog');
          element._serverConfig = {};
          MockInteractions.tap(element.$.replyBtn);
          assert(openStub.lastCall.calledWithExactly(
              element.$.replyDialog.FocusTarget.ANY),
          '_openReplyDialog should have been passed ANY');
          assert.equal(openStub.callCount, 1);
        });

    test('_openReplyDialog called with `BODY` when coming from message reply' +
        'event', done => {
      flush(() => {
        const openStub = sandbox.stub(element, '_openReplyDialog');
        element.messagesList.fire('reply',
            {message: {message: 'text'}});
        assert(openStub.lastCall.calledWithExactly(
            element.$.replyDialog.FocusTarget.BODY),
        '_openReplyDialog should have been passed BODY');
        assert.equal(openStub.callCount, 1);
        done();
      });
    });

    test('reply dialog focus can be controlled', () => {
      const FocusTarget = element.$.replyDialog.FocusTarget;
      const openStub = sandbox.stub(element, '_openReplyDialog');

      const e = {detail: {}};
      element._handleShowReplyDialog(e);
      assert(openStub.lastCall.calledWithExactly(FocusTarget.REVIEWERS),
          '_openReplyDialog should have been passed REVIEWERS');
      assert.equal(openStub.callCount, 1);

      e.detail.value = {ccsOnly: true};
      element._handleShowReplyDialog(e);
      assert(openStub.lastCall.calledWithExactly(FocusTarget.CCS),
          '_openReplyDialog should have been passed CCS');
      assert.equal(openStub.callCount, 2);
    });

    test('getUrlParameter functionality', () => {
      const locationStub = sandbox.stub(element, '_getLocationSearch');

      locationStub.returns('?test');
      assert.equal(element._getUrlParameter('test'), 'test');
      locationStub.returns('?test2=12&test=3');
      assert.equal(element._getUrlParameter('test'), 'test');
      locationStub.returns('');
      assert.isNull(element._getUrlParameter('test'));
      locationStub.returns('?');
      assert.isNull(element._getUrlParameter('test'));
      locationStub.returns('?test2');
      assert.isNull(element._getUrlParameter('test'));
    });

    test('revert dialog opened with revert param', done => {
      sandbox.stub(element.$.restAPI, 'getLoggedIn', () => {
        return Promise.resolve(true);
      });
      sandbox.stub(Gerrit, 'awaitPluginsLoaded', () => {
        return Promise.resolve();
      });

      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: 2,
      };
      element._change = {
        change_id: 'Iad9dc96274af6946f3632be53b106ef80f7ba6ca',
        revisions: {
          rev1: {_number: 1, commit: {parents: []}},
          rev2: {_number: 2, commit: {parents: []}},
        },
        current_revision: 'rev1',
        status: element.ChangeStatus.MERGED,
        labels: {},
        actions: {},
      };

      sandbox.stub(element, '_getUrlParameter',
          param => {
            assert.equal(param, 'revert');
            return param;
          });

      sandbox.stub(element.$.actions, 'showRevertDialog',
          done);

      element._maybeShowRevertDialog();
      assert.isTrue(Gerrit.awaitPluginsLoaded.called);
    });

    suite('scroll related tests', () => {
      test('document scrolling calls function to set scroll height', done => {
        const originalHeight = document.body.scrollHeight;
        const scrollStub = sandbox.stub(element, '_handleScroll',
            () => {
              assert.isTrue(scrollStub.called);
              document.body.style.height = originalHeight + 'px';
              scrollStub.restore();
              done();
            });
        document.body.style.height = '10000px';
        element._handleScroll();
      });

      test('scrollTop is set correctly', () => {
        element.viewState = {scrollTop: TEST_SCROLL_TOP_PX};

        sandbox.stub(element, '_reload', () => {
          // When element is reloaded, ensure that the history
          // state has the scrollTop set earlier. This will then
          // be reset.
          assert.isTrue(element.viewState.scrollTop == TEST_SCROLL_TOP_PX);
          return Promise.resolve({});
        });

        // simulate reloading component, which is done when route
        // changes to match a regex of change view type.
        element._paramsChanged({view: Gerrit.Nav.View.CHANGE});
      });

      test('scrollTop is reset when new change is loaded', () => {
        element._resetFileListViewState();
        assert.equal(element.viewState.scrollTop, 0);
      });
    });

    suite('reply dialog tests', () => {
      setup(() => {
        sandbox.stub(element.$.replyDialog, '_draftChanged');
        sandbox.stub(element.$.replyDialog, 'fetchChangeUpdates',
            () => { return Promise.resolve({isLatest: true}); });
        element._change = {labels: {}};
      });

      test('reply from comment adds quote text', () => {
        const e = {detail: {message: {message: 'quote text'}}};
        element._handleMessageReply(e);
        assert.equal(element.$.replyDialog.quote, '> quote text\n\n');
      });

      test('reply from comment replaces quote text', () => {
        element.$.replyDialog.draft = '> old quote text\n\n some draft text';
        element.$.replyDialog.quote = '> old quote text\n\n';
        const e = {detail: {message: {message: 'quote text'}}};
        element._handleMessageReply(e);
        assert.equal(element.$.replyDialog.quote, '> quote text\n\n');
      });

      test('reply from same comment preserves quote text', () => {
        element.$.replyDialog.draft = '> quote text\n\n some draft text';
        element.$.replyDialog.quote = '> quote text\n\n';
        const e = {detail: {message: {message: 'quote text'}}};
        element._handleMessageReply(e);
        assert.equal(element.$.replyDialog.draft,
            '> quote text\n\n some draft text');
        assert.equal(element.$.replyDialog.quote, '> quote text\n\n');
      });

      test('reply from top of page contains previous draft', () => {
        const div = document.createElement('div');
        element.$.replyDialog.draft = '> quote text\n\n some draft text';
        element.$.replyDialog.quote = '> quote text\n\n';
        const e = {target: div, preventDefault: sandbox.spy()};
        element._handleReplyTap(e);
        assert.equal(element.$.replyDialog.draft,
            '> quote text\n\n some draft text');
        assert.equal(element.$.replyDialog.quote, '> quote text\n\n');
      });
    });

    test('reply button is disabled until server config is loaded', () => {
      assert.isTrue(element._replyDisabled);
      element._serverConfig = {};
      assert.isFalse(element._replyDisabled);
    });

    suite('commit message expand/collapse', () => {
      setup(() => {
        sandbox.stub(element, 'fetchChangeUpdates',
            () => { return Promise.resolve({isLatest: false}); });
      });

      test('commitCollapseToggle hidden for short commit message', () => {
        element._latestCommitMessage = '';
        assert.isTrue(element.$.commitCollapseToggle.hasAttribute('hidden'));
      });

      test('commitCollapseToggle shown for long commit message', () => {
        element._latestCommitMessage = _.times(31, String).join('\n');
        assert.isFalse(element.$.commitCollapseToggle.hasAttribute('hidden'));
      });

      test('commitCollapseToggle functions', () => {
        element._latestCommitMessage = _.times(31, String).join('\n');
        assert.isTrue(element._commitCollapsed);
        assert.isTrue(
            element.$.commitMessage.classList.contains('collapsed'));
        MockInteractions.tap(element.$.commitCollapseToggleButton);
        assert.isFalse(element._commitCollapsed);
        assert.isFalse(
            element.$.commitMessage.classList.contains('collapsed'));
      });
    });

    suite('related changes expand/collapse', () => {
      let updateHeightSpy;
      setup(() => {
        updateHeightSpy = sandbox.spy(element, '_updateRelatedChangeMaxHeight');
      });

      test('relatedChangesToggle shown height greater than changeInfo height',
          () => {
            assert.isFalse(element.$.relatedChangesToggle.classList
                .contains('showToggle'));
            sandbox.stub(element, '_getOffsetHeight', () => 50);
            sandbox.stub(element, '_getScrollHeight', () => 60);
            sandbox.stub(element, '_getLineHeight', () => 5);
            sandbox.stub(window, 'matchMedia', () => ({matches: true}));
            element.$.relatedChanges.dispatchEvent(
                new CustomEvent('new-section-loaded'));
            assert.isTrue(element.$.relatedChangesToggle.classList
                .contains('showToggle'));
            assert.equal(updateHeightSpy.callCount, 1);
          });

      test('relatedChangesToggle hidden height less than changeInfo height',
          () => {
            assert.isFalse(element.$.relatedChangesToggle.classList
                .contains('showToggle'));
            sandbox.stub(element, '_getOffsetHeight', () => 50);
            sandbox.stub(element, '_getScrollHeight', () => 40);
            sandbox.stub(element, '_getLineHeight', () => 5);
            sandbox.stub(window, 'matchMedia', () => ({matches: true}));
            element.$.relatedChanges.dispatchEvent(
                new CustomEvent('new-section-loaded'));
            assert.isFalse(element.$.relatedChangesToggle.classList
                .contains('showToggle'));
            assert.equal(updateHeightSpy.callCount, 1);
          });

      test('relatedChangesToggle functions', () => {
        sandbox.stub(element, '_getOffsetHeight', () => 50);
        sandbox.stub(window, 'matchMedia', () => ({matches: false}));
        element._relatedChangesLoading = false;
        assert.isTrue(element._relatedChangesCollapsed);
        assert.isTrue(
            element.$.relatedChanges.classList.contains('collapsed'));
        MockInteractions.tap(element.$.relatedChangesToggleButton);
        assert.isFalse(element._relatedChangesCollapsed);
        assert.isFalse(
            element.$.relatedChanges.classList.contains('collapsed'));
      });

      test('_updateRelatedChangeMaxHeight without commit toggle', () => {
        sandbox.stub(element, '_getOffsetHeight', () => 50);
        sandbox.stub(element, '_getLineHeight', () => 12);
        sandbox.stub(window, 'matchMedia', () => ({matches: false}));

        // 50 (existing height) - 30 (extra height) = 20 (adjusted height).
        // 20 (max existing height)  % 12 (line height) = 6 (remainder).
        // 20 (adjusted height) - 8 (remainder) = 12 (max height to set).

        element._updateRelatedChangeMaxHeight();
        assert.equal(getCustomCssValue('--relation-chain-max-height'),
            '12px');
        assert.equal(getCustomCssValue('--related-change-btn-top-padding'),
            '');
      });

      test('_updateRelatedChangeMaxHeight with commit toggle', () => {
        element._latestCommitMessage = _.times(31, String).join('\n');
        sandbox.stub(element, '_getOffsetHeight', () => 50);
        sandbox.stub(element, '_getLineHeight', () => 12);
        sandbox.stub(window, 'matchMedia', () => ({matches: false}));

        // 50 (existing height) % 12 (line height) = 2 (remainder).
        // 50 (existing height)  - 2 (remainder) = 48 (max height to set).

        element._updateRelatedChangeMaxHeight();
        assert.equal(getCustomCssValue('--relation-chain-max-height'),
            '48px');
        assert.equal(getCustomCssValue('--related-change-btn-top-padding'),
            '2px');
      });

      test('_updateRelatedChangeMaxHeight in small screen mode', () => {
        element._latestCommitMessage = _.times(31, String).join('\n');
        sandbox.stub(element, '_getOffsetHeight', () => 50);
        sandbox.stub(element, '_getLineHeight', () => 12);
        sandbox.stub(window, 'matchMedia', () => ({matches: true}));

        element._updateRelatedChangeMaxHeight();

        // 400 (new height) % 12 (line height) = 4 (remainder).
        // 400 (new height) - 4 (remainder) = 396.

        assert.equal(getCustomCssValue('--relation-chain-max-height'),
            '396px');
      });

      test('_updateRelatedChangeMaxHeight in medium screen mode', () => {
        element._latestCommitMessage = _.times(31, String).join('\n');
        sandbox.stub(element, '_getOffsetHeight', () => 50);
        sandbox.stub(element, '_getLineHeight', () => 12);
        sandbox.stub(window, 'matchMedia', () => {
          if (window.matchMedia.lastCall.args[0] === '(max-width: 75em)') {
            return {matches: true};
          } else {
            return {matches: false};
          }
        });

        // 100 (new height) % 12 (line height) = 4 (remainder).
        // 100 (new height) - 4 (remainder) = 96.
        element._updateRelatedChangeMaxHeight();
        assert.equal(getCustomCssValue('--relation-chain-max-height'),
            '96px');
      });


      suite('update checks', () => {
        setup(() => {
          sandbox.spy(element, '_startUpdateCheckTimer');
          sandbox.stub(element, 'async', f => {
            // Only fire the async callback one time.
            if (element.async.callCount > 1) { return; }
            f.call(element);
          });
        });

        test('_startUpdateCheckTimer negative delay', () => {
          sandbox.stub(element, 'fetchChangeUpdates');

          element._serverConfig = {change: {update_delay: -1}};

          assert.isTrue(element._startUpdateCheckTimer.called);
          assert.isFalse(element.fetchChangeUpdates.called);
        });

        test('_startUpdateCheckTimer up-to-date', () => {
          sandbox.stub(element, 'fetchChangeUpdates',
              () => { return Promise.resolve({isLatest: true}); });

          element._serverConfig = {change: {update_delay: 12345}};

          assert.isTrue(element._startUpdateCheckTimer.called);
          assert.isTrue(element.fetchChangeUpdates.called);
          assert.equal(element.async.lastCall.args[1], 12345 * 1000);
        });

        test('_startUpdateCheckTimer out-of-date shows an alert', done => {
          sandbox.stub(element, 'fetchChangeUpdates',
              () => { return Promise.resolve({isLatest: false}); });
          element.addEventListener('show-alert', e => {
            assert.equal(e.detail.message,
                'A newer patch set has been uploaded');
            done();
          });
          element._serverConfig = {change: {update_delay: 12345}};
        });

        test('_startUpdateCheckTimer new status shows an alert', done => {
          sandbox.stub(element, 'fetchChangeUpdates')
              .returns(Promise.resolve({
                isLatest: true,
                newStatus: element.ChangeStatus.MERGED,
              }));
          element.addEventListener('show-alert', e => {
            assert.equal(e.detail.message, 'This change has been merged');
            done();
          });
          element._serverConfig = {change: {update_delay: 12345}};
        });

        test('_startUpdateCheckTimer new messages shows an alert', done => {
          sandbox.stub(element, 'fetchChangeUpdates')
              .returns(Promise.resolve({
                isLatest: true,
                newMessages: true,
              }));
          element.addEventListener('show-alert', e => {
            assert.equal(e.detail.message,
                'There are new messages on this change');
            done();
          });
          element._serverConfig = {change: {update_delay: 12345}};
        });
      });

      test('canStartReview computation', () => {
        const change1 = {};
        const change2 = {
          actions: {
            ready: {
              enabled: true,
            },
          },
        };
        const change3 = {
          actions: {
            ready: {
              label: 'Ready for Review',
            },
          },
        };
        assert.isFalse(element._computeCanStartReview(change1));
        assert.isTrue(element._computeCanStartReview(change2));
        assert.isFalse(element._computeCanStartReview(change3));
      });
    });

    test('header class computation', () => {
      assert.equal(element._computeHeaderClass(), 'header');
      assert.equal(element._computeHeaderClass(true), 'header editMode');
    });

    test('_maybeScrollToMessage', done => {
      flush(() => {
        const scrollStub = sandbox.stub(element.messagesList,
            'scrollToMessage');

        element._maybeScrollToMessage('');
        assert.isFalse(scrollStub.called);
        element._maybeScrollToMessage('message');
        assert.isFalse(scrollStub.called);
        element._maybeScrollToMessage('#message-TEST');
        assert.isTrue(scrollStub.called);
        assert.equal(scrollStub.lastCall.args[0], 'TEST');
        done();
      });
    });

    test('topic update reloads related changes', () => {
      sandbox.stub(element.$.relatedChanges, 'reload');
      element.dispatchEvent(new CustomEvent('topic-changed'));
      assert.isTrue(element.$.relatedChanges.reload.calledOnce);
    });

    test('_computeEditMode', () => {
      const callCompute = (range, params) =>
        element._computeEditMode({base: range}, {base: params});
      assert.isFalse(callCompute({}, {}));
      assert.isTrue(callCompute({}, {edit: true}));
      assert.isFalse(callCompute({basePatchNum: 'PARENT', patchNum: 1}, {}));
      assert.isFalse(callCompute({basePatchNum: 'edit', patchNum: 1}, {}));
      assert.isTrue(callCompute({basePatchNum: 1, patchNum: 'edit'}, {}));
    });

    test('_processEdit', () => {
      element._patchRange = {};
      const change = {
        current_revision: 'foo',
        revisions: {foo: {commit: {}, actions: {cherrypick: {enabled: true}}}},
      };
      let mockChange;

      // With no edit, mockChange should be unmodified.
      element._processEdit(mockChange = _.cloneDeep(change), null);
      assert.deepEqual(mockChange, change);

      // When edit is not based on the latest PS, current_revision should be
      // unmodified.
      const edit = {
        base_patch_set_number: 1,
        commit: {commit: 'bar'},
        fetch: true,
      };
      element._processEdit(mockChange = _.cloneDeep(change), edit);
      assert.notDeepEqual(mockChange, change);
      assert.equal(mockChange.revisions.bar._number, element.EDIT_NAME);
      assert.equal(mockChange.current_revision, change.current_revision);
      assert.deepEqual(mockChange.revisions.bar.commit, {commit: 'bar'});
      assert.notOk(mockChange.revisions.bar.actions);

      edit.base_revision = 'foo';
      element._processEdit(mockChange = _.cloneDeep(change), edit);
      assert.notDeepEqual(mockChange, change);
      assert.equal(mockChange.current_revision, 'bar');
      assert.deepEqual(mockChange.revisions.bar.actions,
          mockChange.revisions.foo.actions);

      // If _patchRange.patchNum is defined, do not load edit.
      element._patchRange.patchNum = 'baz';
      change.current_revision = 'baz';
      element._processEdit(mockChange = _.cloneDeep(change), edit);
      assert.equal(element._patchRange.patchNum, 'baz');
      assert.notOk(mockChange.revisions.bar.actions);
    });

    test('file-action-tap handling', () => {
      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: 1,
      };
      const fileList = element.$.fileList;
      const Actions = GrEditConstants.Actions;
      const controls = element.$.fileListHeader.$.editControls;
      sandbox.stub(controls, 'openDeleteDialog');
      sandbox.stub(controls, 'openRenameDialog');
      sandbox.stub(controls, 'openRestoreDialog');
      sandbox.stub(Gerrit.Nav, 'getEditUrlForDiff');
      sandbox.stub(Gerrit.Nav, 'navigateToRelativeUrl');

      // Delete
      fileList.dispatchEvent(new CustomEvent('file-action-tap',
          {detail: {action: Actions.DELETE.id, path: 'foo'}, bubbles: true}));
      flushAsynchronousOperations();

      assert.isTrue(controls.openDeleteDialog.called);
      assert.equal(controls.openDeleteDialog.lastCall.args[0], 'foo');

      // Restore
      fileList.dispatchEvent(new CustomEvent('file-action-tap',
          {detail: {action: Actions.RESTORE.id, path: 'foo'}, bubbles: true}));
      flushAsynchronousOperations();

      assert.isTrue(controls.openRestoreDialog.called);
      assert.equal(controls.openRestoreDialog.lastCall.args[0], 'foo');

      // Rename
      fileList.dispatchEvent(new CustomEvent('file-action-tap',
          {detail: {action: Actions.RENAME.id, path: 'foo'}, bubbles: true}));
      flushAsynchronousOperations();

      assert.isTrue(controls.openRenameDialog.called);
      assert.equal(controls.openRenameDialog.lastCall.args[0], 'foo');

      // Open
      fileList.dispatchEvent(new CustomEvent('file-action-tap',
          {detail: {action: Actions.OPEN.id, path: 'foo'}, bubbles: true}));
      flushAsynchronousOperations();

      assert.isTrue(Gerrit.Nav.getEditUrlForDiff.called);
      assert.equal(Gerrit.Nav.getEditUrlForDiff.lastCall.args[1], 'foo');
      assert.equal(Gerrit.Nav.getEditUrlForDiff.lastCall.args[2], '1');
      assert.isTrue(Gerrit.Nav.navigateToRelativeUrl.called);
    });

    test('_selectedRevision updates when patchNum is changed', () => {
      const revision1 = {_number: 1, commit: {parents: []}};
      const revision2 = {_number: 2, commit: {parents: []}};
      sandbox.stub(element.$.restAPI, 'getChangeDetail').returns(
          Promise.resolve({
            revisions: {
              aaa: revision1,
              bbb: revision2,
            },
            labels: {},
            actions: {},
            current_revision: 'bbb',
            change_id: 'loremipsumdolorsitamet',
          }));
      sandbox.stub(element, '_getEdit').returns(Promise.resolve());
      sandbox.stub(element, '_getPreferences').returns(Promise.resolve({}));
      element._patchRange = {patchNum: '2'};
      return element._getChangeDetail().then(() => {
        assert.strictEqual(element._selectedRevision, revision2);

        element.set('_patchRange.patchNum', '1');
        assert.strictEqual(element._selectedRevision, revision1);
      });
    });

    test('_sendShowChangeEvent', () => {
      element._change = {labels: {}};
      element._patchRange = {patchNum: 4};
      element._mergeable = true;
      const showStub = sandbox.stub(element.$.jsAPI, 'handleEvent');
      element._sendShowChangeEvent();
      assert.isTrue(showStub.calledOnce);
      assert.equal(
          showStub.lastCall.args[0], element.$.jsAPI.EventType.SHOW_CHANGE);
      assert.deepEqual(showStub.lastCall.args[1], {
        change: {labels: {}},
        patchNum: 4,
        info: {mergeable: true},
      });
    });

    suite('_handleEditTap', () => {
      let fireEdit;

      setup(() => {
        fireEdit = () => {
          element.$.actions.dispatchEvent(new CustomEvent('edit-tap'));
        };
        navigateToChangeStub.restore();

        element._change = {revisions: {rev1: {_number: 1}}};
      });

      test('edit exists in revisions', done => {
        sandbox.stub(Gerrit.Nav, 'navigateToChange', (...args) => {
          assert.equal(args.length, 2);
          assert.equal(args[1], element.EDIT_NAME); // patchNum
          done();
        });

        element.set('_change.revisions.rev2', {_number: element.EDIT_NAME});
        flushAsynchronousOperations();

        fireEdit();
      });

      test('no edit exists in revisions, non-latest patchset', done => {
        sandbox.stub(Gerrit.Nav, 'navigateToChange', (...args) => {
          assert.equal(args.length, 4);
          assert.equal(args[1], 1); // patchNum
          assert.equal(args[3], true); // opt_isEdit
          done();
        });

        element.set('_change.revisions.rev2', {_number: 2});
        element._patchRange = {patchNum: 1};
        flushAsynchronousOperations();

        fireEdit();
      });

      test('no edit exists in revisions, latest patchset', done => {
        sandbox.stub(Gerrit.Nav, 'navigateToChange', (...args) => {
          assert.equal(args.length, 4);
          // No patch should be specified when patchNum == latest.
          assert.isNotOk(args[1]); // patchNum
          assert.equal(args[3], true); // opt_isEdit
          done();
        });

        element.set('_change.revisions.rev2', {_number: 2});
        element._patchRange = {patchNum: 2};
        flushAsynchronousOperations();

        fireEdit();
      });
    });

    test('_handleStopEditTap', done => {
      sandbox.stub(element.$.metadata, '_computeLabelNames');
      navigateToChangeStub.restore();
      sandbox.stub(element, 'computeLatestPatchNum').returns(1);
      sandbox.stub(Gerrit.Nav, 'navigateToChange', (...args) => {
        assert.equal(args.length, 2);
        assert.equal(args[1], 1); // patchNum
        done();
      });

      element._patchRange = {patchNum: 1};
      element.$.actions.dispatchEvent(new CustomEvent('stop-edit-tap',
          {bubbles: false}));
    });

    suite('plugin endpoints', () => {
      test('endpoint params', done => {
        element._change = {labels: {}};
        element._selectedRevision = {};
        let hookEl;
        let plugin;
        Gerrit.install(
            p => {
              plugin = p;
              plugin.hook('change-view-integration').getLastAttached().then(
                  el => hookEl = el);
            },
            '0.1',
            'http://some/plugins/url.html');
        flush(() => {
          assert.strictEqual(hookEl.plugin, plugin);
          assert.strictEqual(hookEl.change, element._change);
          assert.strictEqual(hookEl.revision, element._selectedRevision);
          done();
        });
      });
    });

    suite('_getMergeability', () => {
      let getMergeableStub;

      setup(() => {
        element._change = {labels: {}};
        getMergeableStub = sandbox.stub(element.$.restAPI, 'getMergeable')
            .returns(Promise.resolve({mergeable: true}));
      });

      test('merged change', () => {
        element._mergeable = null;
        element._change.status = element.ChangeStatus.MERGED;
        return element._getMergeability().then(() => {
          assert.isFalse(element._mergeable);
          assert.isFalse(getMergeableStub.called);
        });
      });

      test('abandoned change', () => {
        element._mergeable = null;
        element._change.status = element.ChangeStatus.ABANDONED;
        return element._getMergeability().then(() => {
          assert.isFalse(element._mergeable);
          assert.isFalse(getMergeableStub.called);
        });
      });

      test('open change', () => {
        element._mergeable = null;
        return element._getMergeability().then(() => {
          assert.isTrue(element._mergeable);
          assert.isTrue(getMergeableStub.called);
        });
      });
    });

    test('_paramsChanged sets in projectLookup', () => {
      sandbox.stub(element.$.relatedChanges, 'reload');
      sandbox.stub(element, '_reload').returns(Promise.resolve());
      const setStub = sandbox.stub(element.$.restAPI, 'setInProjectLookup');
      element._paramsChanged({
        view: Gerrit.Nav.View.CHANGE,
        changeNum: 101,
        project: 'test-project',
      });
      assert.isTrue(setStub.calledOnce);
      assert.isTrue(setStub.calledWith(101, 'test-project'));
    });

    test('_handleToggleStar called when star is tapped', () => {
      element._change = {
        owner: {_account_id: 1},
        starred: false,
      };
      element._loggedIn = true;
      const stub = sandbox.stub(element, '_handleToggleStar');
      flushAsynchronousOperations();

      MockInteractions.tap(element.$.changeStar.$$('button'));
      assert.isTrue(stub.called);
    });
  });
</script>