Merge from vscode 52dcb723a39ae75bee1bd56b3312d7fcdc87aeed (#6719)

extensions/git/src/watch.ts

@@ -0,0 +1,25 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Event, EventEmitter, Uri } from 'vscode';
+import { join } from 'path';
+import * as fs from 'fs';
+import { IDisposable } from './util';
+
+export interface IFileWatcher extends IDisposable {
+	readonly event: Event<Uri>;
+}
+
+export function watch(location: string): IFileWatcher {
+	const dotGitWatcher = fs.watch(location);
+	const onDotGitFileChangeEmitter = new EventEmitter<Uri>();
+	dotGitWatcher.on('change', (_, e) => onDotGitFileChangeEmitter.fire(Uri.file(join(location, e as string))));
+	dotGitWatcher.on('error', err => console.error(err));
+
+	return new class implements IFileWatcher {
+		event = onDotGitFileChangeEmitter.event;
+		dispose() { dotGitWatcher.close(); }
+	};
+}