feat(filesystem): honor the non-recursive watch option

CHANGELOG.md

@@ -19,6 +19,7 @@
 - [ai-ide] removed `WorkspaceFunctionScope.ensureWithinWorkspace(targetUri, workspaceRootUri)`. Every path-taking AI tool now resolves and checks its argument through `WorkspaceFunctionScope.resolveAccessiblePath(pathOrUri)`, which in addition to the workspace roots accepts locations covered by the `ai-features.workspaceFunctions.allowedExternalPaths` preference or contributed via the new `AccessibleRootContribution`. Adopters that called `ensureWithinWorkspace`, or `resolveRelativePath` followed by their own boundary check, should call `resolveAccessiblePath` instead [#17865](https://github.com/eclipse-theia/theia/pull/17865)
 - [core] added `onWindowLoaded` to the `SecondaryWindowService` interface; adopters implementing the interface from scratch (rather than extending `DefaultSecondaryWindowService`) must provide it [#17874](https://github.com/eclipse-theia/theia/pull/17874)
 - [core] many classes now inject `ILogger` in place of their raw `console` calls, so every container resolving them must provide it. This mainly affects tests, which can add `bind(ILogger).to(MockLogger)` using `MockLogger` from `@theia/core/lib/common/test/mock-logger` [#17763](https://github.com/eclipse-theia/theia/pull/17763)
+- [filesystem] `WatchOptions.recursive` is now honored by the backend watcher service, where it was previously ignored and every request became a recursive `@parcel/watcher` subscription. Non-recursive requests are served by a new `NodeDirectoryWatcher` that watches a single directory level with `fs.watch`, and requests resolving to the same directory share one watcher. `ParcelFileSystemWatcherService` is renamed to `FileSystemWatcherServiceImpl` and `PacelWatcherHandle` to `WatcherHandle`, both keeping a deprecated alias; the `watchers` map now holds a `WatcherInstance` of either kind, so adopters overriding `createWatcher` or `getWatcherKey`, or reading `watchers`, should check the new signatures [#17875](https://github.com/eclipse-theia/theia/pull/17875)
 - [monaco] removed the `protected secondaryWindowHandler` field from `MonacoFrontendApplicationContribution`; the Monaco theme stylesheet is now injected into every secondary window via `SecondaryWindowService.onWindowLoaded` [#17874](https://github.com/eclipse-theia/theia/pull/17874)
 - [plugin-ext] aliased `DebuggerContribution` to `PluginPackageDebuggersContribution` [#17758](https://github.com/eclipse-theia/theia/pull/17758)
 - [plugin-ext] changed `Keybinding.args` from `any` to `unknown` [#17758](https://github.com/eclipse-theia/theia/pull/17758)
@@ -27,6 +28,7 @@
 - [plugin-ext] moved `loadManifest` and `updateActivationEvents` to `@theia/plugin-utils` [#17758](https://github.com/eclipse-theia/theia/pull/17758)
 - [plugin-ext] rejected grammar paths outside the plugin directory [#17758](https://github.com/eclipse-theia/theia/pull/17758)
 - [plugin-ext] removed `buildFrontendModuleName` from `plugin-protocol` [#17758](https://github.com/eclipse-theia/theia/pull/17758)
+- [plugin-ext] removed the `workspaceService` constructor parameter and the `shouldSkipWatch` method from `MainFileSystemEventService`. They implemented a mitigation that dropped non-recursive plugin watches rooted above a workspace root, which is obsolete now that the backend honors `recursive` [#17875](https://github.com/eclipse-theia/theia/pull/17875)
 - [preferences] removed the `protected scopeTracker` field from `PreferencesContribution`, so the Settings widget is no longer constructed on startup. Adopters should read the scope via the new `protected currentScope` getter [#17877](https://github.com/eclipse-theia/theia/pull/17877)
 - [scm] widened `ScmHistoryItem.tooltip` from `string` to `string | MarkdownString | readonly MarkdownString[]`, so that hovers supplied by a history provider keep their `isTrusted` command allow-list and their multi-section form; adopters reading the field as a string must narrow it [#17880](https://github.com/eclipse-theia/theia/pull/17880)
 - [scm-extra] deprecated the `@theia/scm-extra` extension and stopped publishing it on npm; it has also been removed from the example applications, which drops its `SCM History` view, the `History` context menu items in the navigator and editor, and the `alt+h` keybinding. The view has been non-functional in the default application since the removal of `@theia/git`, as nothing implements `ScmHistorySupport` anymore. Please use the SCM history graph in `@theia/scm` for branch history and the Timeline view in `@theia/timeline` for per-file history instead [#17882](https://github.com/eclipse-theia/theia/pull/17882)

packages/filesystem/src/common/filesystem-watcher-protocol.ts

@@ -89,6 +89,10 @@ export interface FileSystemWatcherClient {
 
 export interface WatchOptions {
     ignored: string[];
+    /**
+     * Watch the whole subtree under the given path. Defaults to `true`.
+     */
+    recursive?: boolean;
 }
 export interface FileChange {
     uri: string;

packages/filesystem/src/node/disk-file-system-provider.ts

@@ -833,7 +833,8 @@ export class DiskFileSystemProvider implements Disposable,
         };
         watcherService.watchFileChanges(resource.toString(), {
             // Convert from `files.WatchOptions` to internal `watcher-protocol.WatchOptions`:
-            ignored: opts.excludes
+            ignored: opts.excludes,
+            recursive: opts.recursive
         }).then(watcherId => {
             if (handle.disposed) {
                 watcherService.unwatchFileChanges(watcherId);

packages/filesystem/src/node/filesystem-backend-module.ts

@@ -19,7 +19,7 @@ import { ContainerModule, interfaces } from '@theia/core/shared/inversify';
 import { ConnectionHandler, RpcConnectionHandler, ILogger } from '@theia/core/lib/common';
 import { FileSystemWatcherServer, FileSystemWatcherService } from '../common/filesystem-watcher-protocol';
 import { FileSystemWatcherServerClient } from './filesystem-watcher-client';
-import { ParcelFileSystemWatcherService, ParcelFileSystemWatcherServerOptions } from './parcel-watcher/parcel-filesystem-service';
+import { FileSystemWatcherServiceImpl, ParcelFileSystemWatcherServerOptions } from './parcel-watcher/parcel-filesystem-service';
 import { NodeFileUploadService } from './upload/node-file-upload-service';
 import { ParcelWatcherOptions } from './parcel-watcher/parcel-options';
 import { DiskFileSystemProvider } from './disk-file-system-provider';
@@ -38,11 +38,11 @@ export const WATCHER_VERBOSE = process.argv.includes('--watcher-verbose');
 
 export const FileSystemWatcherServiceProcessOptions = Symbol('FileSystemWatcherServiceProcessOptions');
 /**
- * Options to control the way the `ParcelFileSystemWatcherService` process is spawned.
+ * Options to control the way the `FileSystemWatcherServiceImpl` process is spawned.
  */
 export interface FileSystemWatcherServiceProcessOptions {
     /**
-     * Path to the script that will run the `ParcelFileSystemWatcherService` in a new process.
+     * Path to the script that will run the `FileSystemWatcherServiceImpl` in a new process.
      */
     entryPoint: string;
 }
@@ -102,7 +102,7 @@ export function bindFileSystemWatcherServer(bind: interfaces.Bind): void {
 export function createParcelFileSystemWatcherService(ctx: interfaces.Context): FileSystemWatcherService {
     const options = ctx.container.get<ParcelFileSystemWatcherServerOptions>(ParcelFileSystemWatcherServerOptions);
     const dispatcher = ctx.container.get<FileSystemWatcherServiceDispatcher>(FileSystemWatcherServiceDispatcher);
-    const server = new ParcelFileSystemWatcherService(options);
+    const server = new FileSystemWatcherServiceImpl(options);
     server.setClient(dispatcher);
     return server;
 }