API: Allow to use the file watcher for aribitrary folders (#3025) (#139881)

* API: Allow to use the file watcher for aribitrary folders (#3025)

* fix tests

* update `createFileSystemWatcher` docs

* refuse to watch resources that are watched in workspace already

* properly check proposed API

* make it work via `createFileSystemWacher` (first cut)

* more docs

* cleanup

* enable recursive watching based on pattern

* add tests

* drop out-of-workspace events when using simple patterns

* do not apply excludes when watchig files

* log extension watch requests

* also log unwatch

* improved exclude handling

* more docs

* drop proposed api needs

* remove `suite.only`

* cannot watch inside workspace more than once

* do not send extension decriptor over

* adopt latest changes

* add `baseUri` to relative pattern

* backwards compat

extensions/vscode-api-tests/src/singlefolder-tests/workspace.watcher.test.ts

@@ -0,0 +1,62 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import * as vscode from 'vscode';
+import { TestFS } from '../memfs';
+import { assertNoRpc } from '../utils';
+
+suite('vscode API - workspace-watcher', () => {
+
+	interface IWatchRequest {
+		uri: vscode.Uri;
+		options: { recursive: boolean; excludes: string[] }
+	}
+
+	class WatcherTestFs extends TestFS {
+
+		private _onDidWatch = new vscode.EventEmitter<IWatchRequest>();
+		readonly onDidWatch = this._onDidWatch.event;
+
+		override watch(uri: vscode.Uri, options: { recursive: boolean; excludes: string[] }): vscode.Disposable {
+			this._onDidWatch.fire({ uri, options });
+
+			return super.watch(uri, options);
+		}
+	}
+
+	teardown(assertNoRpc);
+
+	test('createFileSystemWatcher', async function () {
+		const fs = new WatcherTestFs('watcherTest', false);
+		vscode.workspace.registerFileSystemProvider('watcherTest', fs);
+
+		function onDidWatchPromise() {
+			const onDidWatchPromise = new Promise<IWatchRequest>(resolve => {
+				fs.onDidWatch(request => resolve(request));
+			});
+
+			return onDidWatchPromise;
+		}
+
+		// Non-recursive
+		let watchUri = vscode.Uri.from({ scheme: 'watcherTest', path: '/somePath/folder' });
+		const watcher = vscode.workspace.createFileSystemWatcher(new vscode.RelativePattern(watchUri, '*.txt'));
+		let request = await onDidWatchPromise();
+
+		assert.strictEqual(request.uri.toString(), watchUri.toString());
+		assert.strictEqual(request.options.recursive, false);
+
+		watcher.dispose();
+
+		// Recursive
+		watchUri = vscode.Uri.from({ scheme: 'watcherTest', path: '/somePath/folder' });
+		vscode.workspace.createFileSystemWatcher(new vscode.RelativePattern(watchUri, '**/*.txt'));
+		request = await onDidWatchPromise();
+
+		assert.strictEqual(request.uri.toString(), watchUri.toString());
+		assert.strictEqual(request.options.recursive, true);
+	});
+});