refined-github · fregante · Jul 27, 2020 · Jul 25, 2020 · Jul 25, 2020 · Jul 25, 2020
diff --git a/readme.md b/readme.md
@@ -228,7 +228,7 @@ Thanks for contributing! 🦋🙌
 - [](# "linkify-commit-sha") [Adds link to non-PR commit when visiting a PR commit.](https://user-images.githubusercontent.com/101152/42968387-606b23f2-8ba3-11e8-8a4b-667bddc8d33c.png)
 - [](# "pr-filters") [Adds Checks and Draft PR dropdown filters in PR lists.](https://user-images.githubusercontent.com/202916/74453250-6d9de200-4e82-11ea-8fd4-7c0de57e001a.png)
 - [](# "pr-approvals-count") [Shows color-coded review counts in PR lists.](https://user-images.githubusercontent.com/1402241/33474535-a814ee78-d6ad-11e7-8f08-a8b72799e376.png)
-- [](# "pr-branches") [Shows head and base branches in PR lists if they’re significant.](https://user-images.githubusercontent.com/1402241/51428391-ae9ed500-1c35-11e9-8e54-6b6a424fede4.png)
+- [](# "highlight-non-default-base-branch") [Shows the base branch in PR lists if it’s not the default branch.](https://user-images.githubusercontent.com/1402241/88480306-39f4d700-cf4d-11ea-9e40-2b36d92d41aa.png)
 - [](# "remove-checks-tab") Hides the `Checks` tab if it’s empty, unless you’re the owner.
 - [](# "hide-inactive-deployments") [Hides inactive deployments.](https://github.com/sindresorhus/refined-github/issues/1144)
 - [](# "previous-next-commit-buttons") [Adds duplicate commit navigation buttons at the bottom of the `Commits` tab page.](https://user-images.githubusercontent.com/24777/41755271-741773de-75a4-11e8-9181-fcc1c73df633.png)

diff --git a/source/features/highlight-non-default-base-branch.tsx b/source/features/highlight-non-default-base-branch.tsx
@@ -0,0 +1,76 @@
+import React from 'dom-chef';
+import select from 'select-dom';
+import * as pageDetect from 'github-url-detection';
+import PullRequestIcon from 'octicon/git-pull-request.svg';
+
+import features from '.';
+import * as api from '../github-helpers/api';
+import getDefaultBranch from '../github-helpers/get-default-branch';
+import {getRepositoryInfo, getRepoGQL} from '../github-helpers';
+
+type BranchInfo = {
+	baseRef: string;
+	baseRefName: string;
+};
+
+function buildQuery(issueIds: string[]): string {
+	return `
+		repository(${getRepoGQL()}) {
+			${issueIds.map(id => `
+				${id}: pullRequest(number: ${id.replace(/\D/g, '')}) {
+					baseRef {id}
+					baseRefName
+				}
+			`).join('\n')}
+		}
+	`;
+}
+
+async function init(): Promise<false | void> {
+	const prLinks = select.all('.js-issue-row .js-navigation-open[data-hovercard-type="pull_request"]');
+	if (prLinks.length === 0) {
+		return false;
+	}
+
+	const currentRepository = getRepositoryInfo();
+	const query = buildQuery(prLinks.map(pr => pr.id));
+	const [data, defaultBranch] = await Promise.all([
+		api.v4(query),
+		getDefaultBranch()
+	]);
+
+	for (const prLink of prLinks) {
+		const pr: BranchInfo = data.repository[prLink.id];
+		if (pr.baseRefName === defaultBranch) {
+			continue;
+		}
+
+		const branch = pr.baseRef && `/${currentRepository.owner!}/${currentRepository.name!}/tree/${pr.baseRefName}`;
+
+		prLink.parentElement!.querySelector('.text-small.text-gray')!.append(
+			<span className="issue-meta-section d-inline-block">
+				<PullRequestIcon/>
+				{' To '}
+				<span
+					className="commit-ref css-truncate user-select-contain mb-n1"
+					style={(branch ? {} : {textDecoration: 'line-through'})}
+				>
+					<a title={branch ? pr.baseRefName : 'Deleted'} href={branch}>
+						{pr.baseRefName}
+					</a>
+				</span>
+			</span>
+		);
+	}
+}
+
+void features.add({
+	id: __filebasename,
+	description: 'Shows the base branch in PR lists if it’s not the default branch.',
+	screenshot: 'https://user-images.githubusercontent.com/1402241/88480306-39f4d700-cf4d-11ea-9e40-2b36d92d41aa.png'
+}, {
+	include: [
+		pageDetect.isRepoConversationList
+	],
+	init
+});
diff --git a/source/features/pr-branches.tsx b/source/features/pr-branches.tsx
diff --git a/source/refined-github.ts b/source/refined-github.ts
@@ -100,7 +100,7 @@ import './features/show-followers-you-know';
 import './features/show-user-top-repositories';
 import './features/set-default-repositories-type-to-sources';
 import './features/user-profile-follower-badge';
-import './features/pr-branches';
+import './features/highlight-non-default-base-branch';
 import './features/mark-private-orgs';
 import './features/linkify-commit-sha';
 import './features/bypass-checks';