blob: 4f076641544d96976e55b6f4509057f721491338 [file] [log] [blame]
/**
* @license
* Copyright (C) 2016 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.
*/
(function() {
'use strict';
const ERR_COMMENT_ON_EDIT = 'You cannot comment on an edit.';
const ERR_COMMENT_ON_EDIT_BASE = 'You cannot comment on the base patch set ' +
'of an edit.';
const ERR_INVALID_LINE = 'Invalid line number: ';
const NO_NEWLINE_BASE = 'No newline at end of base file.';
const NO_NEWLINE_REVISION = 'No newline at end of revision file.';
const DiffViewMode = {
SIDE_BY_SIDE: 'SIDE_BY_SIDE',
UNIFIED: 'UNIFIED_DIFF',
};
const DiffSide = {
LEFT: 'left',
RIGHT: 'right',
};
const LARGE_DIFF_THRESHOLD_LINES = 10000;
const FULL_CONTEXT = -1;
const LIMITED_CONTEXT = 10;
/**
* Compare two ranges. Either argument may be falsy, but will only return
* true if both are falsy or if neither are falsy and have the same position
* values.
*
* @param {Gerrit.Range=} a range 1
* @param {Gerrit.Range=} b range 2
* @return {boolean}
*/
Gerrit.rangesEqual = function(a, b) {
if (!a && !b) { return true; }
if (!a || !b) { return false; }
return a.start_line === b.start_line &&
a.start_character === b.start_character &&
a.end_line === b.end_line &&
a.end_character === b.end_character;
};
function isThreadEl(node) {
return node.nodeType === Node.ELEMENT_NODE &&
node.classList.contains('comment-thread');
}
/**
* Turn a slot element into the corresponding content element.
* Slots are only fully supported in Polymer 2 - in Polymer 1, they are
* replaced with content elements during template parsing. This conversion is
* not applied for imperatively created slot elements, so this method
* implements the same behavior as the template parsing for imperative slots.
*/
Gerrit.slotToContent = function(slot) {
if (Polymer.Element) {
return slot;
}
const content = document.createElement('content');
content.name = slot.name;
content.setAttribute('select', `[slot='${slot.name}']`);
return content;
};
const COMMIT_MSG_PATH = '/COMMIT_MSG';
/**
* 72 is the inofficial length standard for git commit messages.
* Derived from the fact that git log/show appends 4 ws in the beginning of
* each line when displaying commit messages. To center the commit message
* in an 80 char terminal a 4 ws border is added to the rightmost side:
* 4 + 72 + 4
*/
const COMMIT_MSG_LINE_LENGTH = 72;
const RENDER_DIFF_TABLE_DEBOUNCE_NAME = 'renderDiffTable';
Polymer({
is: 'gr-diff',
/**
* Fired when the user selects a line.
*
* @event line-selected
*/
/**
* Fired if being logged in is required.
*
* @event show-auth-required
*/
/**
* Fired when a comment is created
*
* @event create-comment
*/
/**
* Fired when rendering, including syntax highlighting, is done. Also fired
* when no rendering can be done because required preferences are not set.
*
* @event render
*/
properties: {
changeNum: String,
noAutoRender: {
type: Boolean,
value: false,
},
/** @type {?} */
patchRange: Object,
path: {
type: String,
observer: '_pathObserver',
},
prefs: {
type: Object,
observer: '_prefsObserver',
},
projectName: String,
displayLine: {
type: Boolean,
value: false,
},
isImageDiff: {
type: Boolean,
},
commitRange: Object,
hidden: {
type: Boolean,
reflectToAttribute: true,
},
noRenderOnPrefsChange: Boolean,
/** @type {!Array<!Gerrit.HoveredRange>} */
_commentRanges: {
type: Array,
value: () => [],
},
/** @type {!Array<!Gerrit.CoverageRange>} */
coverageRanges: {
type: Array,
value: () => [],
},
lineWrapping: {
type: Boolean,
value: false,
observer: '_lineWrappingObserver',
},
viewMode: {
type: String,
value: DiffViewMode.SIDE_BY_SIDE,
observer: '_viewModeObserver',
},
/** @type {?Gerrit.LineOfInterest} */
lineOfInterest: Object,
loading: {
type: Boolean,
value: false,
observer: '_loadingChanged',
},
loggedIn: {
type: Boolean,
value: false,
},
diff: {
type: Object,
observer: '_diffChanged',
},
_diffHeaderItems: {
type: Array,
value: [],
computed: '_computeDiffHeaderItems(diff.*)',
},
_diffTableClass: {
type: String,
value: '',
},
/** @type {?Object} */
baseImage: Object,
/** @type {?Object} */
revisionImage: Object,
/**
* Whether the safety check for large diffs when whole-file is set has
* been bypassed. If the value is null, then the safety has not been
* bypassed. If the value is a number, then that number represents the
* context preference to use when rendering the bypassed diff.
*
* @type {number|null}
*/
_safetyBypass: {
type: Number,
value: null,
},
_showWarning: Boolean,
/** @type {?string} */
errorMessage: {
type: String,
value: null,
},
/** @type {?Object} */
blame: {
type: Object,
value: null,
observer: '_blameChanged',
},
parentIndex: Number,
_newlineWarning: {
type: String,
computed: '_computeNewlineWarning(diff)',
},
_diffLength: Number,
/**
* Observes comment nodes added or removed after the initial render.
* Can be used to unregister when the entire diff is (re-)rendered or upon
* detachment.
*
* @type {?PolymerDomApi.ObserveHandle}
*/
_incrementalNodeObserver: Object,
/**
* Observes comment nodes added or removed at any point.
* Can be used to unregister upon detachment.
*
* @type {?PolymerDomApi.ObserveHandle}
*/
_nodeObserver: Object,
/** Set by Polymer. */
isAttached: Boolean,
layers: Array,
},
behaviors: [
Gerrit.FireBehavior,
Gerrit.PatchSetBehavior,
],
listeners: {
'create-range-comment': '_handleCreateRangeComment',
'render-content': '_handleRenderContent',
},
observers: [
'_enableSelectionObserver(loggedIn, isAttached)',
],
attached() {
this._observeNodes();
},
detached() {
this._unobserveIncrementalNodes();
this._unobserveNodes();
},
showNoChangeMessage(loading, prefs, diffLength) {
return !loading &&
prefs && prefs.ignore_whitespace !== 'IGNORE_NONE'
&& diffLength === 0;
},
_enableSelectionObserver(loggedIn, isAttached) {
// Polymer 2: check for undefined
if ([loggedIn, isAttached].some(arg => arg === undefined)) {
return;
}
if (loggedIn && isAttached) {
this.listen(document, 'selectionchange', '_handleSelectionChange');
this.listen(document, 'mouseup', '_handleMouseUp');
} else {
this.unlisten(document, 'selectionchange', '_handleSelectionChange');
this.unlisten(document, 'mouseup', '_handleMouseUp');
}
},
_handleSelectionChange() {
// Because of shadow DOM selections, we handle the selectionchange here,
// and pass the shadow DOM selection into gr-diff-highlight, where the
// corresponding range is determined and normalized.
const selection = this._getShadowOrDocumentSelection();
this.$.highlights.handleSelectionChange(selection, false);
},
_handleMouseUp(e) {
// To handle double-click outside of text creating comments, we check on
// mouse-up if there's a selection that just covers a line change. We
// can't do that on selection change since the user may still be dragging.
const selection = this._getShadowOrDocumentSelection();
this.$.highlights.handleSelectionChange(selection, true);
},
/** Gets the current selection, preferring the shadow DOM selection. */
_getShadowOrDocumentSelection() {
// When using native shadow DOM, the selection returned by
// document.getSelection() cannot reference the actual DOM elements making
// up the diff, because they are in the shadow DOM of the gr-diff element.
// This takes the shadow DOM selection if one exists.
return this.root.getSelection ?
this.root.getSelection() :
document.getSelection();
},
_observeNodes() {
this._nodeObserver = Polymer.dom(this).observeNodes(info => {
const addedThreadEls = info.addedNodes.filter(isThreadEl);
const removedThreadEls = info.removedNodes.filter(isThreadEl);
this._updateRanges(addedThreadEls, removedThreadEls);
this._redispatchHoverEvents(addedThreadEls);
});
},
_updateRanges(addedThreadEls, removedThreadEls) {
function commentRangeFromThreadEl(threadEl) {
const side = threadEl.getAttribute('comment-side');
const range = JSON.parse(threadEl.getAttribute('range'));
return {side, range, hovering: false};
}
const addedCommentRanges = addedThreadEls
.map(commentRangeFromThreadEl)
.filter(({range}) => range);
const removedCommentRanges = removedThreadEls
.map(commentRangeFromThreadEl)
.filter(({range}) => range);
for (const removedCommentRange of removedCommentRanges) {
const i = this._commentRanges.findIndex(commentRange => {
return commentRange.side === removedCommentRange.side &&
Gerrit.rangesEqual(commentRange.range, removedCommentRange.range);
});
this.splice('_commentRanges', i, 1);
}
if (addedCommentRanges && addedCommentRanges.length) {
this.push('_commentRanges', ...addedCommentRanges);
}
},
/**
* The key locations based on the comments and line of interests,
* where lines should not be collapsed.
*
* @return {{left: Object<(string|number), boolean>,
* right: Object<(string|number), boolean>}}
*/
_computeKeyLocations() {
const keyLocations = {left: {}, right: {}};
if (this.lineOfInterest) {
const side = this.lineOfInterest.leftSide ? 'left' : 'right';
keyLocations[side][this.lineOfInterest.number] = true;
}
const threadEls = Polymer.dom(this).getEffectiveChildNodes()
.filter(isThreadEl);
for (const threadEl of threadEls) {
const commentSide = threadEl.getAttribute('comment-side');
const lineNum = Number(threadEl.getAttribute('line-num')) ||
GrDiffLine.FILE;
const commentRange = threadEl.range || {};
keyLocations[commentSide][lineNum] = true;
// Add start_line as well if exists,
// the being and end of the range should not be collapsed.
if (commentRange.start_line) {
keyLocations[commentSide][commentRange.start_line] = true;
}
}
return keyLocations;
},
// Dispatch events that are handled by the gr-diff-highlight.
_redispatchHoverEvents(addedThreadEls) {
for (const threadEl of addedThreadEls) {
threadEl.addEventListener('mouseenter', () => {
threadEl.dispatchEvent(new CustomEvent(
'comment-thread-mouseenter', {bubbles: true, composed: true}));
});
threadEl.addEventListener('mouseleave', () => {
threadEl.dispatchEvent(new CustomEvent(
'comment-thread-mouseleave', {bubbles: true, composed: true}));
});
}
},
/** Cancel any remaining diff builder rendering work. */
cancel() {
this.$.diffBuilder.cancel();
this.cancelDebouncer(RENDER_DIFF_TABLE_DEBOUNCE_NAME);
},
/** @return {!Array<!HTMLElement>} */
getCursorStops() {
if (this.hidden && this.noAutoRender) {
return [];
}
return Array.from(
Polymer.dom(this.root).querySelectorAll('.diff-row'));
},
/** @return {boolean} */
isRangeSelected() {
return this.$.highlights.isRangeSelected();
},
toggleLeftDiff() {
this.toggleClass('no-left');
},
_blameChanged(newValue) {
this.$.diffBuilder.setBlame(newValue);
if (newValue) {
this.classList.add('showBlame');
} else {
this.classList.remove('showBlame');
}
},
/** @return {string} */
_computeContainerClass(loggedIn, viewMode, displayLine) {
const classes = ['diffContainer'];
switch (viewMode) {
case DiffViewMode.UNIFIED:
classes.push('unified');
break;
case DiffViewMode.SIDE_BY_SIDE:
classes.push('sideBySide');
break;
default:
throw Error('Invalid view mode: ', viewMode);
}
if (Gerrit.hiddenscroll) {
classes.push('hiddenscroll');
}
if (loggedIn) {
classes.push('canComment');
}
if (displayLine) {
classes.push('displayLine');
}
return classes.join(' ');
},
_handleTap(e) {
const el = Polymer.dom(e).localTarget;
if (el.classList.contains('showContext')) {
this.$.diffBuilder.showContext(e.detail.groups, e.detail.section);
} else if (el.classList.contains('lineNum')) {
this.addDraftAtLine(el);
} else if (el.tagName === 'HL' ||
el.classList.contains('content') ||
el.classList.contains('contentText')) {
const target = this.$.diffBuilder.getLineElByChild(el);
if (target) { this._selectLine(target); }
}
},
_selectLine(el) {
this.fire('line-selected', {
side: el.classList.contains('left') ? DiffSide.LEFT : DiffSide.RIGHT,
number: el.getAttribute('data-value'),
path: this.path,
});
},
addDraftAtLine(el) {
this._selectLine(el);
if (!this._isValidElForComment(el)) { return; }
const value = el.getAttribute('data-value');
let lineNum;
if (value !== GrDiffLine.FILE) {
lineNum = parseInt(value, 10);
if (isNaN(lineNum)) {
this.fire('show-alert', {message: ERR_INVALID_LINE + value});
return;
}
}
this._createComment(el, lineNum);
},
_handleCreateRangeComment(e) {
const range = e.detail.range;
const side = e.detail.side;
const lineNum = range.end_line;
const lineEl = this.$.diffBuilder.getLineElByNumber(lineNum, side);
if (this._isValidElForComment(lineEl)) {
this._createComment(lineEl, lineNum, side, range);
}
},
/** @return {boolean} */
_isValidElForComment(el) {
if (!this.loggedIn) {
this.fire('show-auth-required');
return false;
}
const patchNum = el.classList.contains(DiffSide.LEFT) ?
this.patchRange.basePatchNum :
this.patchRange.patchNum;
const isEdit = this.patchNumEquals(patchNum, this.EDIT_NAME);
const isEditBase = this.patchNumEquals(patchNum, this.PARENT_NAME) &&
this.patchNumEquals(this.patchRange.patchNum, this.EDIT_NAME);
if (isEdit) {
this.fire('show-alert', {message: ERR_COMMENT_ON_EDIT});
return false;
} else if (isEditBase) {
this.fire('show-alert', {message: ERR_COMMENT_ON_EDIT_BASE});
return false;
}
return true;
},
/**
* @param {!Object} lineEl
* @param {number=} lineNum
* @param {string=} side
* @param {!Object=} range
*/
_createComment(lineEl, lineNum=undefined, side=undefined, range=undefined) {
const contentText = this.$.diffBuilder.getContentByLineEl(lineEl);
const contentEl = contentText.parentElement;
side = side ||
this._getCommentSideByLineAndContent(lineEl, contentEl);
const patchForNewThreads = this._getPatchNumByLineAndContent(
lineEl, contentEl);
const isOnParent =
this._getIsParentCommentByLineAndContent(lineEl, contentEl);
this.dispatchEvent(new CustomEvent('create-comment', {
bubbles: true,
composed: true,
detail: {
lineNum,
side,
patchNum: patchForNewThreads,
isOnParent,
range,
},
}));
},
_getThreadGroupForLine(contentEl) {
return contentEl.querySelector('.thread-group');
},
/**
* Gets or creates a comment thread group for a specific line and side on a
* diff.
*
* @param {!Object} contentEl
* @param {!Gerrit.DiffSide} commentSide
* @return {!Node}
*/
_getOrCreateThreadGroup(contentEl, commentSide) {
// Check if thread group exists.
let threadGroupEl = this._getThreadGroupForLine(contentEl);
if (!threadGroupEl) {
threadGroupEl = document.createElement('div');
threadGroupEl.className = 'thread-group';
threadGroupEl.setAttribute('data-side', commentSide);
contentEl.appendChild(threadGroupEl);
}
return threadGroupEl;
},
/**
* The value to be used for the patch number of new comments created at the
* given line and content elements.
*
* In two cases of creating a comment on the left side, the patch number to
* be used should actually be right side of the patch range:
* - When the patch range is against the parent comment of a normal change.
* Such comments declare themmselves to be on the left using side=PARENT.
* - If the patch range is against the indexed parent of a merge change.
* Such comments declare themselves to be on the given parent by
* specifying the parent index via parent=i.
*
* @return {number}
*/
_getPatchNumByLineAndContent(lineEl, contentEl) {
let patchNum = this.patchRange.patchNum;
if ((lineEl.classList.contains(DiffSide.LEFT) ||
contentEl.classList.contains('remove')) &&
this.patchRange.basePatchNum !== 'PARENT' &&
!this.isMergeParent(this.patchRange.basePatchNum)) {
patchNum = this.patchRange.basePatchNum;
}
return patchNum;
},
/** @return {boolean} */
_getIsParentCommentByLineAndContent(lineEl, contentEl) {
if ((lineEl.classList.contains(DiffSide.LEFT) ||
contentEl.classList.contains('remove')) &&
(this.patchRange.basePatchNum === 'PARENT' ||
this.isMergeParent(this.patchRange.basePatchNum))) {
return true;
}
return false;
},
/** @return {string} */
_getCommentSideByLineAndContent(lineEl, contentEl) {
let side = 'right';
if (lineEl.classList.contains(DiffSide.LEFT) ||
contentEl.classList.contains('remove')) {
side = 'left';
}
return side;
},
_prefsObserver(newPrefs, oldPrefs) {
if (!this._prefsEqual(newPrefs, oldPrefs)) {
this._prefsChanged(newPrefs);
}
},
_prefsEqual(prefs1, prefs2) {
if (prefs1 === prefs2) {
return true;
}
if (!prefs1 || !prefs2) {
return false;
}
// Scan the preference objects one level deep to see if they differ.
const keys1 = Object.keys(prefs1);
const keys2 = Object.keys(prefs2);
return keys1.length === keys2.length &&
keys1.every(key => prefs1[key] === prefs2[key]) &&
keys2.every(key => prefs1[key] === prefs2[key]);
},
_pathObserver() {
// Call _prefsChanged(), because line-limit style value depends on path.
this._prefsChanged(this.prefs);
},
_viewModeObserver() {
this._prefsChanged(this.prefs);
},
/** @param {boolean} newValue */
_loadingChanged(newValue) {
if (newValue) {
this.cancel();
this._blame = null;
this._safetyBypass = null;
this._showWarning = false;
this.clearDiffContent();
}
},
_lineWrappingObserver() {
this._prefsChanged(this.prefs);
},
_prefsChanged(prefs) {
if (!prefs) { return; }
this._blame = null;
const lineLength = this.path === COMMIT_MSG_PATH ?
COMMIT_MSG_LINE_LENGTH : prefs.line_length;
const stylesToUpdate = {};
if (prefs.line_wrapping) {
this._diffTableClass = 'full-width';
if (this.viewMode === 'SIDE_BY_SIDE') {
stylesToUpdate['--content-width'] = 'none';
stylesToUpdate['--line-limit'] = lineLength + 'ch';
}
} else {
this._diffTableClass = '';
stylesToUpdate['--content-width'] = lineLength + 'ch';
}
if (prefs.font_size) {
stylesToUpdate['--font-size'] = prefs.font_size + 'px';
}
this.updateStyles(stylesToUpdate);
if (this.diff && !this.noRenderOnPrefsChange) {
this._debounceRenderDiffTable();
}
},
_diffChanged(newValue) {
if (newValue) {
this._diffLength = this.getDiffLength(newValue);
this._debounceRenderDiffTable();
}
},
/**
* When called multiple times from the same microtask, will call
* _renderDiffTable only once, in the next microtask, unless it is cancelled
* before that microtask runs.
*
* This should be used instead of calling _renderDiffTable directly to
* render the diff in response to an input change, because there may be
* multiple inputs changing in the same microtask, but we only want to
* render once.
*/
_debounceRenderDiffTable() {
this.debounce(
RENDER_DIFF_TABLE_DEBOUNCE_NAME, () => this._renderDiffTable());
},
_renderDiffTable() {
this._unobserveIncrementalNodes();
if (!this.prefs) {
this.dispatchEvent(
new CustomEvent('render', {bubbles: true, composed: true}));
return;
}
if (this.prefs.context === -1 &&
this._diffLength >= LARGE_DIFF_THRESHOLD_LINES &&
this._safetyBypass === null) {
this._showWarning = true;
this.dispatchEvent(
new CustomEvent('render', {bubbles: true, composed: true}));
return;
}
this._showWarning = false;
const keyLocations = this._computeKeyLocations();
this.$.diffBuilder.render(keyLocations, this._getBypassPrefs())
.then(() => {
this.dispatchEvent(
new CustomEvent('render', {
bubbles: true,
composed: true,
detail: {contentRendered: true},
}));
});
},
_handleRenderContent() {
this._incrementalNodeObserver = Polymer.dom(this).observeNodes(info => {
const addedThreadEls = info.addedNodes.filter(isThreadEl);
// Removed nodes do not need to be handled because all this code does is
// adding a slot for the added thread elements, and the extra slots do
// not hurt. It's probably a bigger performance cost to remove them than
// to keep them around. Medium term we can even consider to add one slot
// for each line from the start.
let lastEl;
for (const threadEl of addedThreadEls) {
const lineNumString = threadEl.getAttribute('line-num') || 'FILE';
const commentSide = threadEl.getAttribute('comment-side');
const lineEl = this.$.diffBuilder.getLineElByNumber(
lineNumString, commentSide);
const contentText = this.$.diffBuilder.getContentByLineEl(lineEl);
const contentEl = contentText.parentElement;
const threadGroupEl = this._getOrCreateThreadGroup(
contentEl, commentSide);
// Create a slot for the thread and attach it to the thread group.
// The Polyfill has some bugs and this only works if the slot is
// attached to the group after the group is attached to the DOM.
// The thread group may already have a slot with the right name, but
// that is okay because the first matching slot is used and the rest
// are ignored.
const slot = document.createElement('slot');
slot.name = threadEl.getAttribute('slot');
Polymer.dom(threadGroupEl).appendChild(Gerrit.slotToContent(slot));
lastEl = threadEl;
}
// Safari is not binding newly created comment-thread
// with the slot somehow, replace itself will rebind it
// @see Issue 11182
if (lastEl && lastEl.replaceWith) {
lastEl.replaceWith(lastEl);
}
});
},
_unobserveIncrementalNodes() {
if (this._incrementalNodeObserver) {
Polymer.dom(this).unobserveNodes(this._incrementalNodeObserver);
}
},
_unobserveNodes() {
if (this._nodeObserver) {
Polymer.dom(this).unobserveNodes(this._nodeObserver);
}
},
/**
* Get the preferences object including the safety bypass context (if any).
*/
_getBypassPrefs() {
if (this._safetyBypass !== null) {
return Object.assign({}, this.prefs, {context: this._safetyBypass});
}
return this.prefs;
},
clearDiffContent() {
this._unobserveIncrementalNodes();
this.$.diffTable.innerHTML = null;
},
/** @return {!Array} */
_computeDiffHeaderItems(diffInfoRecord) {
const diffInfo = diffInfoRecord.base;
if (!diffInfo || !diffInfo.diff_header) { return []; }
return diffInfo.diff_header.filter(item => {
return !(item.startsWith('diff --git ') ||
item.startsWith('index ') ||
item.startsWith('+++ ') ||
item.startsWith('--- ') ||
item === 'Binary files differ');
});
},
/** @return {boolean} */
_computeDiffHeaderHidden(items) {
return items.length === 0;
},
_handleFullBypass() {
this._safetyBypass = FULL_CONTEXT;
this._debounceRenderDiffTable();
},
_handleLimitedBypass() {
this._safetyBypass = LIMITED_CONTEXT;
this._debounceRenderDiffTable();
},
/** @return {string} */
_computeWarningClass(showWarning) {
return showWarning ? 'warn' : '';
},
/**
* @param {string} errorMessage
* @return {string}
*/
_computeErrorClass(errorMessage) {
return errorMessage ? 'showError' : '';
},
expandAllContext() {
this._handleFullBypass();
},
/**
* Find the last chunk for the given side.
*
* @param {!Object} diff
* @param {boolean} leftSide true if checking the base of the diff,
* false if testing the revision.
* @return {Object|null} returns the chunk object or null if there was
* no chunk for that side.
*/
_lastChunkForSide(diff, leftSide) {
if (!diff.content.length) { return null; }
let chunkIndex = diff.content.length;
let chunk;
// Walk backwards until we find a chunk for the given side.
do {
chunkIndex--;
chunk = diff.content[chunkIndex];
} while (
// We haven't reached the beginning.
chunkIndex >= 0 &&
// The chunk doesn't have both sides.
!chunk.ab &&
// The chunk doesn't have the given side.
((leftSide && (!chunk.a || !chunk.a.length)) ||
(!leftSide && (!chunk.b || !chunk.b.length))));
// If we reached the beginning of the diff and failed to find a chunk
// with the given side, return null.
if (chunkIndex === -1) { return null; }
return chunk;
},
/**
* Check whether the specified side of the diff has a trailing newline.
*
* @param {!Object} diff
* @param {boolean} leftSide true if checking the base of the diff,
* false if testing the revision.
* @return {boolean|null} Return true if the side has a trailing newline.
* Return false if it doesn't. Return null if not applicable (for
* example, if the diff has no content on the specified side).
*/
_hasTrailingNewlines(diff, leftSide) {
const chunk = this._lastChunkForSide(diff, leftSide);
if (!chunk) { return null; }
let lines;
if (chunk.ab) {
lines = chunk.ab;
} else {
lines = leftSide ? chunk.a : chunk.b;
}
return lines[lines.length - 1] === '';
},
/**
* @param {!Object} diff
* @return {string|null}
*/
_computeNewlineWarning(diff) {
const hasLeft = this._hasTrailingNewlines(diff, true);
const hasRight = this._hasTrailingNewlines(diff, false);
const messages = [];
if (hasLeft === false) {
messages.push(NO_NEWLINE_BASE);
}
if (hasRight === false) {
messages.push(NO_NEWLINE_REVISION);
}
if (!messages.length) { return null; }
return messages.join(' — ');
},
/**
* @param {string} warning
* @param {boolean} loading
* @return {string}
*/
_computeNewlineWarningClass(warning, loading) {
if (loading || !warning) { return 'newlineWarning hidden'; }
return 'newlineWarning';
},
/**
* Get the approximate length of the diff as the sum of the maximum
* length of the chunks.
*
* @param {Object} diff object
* @return {number}
*/
getDiffLength(diff) {
if (!diff) return 0;
return diff.content.reduce((sum, sec) => {
if (sec.hasOwnProperty('ab')) {
return sum + sec.ab.length;
} else {
return sum + Math.max(
sec.hasOwnProperty('a') ? sec.a.length : 0,
sec.hasOwnProperty('b') ? sec.b.length : 0);
}
}, 0);
},
});
})();