On linux or editor with canUseEvents to prefer immediate directory if its not in root or node_modules (#58866)

src/server/editorServices.ts

@@ -1083,13 +1083,17 @@ function getHostWatcherMap<T>(): HostWatcherMap<T> {
     return { idToCallbacks: new Map(), pathToId: new Map() };
 }
 
+function getCanUseWatchEvents(service: ProjectService, canUseWatchEvents: boolean | undefined) {
+    return !!canUseWatchEvents && !!service.eventHandler && !!service.session;
+}
+
 function createWatchFactoryHostUsingWatchEvents(service: ProjectService, canUseWatchEvents: boolean | undefined): WatchFactoryHost | undefined {
-    if (!canUseWatchEvents || !service.eventHandler || !service.session) return undefined;
+    if (!getCanUseWatchEvents(service, canUseWatchEvents)) return undefined;
     const watchedFiles = getHostWatcherMap<FileWatcherCallback>();
     const watchedDirectories = getHostWatcherMap<DirectoryWatcherCallback>();
     const watchedDirectoriesRecursive = getHostWatcherMap<DirectoryWatcherCallback>();
     let ids = 1;
-    service.session.addProtocolHandler(protocol.CommandTypes.WatchChange, req => {
+    service.session!.addProtocolHandler(protocol.CommandTypes.WatchChange, req => {
         onWatchChange((req as protocol.WatchChangeRequest).arguments);
         return { responseRequired: false };
     });
@@ -1327,6 +1331,7 @@ export class ProjectService {
     /** @internal */ verifyDocumentRegistry = noop;
     /** @internal */ verifyProgram: (project: Project) => void = noop;
     /** @internal */ onProjectCreation: (project: Project) => void = noop;
+    /** @internal */ canUseWatchEvents: boolean;
 
     readonly jsDocParsingMode: JSDocParsingMode | undefined;
 
@@ -1396,6 +1401,7 @@ export class ProjectService {
                 log,
                 getDetailWatchInfo,
             );
+        this.canUseWatchEvents = getCanUseWatchEvents(this, opts.canUseWatchEvents);
         opts.incrementalVerifier?.(this);
     }
 

src/server/project.ts

@@ -555,6 +555,7 @@ export abstract class Project implements LanguageServiceHost, ModuleResolutionHo
     protected typeAcquisition: TypeAcquisition | undefined;
     /** @internal */
     createHash = maybeBind(this.projectService.host, this.projectService.host.createHash);
+    /** @internal*/ preferNonRecursiveWatch: boolean | undefined;
 
     readonly jsDocParsingMode: JSDocParsingMode | undefined;
 
@@ -615,6 +616,7 @@ export abstract class Project implements LanguageServiceHost, ModuleResolutionHo
             this.trace = s => host.trace!(s);
         }
         this.realpath = maybeBind(host, host.realpath);
+        this.preferNonRecursiveWatch = this.projectService.canUseWatchEvents || host.preferNonRecursiveWatch;
 
         // Use the current directory as resolution root only if the project created using current directory string
         this.resolutionCache = createResolutionCache(

src/server/types.ts

@@ -29,6 +29,7 @@ export type RequireResult = ModuleImportResult;
 export interface ServerHost extends System {
     watchFile(path: string, callback: FileWatcherCallback, pollingInterval?: number, options?: WatchOptions): FileWatcher;
     watchDirectory(path: string, callback: DirectoryWatcherCallback, recursive?: boolean, options?: WatchOptions): FileWatcher;
+    preferNonRecursiveWatch?: boolean;
     setTimeout(callback: (...args: any[]) => void, ms: number, ...args: any[]): any;
     clearTimeout(timeoutId: any): void;
     setImmediate(callback: (...args: any[]) => void, ...args: any[]): any;