Add clean-sidebar feature (#2011)

readme.md

@@ -158,6 +158,7 @@ GitHub Enterprise is also supported. More info in the options.
 - [Forks and watchers counters are hidden.](https://user-images.githubusercontent.com/1402241/53681077-f3328b80-3d1e-11e9-9e29-2cb017141769.png)
 - [Diff signs are hidden.](https://user-images.githubusercontent.com/1402241/54807718-149cec80-4cb9-11e9-869c-e265863211e3.png)
 - [Hide milestone sorter UI if you don’t have permission to use it.](https://user-images.githubusercontent.com/7753001/56913933-738a2880-6ae5-11e9-9d13-1973cbbf5df0.png)
+- [Empty sections in the issue/PRs sidebar are hidden.](https://user-images.githubusercontent.com/1402241/57199809-20691780-6fb6-11e9-9672-1ad3f9e1b827.png)
 
 
 ### UI improvements

source/content.ts

@@ -100,6 +100,7 @@ import './features/filter-pr-by-build-status';
 import './features/edit-files-faster';
 import './features/hide-disabled-milestone-sorter';
 import './features/link-to-file-in-file-history';
+import './features/clean-sidebar';
 
 import './features/scrollable-code-and-blockquote.css';
 import './features/center-reactions-popup.css';

source/features/clean-sidebar.css

@@ -0,0 +1,9 @@
+/* Adjust spacing of empty sections */
+.discussion-sidebar-item.rgh-clean-sidebar {
+	margin-bottom: -5px;
+}
+
+/* Remove message under the `Unsubscribe` button */
+.sidebar-notifications .reason {
+	display: none !important;
+}

source/features/clean-sidebar.tsx

@@ -0,0 +1,97 @@
+/*
+Hide all empty sections (or just their "empty" label) in discussion sidebar
+*/
+
+import './clean-sidebar.css';
+import React from 'dom-chef';
+import select from 'select-dom';
+import features from '../libs/features';
+import observeEl from '../libs/simplified-element-observer';
+import {isPR} from '../libs/page-detect';
+
+let canEditSidebar = false;
+
+// Selector points to element containing list of elements or "No labels" text
+function cleanSection(selector: string): boolean {
+	const list = select(selector)!;
+	if (list.children.length === 0) {
+		const section = list.closest('.discussion-sidebar-item')!;
+		if (canEditSidebar) {
+			list.remove();
+			section.classList.add('rgh-clean-sidebar');
+		} else {
+			section.remove();
+		}
+
+		return true;
+	}
+
+	return false;
+}
+
+function clean(): void {
+	if (select.exists('.rgh-clean-sidebar')) {
+		return;
+	}
+
+	select('#partial-discussion-sidebar')!.classList.add('rgh-clean-sidebar');
+
+	// Assignees
+	const assignees = select('.js-issue-assignees')!;
+	if (assignees.children.length === 0) {
+		assignees.closest('.discussion-sidebar-item')!.remove();
+	} else {
+		const assignYourself = select('.js-issue-assign-self');
+		if (assignYourself) {
+			(assignYourself.previousSibling as ChildNode).remove(); // Drop "No one — "
+			select('[aria-label="Select assignees"] summary')!.append(
+				<span style={{fontWeight: 'normal'}}> – {assignYourself}</span>
+			);
+			assignees.closest('.discussion-sidebar-item')!.classList.add('rgh-clean-sidebar');
+		}
+	}
+
+	// Reviewers
+	if (isPR()) {
+		cleanSection('[aria-label="Select reviewers"] > .css-truncate');
+	}
+
+	// Labels
+	if (!cleanSection('.js-issue-labels') && !canEditSidebar) {
+		select('.sidebar-labels div.discussion-sidebar-heading')!.remove();
+	}
+
+	// Projects
+	cleanSection('.sidebar-projects');
+
+	// Milestones
+	const milestones = select('.sidebar-milestone')!;
+	const milestonesInfo = milestones.lastChild!.lastChild!;
+	if (milestonesInfo.textContent!.trim() === 'No milestone') {
+		if (canEditSidebar) {
+			milestonesInfo.remove();
+			milestones.classList.add('rgh-clean-sidebar');
+		} else {
+			milestones.remove();
+		}
+	}
+
+	// Notifications
+	select('.sidebar-notifications .discussion-sidebar-heading')!.remove();
+}
+
+function init(): void {
+	canEditSidebar = select.exists('.sidebar-labels .octicon-gear');
+	clean();
+	observeEl('.discussion-sidebar', clean);
+}
+
+features.add({
+	id: 'link-to-file-in-file-history',
+	include: [
+		features.isIssue,
+		features.isPRConversation
+	],
+	load: features.onAjaxedPages,
+	init
+});

source/features/hide-tips.css

@@ -28,11 +28,6 @@ a.tabnav-extra[href$='mastering-markdown/'] {
 	display: none !important;
 }
 
-/* Remove message under the `Unsubscribe` button */
-.sidebar-notifications .reason {
-	display: none !important;
-}
-
 /* Remove Marketplace marketing box on PRs */
 .js-marketplace-callout-container {
 	display: none !important;