Prefer non recursive watch outside rootDir and node_modules if host p…

…refers it

src/compiler/resolutionCache.ts

@@ -192,6 +192,7 @@ export interface ResolutionCacheHost extends MinimalResolutionCacheHost {
     toPath(fileName: string): Path;
     getCanonicalFileName: GetCanonicalFileName;
     getCompilationSettings(): CompilerOptions;
+    preferNonRecursiveWatch: boolean | undefined;
     watchDirectoryOfFailedLookupLocation(directory: string, cb: DirectoryWatcherCallback, flags: WatchDirectoryFlags): FileWatcher;
     watchAffectingFileLocation(file: string, cb: FileWatcherCallback): FileWatcher;
     onInvalidatedResolution(): void;
@@ -351,6 +352,7 @@ export function getDirectoryToWatchFailedLookupLocation(
     rootPath: Path,
     rootPathComponents: Readonly<PathPathComponents>,
     getCurrentDirectory: () => string | undefined,
+    preferNonRecursiveWatch: boolean | undefined,
 ): DirectoryOfFailedLookupWatch | undefined {
     const failedLookupPathComponents: Readonly<PathPathComponents> = getPathComponents(failedLookupLocationPath);
     // Ensure failed look up is normalized path
@@ -390,6 +392,7 @@ export function getDirectoryToWatchFailedLookupLocation(
         nodeModulesIndex,
         rootPathComponents,
         lastNodeModulesIndex,
+        preferNonRecursiveWatch,
     );
 }
 
@@ -401,6 +404,7 @@ function getDirectoryToWatchFromFailedLookupLocationDirectory(
     nodeModulesIndex: number,
     rootPathComponents: Readonly<PathPathComponents>,
     lastNodeModulesIndex: number,
+    preferNonRecursiveWatch: boolean | undefined,
 ): DirectoryOfFailedLookupWatch | undefined {
     // If directory path contains node module, get the most parent node_modules directory for watching
     if (nodeModulesIndex !== -1) {
@@ -412,14 +416,17 @@ function getDirectoryToWatchFromFailedLookupLocationDirectory(
             lastNodeModulesIndex,
         );
     }
+
     // Use some ancestor of the root directory
     let nonRecursive = true;
     let length = dirPathComponentsLength;
-    for (let i = 0; i < dirPathComponentsLength; i++) {
-        if (dirPathComponents[i] !== rootPathComponents[i]) {
-            nonRecursive = false;
-            length = Math.max(i + 1, perceivedOsRootLength + 1);
-            break;
+    if (!preferNonRecursiveWatch) {
+        for (let i = 0; i < dirPathComponentsLength; i++) {
+            if (dirPathComponents[i] !== rootPathComponents[i]) {
+                nonRecursive = false;
+                length = Math.max(i + 1, perceivedOsRootLength + 1);
+                break;
+            }
         }
     }
     return getDirectoryOfFailedLookupWatch(
@@ -463,6 +470,7 @@ export function getDirectoryToWatchFailedLookupLocationFromTypeRoot(
     rootPath: Path,
     rootPathComponents: Readonly<PathPathComponents>,
     getCurrentDirectory: () => string | undefined,
+    preferNonRecursiveWatch: boolean | undefined,
     filterCustomPath: (path: Path) => boolean, // Return true if this path can be used
 ): Path | undefined {
     const typeRootPathComponents = getPathComponents(typeRootPath);
@@ -479,6 +487,7 @@ export function getDirectoryToWatchFailedLookupLocationFromTypeRoot(
         typeRootPathComponents.indexOf("node_modules" as Path),
         rootPathComponents,
         typeRootPathComponents.lastIndexOf("node_modules" as Path),
+        preferNonRecursiveWatch,
     );
     return toWatch && filterCustomPath(toWatch.dirPath) ? toWatch.dirPath : undefined;
 }
@@ -1140,6 +1149,7 @@ export function createResolutionCache(resolutionHost: ResolutionCacheHost, rootD
             rootPath,
             rootPathComponents,
             getCurrentDirectory,
+            resolutionHost.preferNonRecursiveWatch,
         );
         if (toWatch) {
             const { dir, dirPath, nonRecursive, packageDir, packageDirPath } = toWatch;
@@ -1354,6 +1364,7 @@ export function createResolutionCache(resolutionHost: ResolutionCacheHost, rootD
             rootPath,
             rootPathComponents,
             getCurrentDirectory,
+            resolutionHost.preferNonRecursiveWatch,
         );
         if (toWatch) {
             const { dirPath, packageDirPath } = toWatch;
@@ -1662,6 +1673,7 @@ export function createResolutionCache(resolutionHost: ResolutionCacheHost, rootD
                     rootPath,
                     rootPathComponents,
                     getCurrentDirectory,
+                    resolutionHost.preferNonRecursiveWatch,
                     dirPath => directoryWatchesOfFailedLookups.has(dirPath) || dirPathToSymlinkPackageRefCount.has(dirPath),
                 );
                 if (dirPath) {

src/compiler/sys.ts

@@ -1409,6 +1409,7 @@ export interface System {
      */
     watchFile?(path: string, callback: FileWatcherCallback, pollingInterval?: number, options?: WatchOptions): FileWatcher;
     watchDirectory?(path: string, callback: DirectoryWatcherCallback, recursive?: boolean, options?: WatchOptions): FileWatcher;
+    /**@internal */ preferNonRecursiveWatch?: boolean;
     resolvePath(path: string): string;
     fileExists(path: string): boolean;
     directoryExists(path: string): boolean;
@@ -1534,6 +1535,7 @@ export let sys: System = (() => {
             writeFile,
             watchFile,
             watchDirectory,
+            preferNonRecursiveWatch: !fsSupportsRecursiveFsWatch,
             resolvePath: path => _path.resolve(path),
             fileExists,
             directoryExists,

src/compiler/watch.ts

@@ -666,6 +666,7 @@ export function createWatchHost(system = sys, reportWatchStatus?: WatchStatusRep
         watchDirectory: maybeBind(system, system.watchDirectory) || returnNoopFileWatcher,
         setTimeout: maybeBind(system, system.setTimeout) || noop,
         clearTimeout: maybeBind(system, system.clearTimeout) || noop,
+        preferNonRecursiveWatch: system.preferNonRecursiveWatch,
     };
 }
 

src/compiler/watchPublic.ts

@@ -169,6 +169,7 @@ export interface WatchHost {
     setTimeout?(callback: (...args: any[]) => void, ms: number, ...args: any[]): any;
     /** If provided, will be used to reset existing delayed compilation */
     clearTimeout?(timeoutId: any): void;
+    preferNonRecursiveWatch?: boolean;
 }
 export interface ProgramHost<T extends BuilderProgram> {
     /**
@@ -498,6 +499,7 @@ export function createWatchProgram<T extends BuilderProgram>(host: WatchCompiler
     compilerHost.toPath = toPath;
     compilerHost.getCompilationSettings = () => compilerOptions!;
     compilerHost.useSourceOfProjectReferenceRedirect = maybeBind(host, host.useSourceOfProjectReferenceRedirect);
+    compilerHost.preferNonRecursiveWatch = host.preferNonRecursiveWatch;
     compilerHost.watchDirectoryOfFailedLookupLocation = (dir, cb, flags) => watchDirectory(dir, cb, flags, watchOptions, WatchType.FailedLookupLocations);
     compilerHost.watchAffectingFileLocation = (file, cb) => watchFile(file, cb, PollingInterval.High, watchOptions, WatchType.AffectingFileLocation);
     compilerHost.watchTypeRootsDirectory = (dir, cb, flags) => watchDirectory(dir, cb, flags, watchOptions, WatchType.TypeRoots);

src/harness/incrementalUtils.ts

@@ -516,6 +516,7 @@ function verifyProgram(service: ts.server.ProjectService, project: ts.server.Pro
         fileIsOpen: project.fileIsOpen.bind(project),
         getCurrentProgram: () => project.getCurrentProgram(),
 
+        preferNonRecursiveWatch: project.preferNonRecursiveWatch,
         watchDirectoryOfFailedLookupLocation: ts.returnNoopFileWatcher,
         watchAffectingFileLocation: ts.returnNoopFileWatcher,
         onInvalidatedResolution: ts.noop,

src/server/editorServices.ts

@@ -1075,13 +1075,17 @@ 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 };
     });
@@ -1326,6 +1330,7 @@ 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;
 
@@ -1397,6 +1402,7 @@ export class ProjectService {
                 log,
                 getDetailWatchInfo,
             );
+        this.canUseWatchEvents = getCanUseWatchEvents(this, opts.canUseWatchEvents);
         opts.incrementalVerifier?.(this);
     }
 

src/server/project.ts

@@ -506,6 +506,7 @@ 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;
 
@@ -566,6 +567,7 @@ 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

@@ -20,6 +20,7 @@ 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;

src/testRunner/unittests/canWatch.ts

@@ -87,6 +87,7 @@ describe("unittests:: canWatch::", () => {
                                     root,
                                     rootPathCompoments,
                                     ts.returnUndefined,
+                                    preferNonRecursiveWatch,
                                 );
                                 pushRow(baseline, [testPath, result ? result.packageDir ?? result.dir : "", result ? `${!result.nonRecursive}` : "", result?.packageDir ? result.dir : ""], maxLengths);
                             });
@@ -116,6 +117,7 @@ describe("unittests:: canWatch::", () => {
                             root,
                             rootPathCompoments,
                             ts.returnUndefined,
+                            preferNonRecursiveWatch,
                             ts.returnTrue,
                         );
                         pushRow(baseline, [path, result !== undefined ? result : ""], maxLengths);

src/testRunner/unittests/helpers/tscWatch.ts

@@ -310,6 +310,7 @@ function verifyProgramStructureAndResolutionCache(
         getCompilationSettings: () => options,
         fileIsOpen: ts.returnFalse,
         getCurrentProgram: () => program,
+        preferNonRecursiveWatch: sys.preferNonRecursiveWatch,
 
         watchDirectoryOfFailedLookupLocation: ts.returnNoopFileWatcher,
         watchAffectingFileLocation: ts.returnNoopFileWatcher,

src/testRunner/unittests/helpers/virtualFileSystemWithWatch.ts

@@ -362,6 +362,7 @@ export class TestServerHost implements server.ServerHost, FormatDiagnosticsHost,
     watchDirectory: HostWatchDirectory;
     service?: server.ProjectService;
     osFlavor: TestServerHostOsFlavor;
+    preferNonRecursiveWatch: boolean;
     constructor(
         fileOrFolderorSymLinkList: FileOrFolderOrSymLinkMap | readonly FileOrFolderOrSymLink[],
         {
@@ -389,6 +390,7 @@ export class TestServerHost implements server.ServerHost, FormatDiagnosticsHost,
         this.runWithFallbackPolling = !!runWithFallbackPolling;
         const tscWatchFile = this.environmentVariables && this.environmentVariables.get("TSC_WATCHFILE");
         const tscWatchDirectory = this.environmentVariables && this.environmentVariables.get("TSC_WATCHDIRECTORY");
+        this.preferNonRecursiveWatch = this.osFlavor === TestServerHostOsFlavor.Linux;
         this.inodeWatching = this.osFlavor !== TestServerHostOsFlavor.Windows;
         if (this.inodeWatching) this.inodes = new Map();
 
@@ -404,7 +406,7 @@ export class TestServerHost implements server.ServerHost, FormatDiagnosticsHost,
             fileSystemEntryExists: this.fileSystemEntryExists.bind(this),
             useCaseSensitiveFileNames: this.useCaseSensitiveFileNames,
             getCurrentDirectory: this.getCurrentDirectory.bind(this),
-            fsSupportsRecursiveFsWatch: this.osFlavor !== TestServerHostOsFlavor.Linux,
+            fsSupportsRecursiveFsWatch: !this.preferNonRecursiveWatch,
             getAccessibleSortedChildDirectories: path => this.getDirectories(path),
             realpath: this.realpath.bind(this),
             tscWatchFile,

tests/baselines/reference/api/typescript.d.ts

@@ -2649,6 +2649,7 @@ declare namespace ts {
         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;
@@ -9634,6 +9635,7 @@ declare namespace ts {
         setTimeout?(callback: (...args: any[]) => void, ms: number, ...args: any[]): any;
         /** If provided, will be used to reset existing delayed compilation */
         clearTimeout?(timeoutId: any): void;
+        preferNonRecursiveWatch?: boolean;
     }
     interface ProgramHost<T extends BuilderProgram> {
         /**