1 files changed, 52 insertions, 0 deletions
diff --git a/source/features/pr-commit-lines-changed.tsx b/source/features/pr-commit-lines-changed.tsx
new file mode 100644
index 00000000..fd38072f
--- /dev/null
+++ b/source/features/pr-commit-lines-changed.tsx
@@ -0,0 +1,52 @@
+import React from 'dom-chef';
+import cache from 'webext-storage-cache';
+import select from 'select-dom';
+import elementReady from 'element-ready';
+import * as api from '../libs/api';
+import features from '../libs/features';
+import {getRepoGQL, pluralize} from '../libs/utils';
+
+const getCommitChanges = cache.function(async (commit: string): Promise<[number, number]> => {
+	const {repository} = await api.v4(`
+		repository(${getRepoGQL()}) {
+			object(expression: "${commit}") {
+				... on Commit {
+					additions
+					deletions
+				}
+			}
+		}
+	`);
+
+	return [repository.object.additions, repository.object.deletions];
+}, {
+	cacheKey: ([commit]) => 'commit-changes:' + commit
+});
+
+async function init(): Promise<void> {
+	const commitSha = (await elementReady('.sha.user-select-contain'))!.textContent!;
+	const [additions, deletions] = await getCommitChanges(commitSha);
+	const tooltip = pluralize(additions + deletions, '1 line changed', '$$ lines changed');
+	select('.diffstat')!.replaceWith(
+		<span className="ml-2 diffstat tooltipped tooltipped-s" aria-label={tooltip}>
+			<span className="text-green">+{additions}</span>{' '}
+			<span className="text-red">−{deletions}</span>{' '}
+			<span className="diffstat-block-neutral"/>
+			<span className="diffstat-block-neutral"/>
+			<span className="diffstat-block-neutral"/>
+			<span className="diffstat-block-neutral"/>
+			<span className="diffstat-block-neutral"/>
+		</span>
+	);
+}
+
+features.add({
+	id: __featureName__,
+	description: 'Adds diff stats on PR commits.',
+	screenshot: 'https://user-images.githubusercontent.com/16872793/76107253-48deeb00-5fa6-11ea-9931-721cde553bdf.png',
+	include: [
+		features.isPRCommit
+	],
+	load: features.nowAndOnAjaxedPages,
+	init
+});