@@ -8,7 +8,6 @@
 
 import type * as ParcelWatcher from '@parcel/watcher';
 import type * as Chokidar from 'chokidar';
-import { once } from 'node:events';
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import picomatch from 'picomatch';
@@ -1086,92 +1085,50 @@ async function createParcelWatcher(
   return buildWatcher;
 }
 
-/**
- * Manages selective node_modules watching for Chokidar.
- *
- * During Chokidar's initial scan, the allowed packages set is empty, causing Chokidar to prune the entire
- * node_modules directory immediately and avoid blocking the 'ready' event for minutes.
- * Packages are dynamically allowed and watched at the package root level as files are added via `watcher.add`.
- * Tracking files per package allows reference-counting so that package directories are unwatched when no
- * longer needed.
- */
-class ChokidarNodeModulesManager {
-  private readonly allowedPackages = new Map<string, Set<string>>();
-
-  constructor(private readonly isCaseSensitive: boolean) {}
-
-  registerPackage(
-    posixPath: string,
-    lookupKey: string,
-  ): { isPackage: boolean; newPkgDir?: string } {
-    const packageDir = extractNodeModulesPackageDir(posixPath);
-    if (!packageDir) {
-      return { isPackage: false };
-    }
-
-    const packageKey = toLookupKey(packageDir, this.isCaseSensitive);
-    let watchedInPkg = this.allowedPackages.get(packageKey);
-    if (!watchedInPkg) {
-      watchedInPkg = new Set();
-      this.allowedPackages.set(packageKey, watchedInPkg);
-      watchedInPkg.add(lookupKey);
-
-      return { isPackage: true, newPkgDir: packageDir };
-    }
-
-    watchedInPkg.add(lookupKey);
-
-    return { isPackage: true };
-  }
-
-  removePackageFile(
-    posixPath: string,
-    lookupKey: string,
-  ): { isPackage: boolean; unwatchPkgDir?: string } {
-    const packageDir = extractNodeModulesPackageDir(posixPath);
-    if (!packageDir) {
-      return { isPackage: false };
-    }
-
-    const packageKey = toLookupKey(packageDir, this.isCaseSensitive);
-    const watchedInPkg = this.allowedPackages.get(packageKey);
-    if (watchedInPkg) {
-      watchedInPkg.delete(lookupKey);
-      if (watchedInPkg.size === 0) {
-        this.allowedPackages.delete(packageKey);
-
-        return { isPackage: true, unwatchPkgDir: packageDir };
-      }
-    }
-
-    return { isPackage: true };
-  }
-
-  isIgnored(filePath: string): boolean {
-    // Fast path: avoid expensive normalization for non-node_modules files
-    if (!filePath.includes(NODE_MODULES)) {
-      return false;
-    }
+function createChokidarIgnored(
+  ignoredPatterns: string[] | undefined,
+  isCaseSensitive: boolean,
+  watchedFiles: ReadonlySet<string>,
+): Chokidar.Matcher[] {
+  // Strip static node_modules ignore patterns (e.g. `**/node_modules/**` from setupWatcher).
+  // If left in place, picomatch would unconditionally ignore all node_modules files and prevent
+  // watching explicitly added files inside node_modules.
+  const customIgnored =
+    ignoredPatterns
+      ?.filter((pattern) => {
+        const base = toPosixPathNormalized(pattern).replace(/\/\*\*$/, '');
 
-    const posixPath = toPosixPathNormalized(filePath);
-    const lookupKey = toLookupKey(posixPath, this.isCaseSensitive);
+        return base !== NODE_MODULES && !base.endsWith(`/${NODE_MODULES}`);
+      })
+      .map((pattern) => {
+        if (/[*?[\]{}()]/.test(pattern)) {
+          const isMatch = picomatch(pattern, { dot: true });
 
-    if (!`${lookupKey}/`.includes(NODE_MODULES_SEGMENT)) {
-      return false;
-    }
+          return (filePath: string) => isMatch(toPosixPathNormalized(filePath));
+        }
 
-    if (this.allowedPackages.has(lookupKey)) {
-      return false;
-    }
+        return { path: toPosixPathNormalized(pattern), recursive: true };
+      }) ?? [];
 
-    for (const pkg of this.allowedPackages.keys()) {
-      if (isPathInside(lookupKey, pkg)) {
+  // When watching a directory (e.g. projectRoot via NG_BUILD_WATCH_ROOT), prune `node_modules`
+  // directories unless explicitly added to `watchedFiles`. Explicitly added files inside
+  // `node_modules` do not end with `/node_modules` and remain watchable.
+  return [
+    ...customIgnored,
+    (filePath: string) => {
+      if (!filePath.includes(NODE_MODULES)) {
         return false;
       }
-    }
 
-    return true;
-  }
+      const posixPath = toPosixPathNormalized(filePath);
+      const lookupKey = toLookupKey(posixPath, isCaseSensitive);
+
+      return (
+        (lookupKey === NODE_MODULES || lookupKey.endsWith(`/${NODE_MODULES}`)) &&
+        !watchedFiles.has(lookupKey)
+      );
+    },
+  ];
 }
 
 async function createChokidarWatcher(
@@ -1181,57 +1138,30 @@ async function createChokidarWatcher(
   const chokidar = chokidarModule ?? (await import('chokidar'));
   const watchedFiles = new Set<string>();
   const fileStats = new Map<string, { mtimeMs: number; size: number }>();
+  const pendingTimers = new Set<ReturnType<typeof setTimeout>>();
 
-  let queue: WatcherQueue;
-  if (options?.polling) {
-    const pollingInterval = options.interval ?? 100;
-    const debounceMs = Math.min(250, Math.max(100, Math.ceil(pollingInterval * 1.5)));
-    const maxWaitMs = Math.max(500, debounceMs * 3);
-    queue = new WatcherQueue(debounceMs, maxWaitMs);
-  } else {
-    queue = new WatcherQueue();
-  }
+  const pollingInterval = options?.interval ?? 100;
+  const debounceMs = Math.min(250, Math.max(100, Math.ceil(pollingInterval * 1.5)));
+  const queue = options?.polling
+    ? new WatcherQueue(debounceMs, Math.max(500, debounceMs * 3))
+    : new WatcherQueue();
 
   const rootDir = options?.cwd ?? process.cwd();
   const isCaseSensitive = isFileSystemCaseSensitive(rootDir);
-  const rootDirPosix = toPosixPathNormalized(rootDir);
-  const rootDirLookupKey = toLookupKey(rootDirPosix, isCaseSensitive);
-
-  const nodeModulesManager = new ChokidarNodeModulesManager(isCaseSensitive);
+  const ignored = createChokidarIgnored(options?.ignored, isCaseSensitive, watchedFiles);
 
-  // Strip static node_modules ignore patterns (e.g. `**/node_modules/**` from setupWatcher).
-  // If left in place, picomatch would unconditionally ignore all node_modules files and override
-  // our dynamic package allowlist above.
-  const customIgnored =
-    options?.ignored
-      ?.filter((pattern) => !pattern.includes(NODE_MODULES))
-      .map((pattern) => {
-        if (/[*?[\]{}()]/.test(pattern)) {
-          const isMatch = picomatch(pattern, { dot: true });
-
-          return (filePath: string) => isMatch(toPosixPathNormalized(filePath));
-        }
-
-        return { path: toPosixPathNormalized(pattern), recursive: true };
-      }) ?? [];
-
-  const ignored = [...customIgnored, (filePath: string) => nodeModulesManager.isIgnored(filePath)];
-
-  const watcher = chokidar.watch(rootDir, {
+  const watcher = chokidar.watch([], {
     ignoreInitial: true,
     ignored,
     followSymlinks: options?.followSymlinks,
     usePolling: !!options?.polling,
     interval: options?.interval,
   });
 
-  const initTime = Date.now();
+  // Prevent unhandled watcher errors (such as EMFILE or EACCES) from crashing the process.
+  watcher.on('error', () => {});
 
-  // Wait for the watcher to complete its initial filesystem scan before returning.
-  // With `ignoreInitial: true`, any file visited during the initial scan is treated as the initial baseline
-  // and will not emit 'add' or 'change' events. Awaiting 'ready' ensures that rapid file modifications
-  // made right after watcher setup (e.g. in rebuild tests) are not swallowed as initial files.
-  await once(watcher, 'ready');
+  const initTime = Date.now();
 
   const handleEvent = (type: 'added' | 'modified' | 'removed', rawPath: string) => {
     const posixPath = toPosixPathNormalized(rawPath);
@@ -1248,14 +1178,10 @@ async function createChokidarWatcher(
     }
 
     const stat = fs.statSync(rawPath, { throwIfNoEntry: false });
-    if (!stat) {
-      return;
-    }
-
     // Ignore historical events from before watcher initialization, but allow a 1000 ms window
     // to account for coarse filesystem timestamp resolution (e.g., ext4/overlayfs integer second
     // mtime truncation on Linux) where files modified during startup may have truncated .000 ms mtimes.
-    if (stat.mtimeMs < initTime - 1000) {
+    if (!stat || stat.mtimeMs < initTime - 1000) {
       return;
     }
 
@@ -1275,9 +1201,31 @@ async function createChokidarWatcher(
 
   watcher.on('add', (path) => handleEvent('added', path));
   watcher.on('change', (path) => handleEvent('modified', path));
-  watcher.on('unlink', (path) => handleEvent('removed', path));
+  watcher.on('unlink', (rawPath) => {
+    const posixPath = toPosixPathNormalized(rawPath);
+    const lookupKey = toLookupKey(posixPath, isCaseSensitive);
+    if (!isPathWatched(lookupKey, watchedFiles)) {
+      return;
+    }
 
-  const buildWatcher: BuildWatcher = {
+    // When Chokidar processes a file removal, it closes the underlying file watcher unless only a
+    // single directory is tracked (`_watched.size === 1`). Re-adding a directly watched path
+    // ensures Chokidar continues watching either the recreated file (if replaced within the atomic
+    // window) or its parent directory for future recreation.
+    if (watchedFiles.has(lookupKey)) {
+      fileStats.delete(lookupKey);
+      watcher.add(posixPath);
+      if (fs.existsSync(rawPath)) {
+        handleEvent('modified', rawPath);
+
+        return;
+      }
+    }
+
+    handleEvent('removed', rawPath);
+  });
+
+  return {
     [Symbol.asyncIterator]() {
       return this;
     },
@@ -1304,28 +1252,51 @@ async function createChokidarWatcher(
     add(paths) {
       const targets = typeof paths === 'string' ? [paths] : paths;
       const newPaths: string[] = [];
+      const baselineStats = new Map<string, { posixPath: string; mtimeMs: number; size: number }>();
+
       for (const p of targets) {
         const posixPath = toPosixPathNormalized(p);
         const lookupKey = toLookupKey(posixPath, isCaseSensitive);
         if (!watchedFiles.has(lookupKey)) {
           watchedFiles.add(lookupKey);
-
-          // For files inside node_modules, register their package directory. Only newly encountered
-          // package directories need to be added to Chokidar.
-          const { isPackage, newPkgDir } = nodeModulesManager.registerPackage(posixPath, lookupKey);
-          if (newPkgDir) {
-            newPaths.push(newPkgDir);
-          } else if (
-            !isPackage &&
-            !isPathInside(lookupKey, rootDirLookupKey) &&
-            lookupKey !== rootDirLookupKey
-          ) {
-            newPaths.push(posixPath);
+          newPaths.push(posixPath);
+          const stat = fs.statSync(posixPath, { throwIfNoEntry: false });
+          if (stat?.isFile()) {
+            baselineStats.set(lookupKey, { posixPath, mtimeMs: stat.mtimeMs, size: stat.size });
           }
         }
       }
       if (newPaths.length > 0) {
         watcher.add(newPaths);
+
+        if (baselineStats.size > 0) {
+          // Chokidar initializes file watchers asynchronously (`await stat(path)` followed by
+          // `fs.watch` or `fs.watchFile`). If a file is modified immediately after `add()` returns
+          // (for example, in tests that write to disk right after the initial build yields),
+          // Chokidar may capture the post-modification state as its initial baseline and miss the
+          // change. Re-statting after a short delay catches any modifications that occurred during
+          // asynchronous watcher registration, while `fileStats` deduplicates if Chokidar also fired.
+          const timer = setTimeout(() => {
+            pendingTimers.delete(timer);
+            void Promise.all(
+              Array.from(baselineStats, async ([lookupKey, baseline]) => {
+                if (!watchedFiles.has(lookupKey)) {
+                  return;
+                }
+                const currentStat = await fs.promises.stat(baseline.posixPath).catch(() => null);
+                if (
+                  watchedFiles.has(lookupKey) &&
+                  currentStat?.isFile() &&
+                  (currentStat.mtimeMs !== baseline.mtimeMs || currentStat.size !== baseline.size)
+                ) {
+                  handleEvent('modified', path.normalize(baseline.posixPath));
+                }
+              }),
+            );
+          }, 50);
+          timer.unref();
+          pendingTimers.add(timer);
+        }
       }
     },
 
@@ -1338,21 +1309,7 @@ async function createChokidarWatcher(
         if (watchedFiles.has(lookupKey)) {
           watchedFiles.delete(lookupKey);
           fileStats.delete(lookupKey);
-
-          // When the last watched file in a package is removed, unwatch the package directory.
-          const { isPackage, unwatchPkgDir } = nodeModulesManager.removePackageFile(
-            posixPath,
-            lookupKey,
-          );
-          if (unwatchPkgDir) {
-            removePaths.push(unwatchPkgDir);
-          } else if (
-            !isPackage &&
-            !isPathInside(lookupKey, rootDirLookupKey) &&
-            lookupKey !== rootDirLookupKey
-          ) {
-            removePaths.push(posixPath);
-          }
+          removePaths.push(posixPath);
         }
       }
       if (removePaths.length > 0) {
@@ -1361,13 +1318,15 @@ async function createChokidarWatcher(
     },
 
     async close() {
+      for (const timer of pendingTimers) {
+        clearTimeout(timer);
+      }
+      pendingTimers.clear();
       try {
         await watcher.close();
       } finally {
         queue.close();
       }
     },
-  };
-
-  return buildWatcher;
+  } satisfies BuildWatcher;
 }