<!DOCTYPE html>
<!--
@license
Copyright (C) 2015 The Android Open Source Project

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->

<meta name="viewport" content="width=device-width, minimum-scale=1.0, initial-scale=1.0, user-scalable=yes">
<title>gr-diff-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>
<script src="../../../scripts/util.js"></script>

<link rel="import" href="gr-diff-view.html">

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

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

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

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

    const PARENT = 'PARENT';

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

      stub('gr-rest-api-interface', {
        getConfig() { return Promise.resolve({change: {}}); },
        getLoggedIn() { return Promise.resolve(false); },
        getProjectConfig() { return Promise.resolve({}); },
        getDiffChangeDetail() { return Promise.resolve({}); },
        getChangeFiles() { return Promise.resolve({}); },
        saveFileReviewed() { return Promise.resolve(); },
        getDiffComments() { return Promise.resolve({}); },
        getDiffRobotComments() { return Promise.resolve({}); },
        getDiffDrafts() { return Promise.resolve({}); },
        getReviewedFiles() { return Promise.resolve([]); },
      });
      element = fixture('basic');
      return element._loadComments();
    });

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

    test('params change triggers diffViewDisplayed()', () => {
      sandbox.stub(element.$.reporting, 'diffViewDisplayed');
      sandbox.stub(element.$.diffHost, 'reload').returns(Promise.resolve());
      sandbox.spy(element, '_paramsChanged');
      element.params = {
        view: Gerrit.Nav.View.DIFF,
        changeNum: '42',
        patchNum: '2',
        basePatchNum: '1',
        path: '/COMMIT_MSG',
      };

      return element._paramsChanged.returnValues[0].then(() => {
        assert.isTrue(element.$.reporting.diffViewDisplayed.calledOnce);
      });
    });

    test('toggle left diff with a hotkey', () => {
      const toggleLeftDiffStub = sandbox.stub(
          element.$.diffHost, 'toggleLeftDiff');
      MockInteractions.pressAndReleaseKeyOn(element, 65, 'shift', 'a');
      assert.isTrue(toggleLeftDiffStub.calledOnce);
    });

    test('keyboard shortcuts', () => {
      element._changeNum = '42';
      element._patchRange = {
        basePatchNum: PARENT,
        patchNum: '10',
      };
      element._change = {
        _number: 42,
        revisions: {
          a: {_number: 10, commit: {parents: []}},
        },
      };
      element._fileList = ['chell.go', 'glados.txt', 'wheatley.md'];
      element._path = 'glados.txt';
      element.changeViewState.selectedFileIndex = 1;

      const diffNavStub = sandbox.stub(Gerrit.Nav, 'navigateToDiff');
      const changeNavStub = sandbox.stub(Gerrit.Nav, 'navigateToChange');

      MockInteractions.pressAndReleaseKeyOn(element, 85, null, 'u');
      assert(changeNavStub.lastCall.calledWith(element._change),
          'Should navigate to /c/42/');

      MockInteractions.pressAndReleaseKeyOn(element, 221, null, ']');
      assert(diffNavStub.lastCall.calledWith(element._change, 'wheatley.md',
          '10', PARENT), 'Should navigate to /c/42/10/wheatley.md');
      element._path = 'wheatley.md';
      assert.equal(element.changeViewState.selectedFileIndex, 2);
      assert.isTrue(element._loading);

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert(diffNavStub.lastCall.calledWith(element._change, 'glados.txt',
          '10', PARENT), 'Should navigate to /c/42/10/glados.txt');
      element._path = 'glados.txt';
      assert.equal(element.changeViewState.selectedFileIndex, 1);
      assert.isTrue(element._loading);

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert(diffNavStub.lastCall.calledWith(element._change, 'chell.go', '10',
          PARENT), 'Should navigate to /c/42/10/chell.go');
      element._path = 'chell.go';
      assert.equal(element.changeViewState.selectedFileIndex, 0);
      assert.isTrue(element._loading);

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert(changeNavStub.lastCall.calledWith(element._change),
          'Should navigate to /c/42/');
      assert.equal(element.changeViewState.selectedFileIndex, 0);
      assert.isTrue(element._loading);

      const showPrefsStub =
          sandbox.stub(element.$.diffPreferences.$.prefsOverlay, 'open',
              () => Promise.resolve());

      MockInteractions.pressAndReleaseKeyOn(element, 188, null, ',');
      assert(showPrefsStub.calledOnce);

      let scrollStub = sandbox.stub(element.$.cursor, 'moveToNextChunk');
      MockInteractions.pressAndReleaseKeyOn(element, 78, null, 'n');
      assert(scrollStub.calledOnce);

      scrollStub = sandbox.stub(element.$.cursor, 'moveToPreviousChunk');
      MockInteractions.pressAndReleaseKeyOn(element, 80, null, 'p');
      assert(scrollStub.calledOnce);

      scrollStub = sandbox.stub(element.$.cursor, 'moveToNextCommentThread');
      MockInteractions.pressAndReleaseKeyOn(element, 78, 'shift', 'n');
      assert(scrollStub.calledOnce);

      scrollStub = sandbox.stub(element.$.cursor,
          'moveToPreviousCommentThread');
      MockInteractions.pressAndReleaseKeyOn(element, 80, 'shift', 'p');
      assert(scrollStub.calledOnce);

      const computeContainerClassStub = sandbox.stub(element.$.diffHost.$.diff,
          '_computeContainerClass');
      MockInteractions.pressAndReleaseKeyOn(element, 74, null, 'j');
      assert(computeContainerClassStub.lastCall.calledWithExactly(
          false, 'SIDE_BY_SIDE', true));

      MockInteractions.pressAndReleaseKeyOn(element, 27, null, 'esc');
      assert(computeContainerClassStub.lastCall.calledWithExactly(
          false, 'SIDE_BY_SIDE', false));

      sandbox.stub(element, '_setReviewed');
      element.$.reviewed.checked = false;
      MockInteractions.pressAndReleaseKeyOn(element, 82, 'shift', 'r');
      assert.isFalse(element._setReviewed.called);

      MockInteractions.pressAndReleaseKeyOn(element, 82, null, 'r');
      assert.isTrue(element._setReviewed.called);
      assert.equal(element._setReviewed.lastCall.args[0], true);
    });

    test('shift+x shortcut expands all diff context', () => {
      const expandStub = sandbox.stub(element.$.diffHost, 'expandAllContext');
      MockInteractions.pressAndReleaseKeyOn(element, 88, 'shift', 'x');
      flushAsynchronousOperations();
      assert.isTrue(expandStub.called);
    });

    test('keyboard shortcuts with patch range', () => {
      element._changeNum = '42';
      element._patchRange = {
        basePatchNum: '5',
        patchNum: '10',
      };
      element._change = {
        _number: 42,
        revisions: {
          a: {_number: 10, commit: {parents: []}},
          b: {_number: 5, commit: {parents: []}},
        },
      };
      element._fileList = ['chell.go', 'glados.txt', 'wheatley.md'];
      element._path = 'glados.txt';

      const diffNavStub = sandbox.stub(Gerrit.Nav, 'navigateToDiff');
      const changeNavStub = sandbox.stub(Gerrit.Nav, 'navigateToChange');

      MockInteractions.pressAndReleaseKeyOn(element, 65, null, 'a');
      assert.isTrue(changeNavStub.notCalled, 'The `a` keyboard shortcut ' +
          'should only work when the user is logged in.');
      assert.isNull(window.sessionStorage.getItem(
          'changeView.showReplyDialog'));

      element._loggedIn = true;
      MockInteractions.pressAndReleaseKeyOn(element, 65, null, 'a');
      assert.isTrue(element.changeViewState.showReplyDialog);

      assert(changeNavStub.lastCall.calledWithExactly(element._change, '10',
          '5'), 'Should navigate to /c/42/5..10');

      MockInteractions.pressAndReleaseKeyOn(element, 85, null, 'u');
      assert(changeNavStub.lastCall.calledWithExactly(element._change, '10',
          '5'), 'Should navigate to /c/42/5..10');

      MockInteractions.pressAndReleaseKeyOn(element, 221, null, ']');
      assert.isTrue(element._loading);
      assert(diffNavStub.lastCall.calledWithExactly(element._change,
          'wheatley.md', '10', '5'),
          'Should navigate to /c/42/5..10/wheatley.md');
      element._path = 'wheatley.md';

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert.isTrue(element._loading);
      assert(diffNavStub.lastCall.calledWithExactly(element._change,
          'glados.txt', '10', '5'),
          'Should navigate to /c/42/5..10/glados.txt');
      element._path = 'glados.txt';

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert.isTrue(element._loading);
      assert(diffNavStub.lastCall.calledWithExactly(element._change, 'chell.go',
          '10', '5'),
          'Should navigate to /c/42/5..10/chell.go');
      element._path = 'chell.go';

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert.isTrue(element._loading);
      assert(changeNavStub.lastCall.calledWithExactly(element._change, '10',
          '5'),
          'Should navigate to /c/42/5..10');
    });

    test('keyboard shortcuts with old patch number', () => {
      element._changeNum = '42';
      element._patchRange = {
        basePatchNum: PARENT,
        patchNum: '1',
      };
      element._change = {
        _number: 42,
        revisions: {
          a: {_number: 1, commit: {parents: []}},
          b: {_number: 2, commit: {parents: []}},
        },
      };
      element._fileList = ['chell.go', 'glados.txt', 'wheatley.md'];
      element._path = 'glados.txt';

      const diffNavStub = sandbox.stub(Gerrit.Nav, 'navigateToDiff');
      const changeNavStub = sandbox.stub(Gerrit.Nav, 'navigateToChange');

      MockInteractions.pressAndReleaseKeyOn(element, 65, null, 'a');
      assert.isTrue(changeNavStub.notCalled, 'The `a` keyboard shortcut ' +
          'should only work when the user is logged in.');
      assert.isNull(window.sessionStorage.getItem(
          'changeView.showReplyDialog'));

      element._loggedIn = true;
      MockInteractions.pressAndReleaseKeyOn(element, 65, null, 'a');
      assert.isTrue(element.changeViewState.showReplyDialog);

      assert(changeNavStub.lastCall.calledWithExactly(element._change, '1',
          PARENT), 'Should navigate to /c/42/1');

      MockInteractions.pressAndReleaseKeyOn(element, 85, null, 'u');
      assert(changeNavStub.lastCall.calledWithExactly(element._change, '1',
          PARENT), 'Should navigate to /c/42/1');

      MockInteractions.pressAndReleaseKeyOn(element, 221, null, ']');
      assert(diffNavStub.lastCall.calledWithExactly(element._change,
          'wheatley.md', '1', PARENT),
          'Should navigate to /c/42/1/wheatley.md');
      element._path = 'wheatley.md';

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert(diffNavStub.lastCall.calledWithExactly(element._change,
          'glados.txt', '1', PARENT),
          'Should navigate to /c/42/1/glados.txt');
      element._path = 'glados.txt';

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert(diffNavStub.lastCall.calledWithExactly(element._change, 'chell.go',
          '1', PARENT), 'Should navigate to /c/42/1/chell.go');
      element._path = 'chell.go';

      MockInteractions.pressAndReleaseKeyOn(element, 219, null, '[');
      assert(changeNavStub.lastCall.calledWithExactly(element._change, '1',
          PARENT), 'Should navigate to /c/42/1');
    });

    test('Diff preferences hidden when no prefs or logged out', () => {
      element._loggedIn = false;
      flushAsynchronousOperations();
      assert.isTrue(element.$.diffPrefsContainer.hidden);

      element._loggedIn = true;
      flushAsynchronousOperations();
      assert.isTrue(element.$.diffPrefsContainer.hidden);

      element._loggedIn = false;
      element._prefs = {font_size: '12'};
      flushAsynchronousOperations();
      assert.isTrue(element.$.diffPrefsContainer.hidden);

      element._loggedIn = true;
      flushAsynchronousOperations();
      assert.isFalse(element.$.diffPrefsContainer.hidden);
    });

    test('prefsButton opens gr-diff-preferences', () => {
      const handlePrefsTapSpy = sandbox.spy(element, '_handlePrefsTap');
      const overlayOpenStub = sandbox.stub(element.$.diffPreferences,
          'open');
      const prefsButton =
          Polymer.dom(element.root).querySelector('.prefsButton');

      MockInteractions.tap(prefsButton);

      assert.isTrue(handlePrefsTapSpy.called);
      assert.isTrue(overlayOpenStub.called);
    });

    test('_computeCommentString', done => {
      loadCommentSpy = sandbox.spy(element.$.commentAPI, 'loadAll');
      const path = '/test';
      element.$.commentAPI.loadAll().then(comments => {
        const commentCountStub =
            sandbox.stub(comments, 'computeCommentCount');
        const unresolvedCountStub =
            sandbox.stub(comments, 'computeUnresolvedNum');
        commentCountStub.withArgs(1, path).returns(0);
        commentCountStub.withArgs(2, path).returns(1);
        commentCountStub.withArgs(3, path).returns(2);
        commentCountStub.withArgs(4, path).returns(0);
        unresolvedCountStub.withArgs(1, path).returns(1);
        unresolvedCountStub.withArgs(2, path).returns(0);
        unresolvedCountStub.withArgs(3, path).returns(2);
        unresolvedCountStub.withArgs(4, path).returns(0);

        assert.equal(element._computeCommentString(comments, 1, path),
            '1 unresolved');
        assert.equal(element._computeCommentString(comments, 2, path),
            '1 comment');
        assert.equal(element._computeCommentString(comments, 3, path),
            '2 comments, 2 unresolved');
        assert.equal(element._computeCommentString(comments, 4, path), '');
        done();
      });
    });

    suite('url params', () => {
      setup(() => {
        sandbox.stub(Gerrit.Nav, 'getUrlForDiff', (c, p, pn, bpn) => {
          return `${c._number}-${p}-${pn}-${bpn}`;
        });
        sandbox.stub(Gerrit.Nav, 'getUrlForChange', (c, pn, bpn) => {
          return `${c._number}-${pn}-${bpn}`;
        });
      });

      test('_formattedFiles', () => {
        element._changeNum = '42';
        element._patchRange = {
          basePatchNum: PARENT,
          patchNum: '10',
        };
        element._change = {_number: 42};
        element._fileList = ['chell.go', 'glados.txt', 'wheatley.md',
          '/COMMIT_MSG', '/MERGE_LIST'];
        element._path = 'glados.txt';
        const expectedFormattedFiles = [
          {
            text: 'chell.go',
            mobileText: 'chell.go',
            value: 'chell.go',
            bottomText: '',
          }, {
            text: 'glados.txt',
            mobileText: 'glados.txt',
            value: 'glados.txt',
            bottomText: '',
          }, {
            text: 'wheatley.md',
            mobileText: 'wheatley.md',
            value: 'wheatley.md',
            bottomText: '',
          },
          {
            text: 'Commit message',
            mobileText: 'Commit message',
            value: '/COMMIT_MSG',
            bottomText: '',
          },
          {
            text: 'Merge list',
            mobileText: 'Merge list',
            value: '/MERGE_LIST',
            bottomText: '',
          },
        ];

        assert.deepEqual(element._formattedFiles, expectedFormattedFiles);
        assert.equal(element._formattedFiles[1].value, element._path);
      });

      test('prev/up/next links', () => {
        element._changeNum = '42';
        element._patchRange = {
          basePatchNum: PARENT,
          patchNum: '10',
        };
        element._change = {
          _number: 42,
          revisions: {
            a: {_number: 10, commit: {parents: []}},
          },
        };
        element._fileList = ['chell.go', 'glados.txt', 'wheatley.md'];
        element._path = 'glados.txt';
        flushAsynchronousOperations();
        const linkEls = Polymer.dom(element.root).querySelectorAll('.navLink');
        assert.equal(linkEls.length, 3);
        assert.equal(linkEls[0].getAttribute('href'), '42-chell.go-10-PARENT');
        assert.equal(linkEls[1].getAttribute('href'), '42-undefined-undefined');
        assert.equal(linkEls[2].getAttribute('href'),
            '42-wheatley.md-10-PARENT');
        element._path = 'wheatley.md';
        flushAsynchronousOperations();
        assert.equal(linkEls[0].getAttribute('href'),
            '42-glados.txt-10-PARENT');
        assert.equal(linkEls[1].getAttribute('href'), '42-undefined-undefined');
        assert.isFalse(linkEls[2].hasAttribute('href'));
        element._path = 'chell.go';
        flushAsynchronousOperations();
        assert.isFalse(linkEls[0].hasAttribute('href'));
        assert.equal(linkEls[1].getAttribute('href'), '42-undefined-undefined');
        assert.equal(linkEls[2].getAttribute('href'),
            '42-glados.txt-10-PARENT');
        element._path = 'not_a_real_file';
        flushAsynchronousOperations();
        assert.equal(linkEls[0].getAttribute('href'),
            '42-wheatley.md-10-PARENT');
        assert.equal(linkEls[1].getAttribute('href'), '42-undefined-undefined');
        assert.equal(linkEls[2].getAttribute('href'), '42-chell.go-10-PARENT');
      });

      test('prev/up/next links with patch range', () => {
        element._changeNum = '42';
        element._patchRange = {
          basePatchNum: '5',
          patchNum: '10',
        };
        element._change = {
          _number: 42,
          revisions: {
            a: {_number: 5, commit: {parents: []}},
            b: {_number: 10, commit: {parents: []}},
          },
        };
        element._fileList = ['chell.go', 'glados.txt', 'wheatley.md'];
        element._path = 'glados.txt';
        flushAsynchronousOperations();
        const linkEls = Polymer.dom(element.root).querySelectorAll('.navLink');
        assert.equal(linkEls.length, 3);
        assert.equal(linkEls[0].getAttribute('href'), '42-chell.go-10-5');
        assert.equal(linkEls[1].getAttribute('href'), '42-10-5');
        assert.equal(linkEls[2].getAttribute('href'), '42-wheatley.md-10-5');
        element._path = 'wheatley.md';
        flushAsynchronousOperations();
        assert.equal(linkEls[0].getAttribute('href'), '42-glados.txt-10-5');
        assert.equal(linkEls[1].getAttribute('href'), '42-10-5');
        assert.isFalse(linkEls[2].hasAttribute('href'));
        element._path = 'chell.go';
        flushAsynchronousOperations();
        assert.isFalse(linkEls[0].hasAttribute('href'));
        assert.equal(linkEls[1].getAttribute('href'), '42-10-5');
        assert.equal(linkEls[2].getAttribute('href'), '42-glados.txt-10-5');
      });
    });

    test('_handlePatchChange calls navigateToDiff correctly', () => {
      const navigateStub = sandbox.stub(Gerrit.Nav, 'navigateToDiff');
      element._change = {_number: 321, project: 'foo/bar'};
      element._path = 'path/to/file.txt';

      element._patchRange = {
        basePatchNum: 'PARENT',
        patchNum: '3',
      };

      const detail = {
        basePatchNum: 'PARENT',
        patchNum: '1',
      };

      element.$.rangeSelect.dispatchEvent(
          new CustomEvent('patch-range-change', {detail, bubbles: false}));

      assert(navigateStub.lastCall.calledWithExactly(element._change,
          element._path, '1', 'PARENT'));
    });

    test('download link', () => {
      element._changeNum = '42';
      element._patchRange = {
        basePatchNum: PARENT,
        patchNum: '10',
      };
      element._fileList = ['chell.go', 'glados.txt', 'wheatley.md'];
      element._path = 'glados.txt';
      flushAsynchronousOperations();
      const link = element.$$('.downloadLink');
      assert.equal(link.getAttribute('href'),
          '/changes/42/revisions/10/patch?zip&path=glados.txt');
      assert.isTrue(link.hasAttribute('download'));
    });

    test('_prefs.manual_review is respected', () => {
      const saveReviewedStub = sandbox.stub(element, '_saveReviewedState',
          () => Promise.resolve());
      const getReviewedStub = sandbox.stub(element, '_getReviewedStatus',
          () => Promise.resolve());

      sandbox.stub(element.$.diffHost, 'reload');
      element._loggedIn = true;
      element.params = {
        view: Gerrit.Nav.View.DIFF,
        changeNum: '42',
        patchNum: '2',
        basePatchNum: '1',
        path: '/COMMIT_MSG',
      };
      element._prefs = {manual_review: true};
      flushAsynchronousOperations();

      assert.isFalse(saveReviewedStub.called);
      assert.isTrue(getReviewedStub.called);

      element._prefs = {};
      flushAsynchronousOperations();

      assert.isTrue(saveReviewedStub.called);
      assert.isTrue(getReviewedStub.calledOnce);
    });

    test('file review status', () => {
      const saveReviewedStub = sandbox.stub(element, '_saveReviewedState',
          () => Promise.resolve());
      sandbox.stub(element.$.diffHost, 'reload');

      element._loggedIn = true;
      element.params = {
        view: Gerrit.Nav.View.DIFF,
        changeNum: '42',
        patchNum: '2',
        basePatchNum: '1',
        path: '/COMMIT_MSG',
      };
      element._prefs = {};
      flushAsynchronousOperations();

      const commitMsg = Polymer.dom(element.root).querySelector(
          'input[type="checkbox"]');

      assert.isTrue(commitMsg.checked);
      MockInteractions.tap(commitMsg);
      assert.isFalse(commitMsg.checked);
      assert.isTrue(saveReviewedStub.lastCall.calledWithExactly(false));

      MockInteractions.tap(commitMsg);
      assert.isTrue(commitMsg.checked);
      assert.isTrue(saveReviewedStub.lastCall.calledWithExactly(true));
      const callCount = saveReviewedStub.callCount;

      element.set('params.view', Gerrit.Nav.View.CHANGE);
      flushAsynchronousOperations();

      // saveReviewedState observer observes params, but should not fire when
      // view !== Gerrit.Nav.View.DIFF.
      assert.equal(saveReviewedStub.callCount, callCount);
    });

    test('file review status with edit loaded', () => {
      const saveReviewedStub = sandbox.stub(element, '_saveReviewedState');

      element._patchRange = {patchNum: element.EDIT_NAME};
      flushAsynchronousOperations();

      assert.isTrue(element._editMode);
      element._setReviewed();
      assert.isFalse(saveReviewedStub.called);
    });

    test('hash is determined from params', done => {
      sandbox.stub(element.$.diffHost, 'reload');
      sandbox.stub(element, '_initCursor');

      element._loggedIn = true;
      element.params = {
        view: Gerrit.Nav.View.DIFF,
        changeNum: '42',
        patchNum: '2',
        basePatchNum: '1',
        path: '/COMMIT_MSG',
        hash: 10,
      };

      flush(() => {
        assert.isTrue(element._initCursor.calledOnce);
        done();
      });
    });

    test('diff mode selector correctly toggles the diff', () => {
      const select = element.$.modeSelect;
      const diffDisplay = element.$.diffHost;
      element._userPrefs = {default_diff_view: 'SIDE_BY_SIDE'};

      // The mode selected in the view state reflects the selected option.
      assert.equal(element._getDiffViewMode(), select.mode);

      // The mode selected in the view state reflects the view rednered in the
      // diff.
      assert.equal(select.mode, diffDisplay.viewMode);

      // We will simulate a user change of the selected mode.
      const newMode = 'UNIFIED_DIFF';

      // Set the mode, and simulate the change event.
      element.set('changeViewState.diffMode', newMode);

      // Make sure the handler was called and the state is still coherent.
      assert.equal(element._getDiffViewMode(), newMode);
      assert.equal(element._getDiffViewMode(), select.mode);
      assert.equal(element._getDiffViewMode(), diffDisplay.viewMode);
    });

    test('diff mode selector initializes from preferences', () => {
      let resolvePrefs;
      const prefsPromise = new Promise(resolve => {
        resolvePrefs = resolve;
      });
      sandbox.stub(element.$.restAPI, 'getPreferences', () => prefsPromise);

      // Attach a new gr-diff-view so we can intercept the preferences fetch.
      const view = document.createElement('gr-diff-view');
      fixture('blank').appendChild(view);
      flushAsynchronousOperations();

      // At this point the diff mode doesn't yet have the user's preference.
      assert.equal(view._getDiffViewMode(), 'SIDE_BY_SIDE');

      // Receive the overriding preference.
      resolvePrefs({default_diff_view: 'UNIFIED'});
      flushAsynchronousOperations();
      assert.equal(element._getDiffViewMode(), 'SIDE_BY_SIDE');
    });

    suite('_commitRange', () => {
      setup(() => {
        sandbox.stub(element.$.diffHost, 'reload');
        sandbox.stub(element, '_initCursor');
        sandbox.stub(element, '_getChangeDetail').returns(Promise.resolve({
          _number: 42,
          revisions: {
            'commit-sha-1': {
              _number: 1,
              commit: {
                parents: [{commit: 'sha-1-parent'}],
              },
            },
            'commit-sha-2': {_number: 2},
            'commit-sha-3': {_number: 3},
            'commit-sha-4': {_number: 4},
            'commit-sha-5': {
              _number: 5,
              commit: {
                parents: [{commit: 'sha-5-parent'}],
              },
            },
          },
        }));
      });

      test('uses the patchNum and basePatchNum ', done => {
        element.params = {
          view: Gerrit.Nav.View.DIFF,
          changeNum: '42',
          patchNum: '4',
          basePatchNum: '2',
          path: '/COMMIT_MSG',
        };
        flush(() => {
          assert.deepEqual(element._commitRange, {
            baseCommit: 'commit-sha-2',
            commit: 'commit-sha-4',
          });
          done();
        });
      });

      test('uses the parent when there is no base patch num ', done => {
        element.params = {
          view: Gerrit.Nav.View.DIFF,
          changeNum: '42',
          patchNum: '5',
          path: '/COMMIT_MSG',
        };
        flush(() => {
          assert.deepEqual(element._commitRange, {
            commit: 'commit-sha-5',
            baseCommit: 'sha-5-parent',
          });
          done();
        });
      });
    });

    test('_initCursor', () => {
      assert.isNotOk(element.$.cursor.initialLineNumber);

      // Does nothing when params specify no cursor address:
      element._initCursor({});
      assert.isNotOk(element.$.cursor.initialLineNumber);

      // Does nothing when params specify side but no number:
      element._initCursor({leftSide: true});
      assert.isNotOk(element.$.cursor.initialLineNumber);

      // Revision hash: specifies lineNum but not side.
      element._initCursor({lineNum: 234});
      assert.equal(element.$.cursor.initialLineNumber, 234);
      assert.equal(element.$.cursor.side, 'right');

      // Base hash: specifies lineNum and side.
      element._initCursor({leftSide: true, lineNum: 345});
      assert.equal(element.$.cursor.initialLineNumber, 345);
      assert.equal(element.$.cursor.side, 'left');

      // Specifies right side:
      element._initCursor({leftSide: false, lineNum: 123});
      assert.equal(element.$.cursor.initialLineNumber, 123);
      assert.equal(element.$.cursor.side, 'right');
    });

    test('_getLineOfInterest', () => {
      assert.isNull(element._getLineOfInterest({}));

      let result = element._getLineOfInterest({lineNum: 12});
      assert.equal(result.number, 12);
      assert.isNotOk(result.leftSide);

      result = element._getLineOfInterest({lineNum: 12, leftSide: true});
      assert.equal(result.number, 12);
      assert.isOk(result.leftSide);
    });

    test('_onLineSelected', () => {
      const getUrlStub = sandbox.stub(Gerrit.Nav, 'getUrlForDiffById');
      const replaceStateStub = sandbox.stub(history, 'replaceState');
      const moveStub = sandbox.stub(element.$.cursor, 'moveToLineNumber');
      sandbox.stub(element.$.cursor, 'getAddress')
          .returns({number: 123, isLeftSide: false});

      element._changeNum = 321;
      element._change = {_number: 321, project: 'foo/bar'};
      element._patchRange = {
        basePatchNum: '3',
        patchNum: '5',
      };
      const e = {};
      const detail = {number: 123, side: 'right'};

      element._onLineSelected(e, detail);

      assert.isTrue(moveStub.called);
      assert.equal(moveStub.lastCall.args[0], detail.number);
      assert.equal(moveStub.lastCall.args[1], detail.side);

      assert.isTrue(replaceStateStub.called);
      assert.isTrue(getUrlStub.called);
    });

    test('_onLineSelected w/o line address', () => {
      const getUrlStub = sandbox.stub(Gerrit.Nav, 'getUrlForDiffById');
      sandbox.stub(history, 'replaceState');
      sandbox.stub(element.$.cursor, 'moveToLineNumber');
      sandbox.stub(element.$.cursor, 'getAddress').returns(null);
      element._changeNum = 321;
      element._change = {_number: 321, project: 'foo/bar'};
      element._patchRange = {basePatchNum: '3', patchNum: '5'};
      element._onLineSelected({}, {number: 123, side: 'right'});
      assert.isTrue(getUrlStub.calledOnce);
      assert.isUndefined(getUrlStub.lastCall.args[5]);
      assert.isUndefined(getUrlStub.lastCall.args[6]);
    });

    test('_getDiffViewMode', () => {
      // No user prefs or change view state set.
      assert.equal(element._getDiffViewMode(), 'SIDE_BY_SIDE');

      // User prefs but no change view state set.
      element._userPrefs = {default_diff_view: 'UNIFIED_DIFF'};
      assert.equal(element._getDiffViewMode(), 'UNIFIED_DIFF');

      // User prefs and change view state set.
      element.changeViewState = {diffMode: 'SIDE_BY_SIDE'};
      assert.equal(element._getDiffViewMode(), 'SIDE_BY_SIDE');
    });

    test('_handleMKey', () => {
      sandbox.stub(element, 'shouldSuppressKeyboardShortcut').returns(false);
      const e = {preventDefault: () => {}};
      // Initial state.
      assert.equal(element._getDiffViewMode(), 'SIDE_BY_SIDE');

      element._handleMKey(e);
      assert.equal(element._getDiffViewMode(), 'UNIFIED_DIFF');

      element._handleMKey(e);
      assert.equal(element._getDiffViewMode(), 'SIDE_BY_SIDE');
    });

    suite('_loadComments', () => {
      test('empty', done => {
        element._loadComments().then(() => {
          assert.equal(Object.keys(element._commentMap).length, 0);
          done();
        });
      });

      test('has paths', done => {
        sandbox.stub(element, '_getPaths').returns({
          'path/to/file/one.cpp': [{patch_set: 3, message: 'lorem'}],
          'path-to/file/two.py': [{patch_set: 5, message: 'ipsum'}],
        });
        sandbox.stub(element, '_getCommentsForPath').returns({meta: {}});
        element._changeNum = '42';
        element._patchRange = {
          basePatchNum: '3',
          patchNum: '5',
        };
        element._loadComments().then(() => {
          assert.deepEqual(Object.keys(element._commentMap),
              ['path/to/file/one.cpp', 'path-to/file/two.py']);
          done();
        });
      });
    });

    suite('_computeCommentSkips', () => {
      test('empty file list', () => {
        const commentMap = {
          'path/one.jpg': true,
          'path/three.wav': true,
        };
        const path = 'path/two.m4v';
        const fileList = [];
        const result = element._computeCommentSkips(commentMap, fileList, path);
        assert.isNull(result.previous);
        assert.isNull(result.next);
      });

      test('finds skips', () => {
        const fileList = ['path/one.jpg', 'path/two.m4v', 'path/three.wav'];
        let path = fileList[1];
        const commentMap = {};
        commentMap[fileList[0]] = true;
        commentMap[fileList[1]] = false;
        commentMap[fileList[2]] = true;

        let result = element._computeCommentSkips(commentMap, fileList, path);
        assert.equal(result.previous, fileList[0]);
        assert.equal(result.next, fileList[2]);

        commentMap[fileList[1]] = true;

        result = element._computeCommentSkips(commentMap, fileList, path);
        assert.equal(result.previous, fileList[0]);
        assert.equal(result.next, fileList[2]);

        path = fileList[0];

        result = element._computeCommentSkips(commentMap, fileList, path);
        assert.isNull(result.previous);
        assert.equal(result.next, fileList[1]);

        path = fileList[2];

        result = element._computeCommentSkips(commentMap, fileList, path);
        assert.equal(result.previous, fileList[1]);
        assert.isNull(result.next);
      });

      suite('skip next/previous', () => {
        let navToChangeStub;
        let navToDiffStub;

        setup(() => {
          navToChangeStub = sandbox.stub(element, '_navToChangeView');
          navToDiffStub = sandbox.stub(Gerrit.Nav, 'navigateToDiff');
          element._fileList = [
            'path/one.jpg', 'path/two.m4v', 'path/three.wav',
          ];
          element._patchRange = {patchNum: '2', basePatchNum: '1'};
        });

        suite('_moveToPreviousFileWithComment', () => {
          test('no skips', () => {
            element._moveToPreviousFileWithComment();
            assert.isFalse(navToChangeStub.called);
            assert.isFalse(navToDiffStub.called);
          });

          test('no previous', () => {
            const commentMap = {};
            commentMap[element._fileList[0]] = false;
            commentMap[element._fileList[1]] = false;
            commentMap[element._fileList[2]] = true;
            element._commentMap = commentMap;
            element._path = element._fileList[1];

            element._moveToPreviousFileWithComment();
            assert.isTrue(navToChangeStub.calledOnce);
            assert.isFalse(navToDiffStub.called);
          });

          test('w/ previous', () => {
            const commentMap = {};
            commentMap[element._fileList[0]] = true;
            commentMap[element._fileList[1]] = false;
            commentMap[element._fileList[2]] = true;
            element._commentMap = commentMap;
            element._path = element._fileList[1];

            element._moveToPreviousFileWithComment();
            assert.isFalse(navToChangeStub.called);
            assert.isTrue(navToDiffStub.calledOnce);
          });
        });

        suite('_moveToNextFileWithComment', () => {
          test('no skips', () => {
            element._moveToNextFileWithComment();
            assert.isFalse(navToChangeStub.called);
            assert.isFalse(navToDiffStub.called);
          });

          test('no previous', () => {
            const commentMap = {};
            commentMap[element._fileList[0]] = true;
            commentMap[element._fileList[1]] = false;
            commentMap[element._fileList[2]] = false;
            element._commentMap = commentMap;
            element._path = element._fileList[1];

            element._moveToNextFileWithComment();
            assert.isTrue(navToChangeStub.calledOnce);
            assert.isFalse(navToDiffStub.called);
          });

          test('w/ previous', () => {
            const commentMap = {};
            commentMap[element._fileList[0]] = true;
            commentMap[element._fileList[1]] = false;
            commentMap[element._fileList[2]] = true;
            element._commentMap = commentMap;
            element._path = element._fileList[1];

            element._moveToNextFileWithComment();
            assert.isFalse(navToChangeStub.called);
            assert.isTrue(navToDiffStub.calledOnce);
          });
        });
      });
    });

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

    test('_computeFileNum', () => {
      assert.equal(element._computeFileNum('/foo',
          [{value: '/foo'}, {value: '/bar'}]), 1);
      assert.equal(element._computeFileNum('/bar',
          [{value: '/foo'}, {value: '/bar'}]), 2);
    });

    test('_computeFileNumClass', () => {
      assert.equal(element._computeFileNumClass(0, []), '');
      assert.equal(element._computeFileNumClass(1,
          [{value: '/foo'}, {value: '/bar'}]), 'show');
    });

    test('_getReviewedStatus', () => {
      const promises = [];
      element.$.restAPI.getReviewedFiles.restore();

      sandbox.stub(element.$.restAPI, 'getReviewedFiles')
          .returns(Promise.resolve(['path']));

      promises.push(element._getReviewedStatus(true, null, null, 'path')
          .then(reviewed => assert.isFalse(reviewed)));

      promises.push(element._getReviewedStatus(false, null, null, 'otherPath')
          .then(reviewed => assert.isFalse(reviewed)));

      promises.push(element._getReviewedStatus(false, null, null, 'path')
          .then(reviewed => assert.isTrue(reviewed)));

      return Promise.all(promises);
    });

    suite('editMode behavior', () => {
      setup(() => {
        element._loggedIn = true;
      });

      const isVisible = el => {
        assert.ok(el);
        return getComputedStyle(el).getPropertyValue('display') !== 'none';
      };

      test('reviewed checkbox', () => {
        sandbox.stub(element, '_handlePatchChange');
        element._patchRange = {patchNum: '1'};
        // Reviewed checkbox should be shown.
        assert.isTrue(isVisible(element.$.reviewed));
        element.set('_patchRange.patchNum', element.EDIT_NAME);
        flushAsynchronousOperations();

        assert.isFalse(isVisible(element.$.reviewed));
      });
    });

    test('_paramsChanged sets in projectLookup', () => {
      sandbox.stub(element, '_getLineOfInterest');
      sandbox.stub(element, '_initCursor');
      const setStub = sandbox.stub(element.$.restAPI, 'setInProjectLookup');
      element._paramsChanged({
        view: Gerrit.Nav.View.DIFF,
        changeNum: 101,
        project: 'test-project',
        path: '',
      });
      assert.isTrue(setStub.calledOnce);
      assert.isTrue(setStub.calledWith(101, 'test-project'));
    });
  });
</script>