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

src/vs/workbench/api/browser/mainThreadFileSystem.ts

@@ -17,6 +17,7 @@ export class MainThreadFileSystem implements MainThreadFileSystemShape {
 	private readonly _proxy: ExtHostFileSystemShape;
 	private readonly _fileProvider = new Map<number, RemoteFileSystemProvider>();
 	private readonly _disposables = new DisposableStore();
+	private readonly _watches = new Map<number, IDisposable>();
 
 	constructor(
 		extHostContext: IExtHostContext,
@@ -153,6 +154,19 @@ export class MainThreadFileSystem implements MainThreadFileSystemShape {
 	$ensureActivation(scheme: string): Promise<void> {
 		return this._fileService.activateProvider(scheme);
 	}
+
+	$watch(session: number, resource: UriComponents, opts: IWatchOptions): void {
+		const subscription = this._fileService.watch(URI.revive(resource), opts);
+		this._watches.set(session, subscription);
+	}
+
+	$unwatch(session: number): void {
+		const subscription = this._watches.get(session);
+		if (subscription) {
+			subscription.dispose();
+			this._watches.delete(session);
+		}
+	}
 }
 
 class RemoteFileSystemProvider implements IFileSystemProviderWithFileReadWriteCapability, IFileSystemProviderWithOpenReadWriteCloseCapability, IFileSystemProviderWithFileFolderCopyCapability {

src/vs/workbench/api/common/extHost.api.impl.ts

@@ -922,6 +922,10 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 			get fs() {
 				return extHostConsumerFileSystem.value;
 			},
+			get fs2() {
+				checkProposedApiEnabled(extension, 'fsWatch');
+				return extHostConsumerFileSystem.value as vscode.FileSystem2;
+			},
 			registerFileSearchProvider: (scheme: string, provider: vscode.FileSearchProvider) => {
 				checkProposedApiEnabled(extension, 'fileSearchProvider');
 				return extHostSearch.registerFileSearchProvider(scheme, provider);

src/vs/workbench/api/common/extHost.protocol.ts

@@ -1017,6 +1017,8 @@ export interface MainThreadFileSystemShape extends IDisposable {
 	$copy(resource: UriComponents, target: UriComponents, opts: files.FileOverwriteOptions): Promise<void>;
 	$mkdir(resource: UriComponents): Promise<void>;
 	$delete(resource: UriComponents, opts: files.FileDeleteOptions): Promise<void>;
+	$watch(session: number, resource: UriComponents, opts: files.IWatchOptions): void;
+	$unwatch(session: number): void;
 
 	$ensureActivation(scheme: string): Promise<void>;
 }

src/vs/workbench/api/common/extHostFileSystemConsumer.ts

@@ -131,6 +131,13 @@ export class ExtHostConsumerFileSystem {
 					return !(capabilities & files.FileSystemProviderCapabilities.Readonly);
 				}
 				return undefined;
+			},
+			watch(uri: vscode.Uri, options: { recursive: boolean; excludes: string[] } = { recursive: false, excludes: [] }): vscode.Disposable {
+				const session = Math.random();
+				that._proxy.$watch(session, uri, options);
+				return toDisposable(() => {
+					that._proxy.$unwatch(session);
+				});
 			}
 		});
 	}

src/vs/workbench/services/extensions/common/extensionsApiProposals.ts

@@ -23,6 +23,7 @@ export const allApiProposals = Object.freeze({
 	fileSearchProvider: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.fileSearchProvider.d.ts',
 	findTextInFiles: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.findTextInFiles.d.ts',
 	fsChunks: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.fsChunks.d.ts',
+	fsWatch: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.fsWatch.d.ts',
 	inlayHints: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.inlayHints.d.ts',
 	inlineCompletions: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.inlineCompletions.d.ts',
 	languageStatus: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.languageStatus.d.ts',

src/vscode-dts/vscode.proposed.fsWatch.d.ts

@@ -0,0 +1,42 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+declare module 'vscode' {
+
+	// https://github.com/microsoft/vscode/issues/3025
+
+	export interface FileSystem2 extends FileSystem {
+
+		/**
+		 * Subscribe to file change events in the file or folder denoted by `uri`. For folders,
+		 * the option `recursive` indicates whether subfolders, sub-subfolders, etc. should
+		 * be watched for file changes as well.
+		 *
+		 * The `excludes` array is used to indicate paths that should be excluded from file
+		 * watching. Each entry can be be:
+		 * - the absolute path to exclude
+		 * - a relative path to exclude (for example `build/output`)
+		 * - a simple glob pattern (for example `**\build`, `output/**`)
+		 *
+		 * File events will be delivered via {@linkcode workspace.createFileSystemWatcher createFileSystemWatcher}.
+		 *
+		 * @param uri The uri of the file or folder to be watched.
+		 * @param options Configures the watch.
+		 * @returns A disposable that tells the provider to stop watching the `uri`.
+		 */
+		watch(uri: Uri, options?: { recursive: boolean; excludes: string[] }): Disposable;
+	}
+
+	export namespace workspace {
+
+		/**
+		 * A {@link FileSystem file system} instance that allows to interact with local and remote
+		 * files, e.g. `vscode.workspace.fs.readDirectory(someUri)` allows to retrieve all entries
+		 * of a directory or `vscode.workspace.fs.stat(anotherUri)` returns the meta data for a
+		 * file.
+		 */
+		export const fs2: FileSystem2;
+	}
+}