perf(@angular/build): replace watchpack with @parcel/watcher and chokidar

This change replaces the watchpack file watching dependency in @angular/build with @parcel/watcher as the primary native file watcher, while falling back to chokidar (v4) for polling or unsupported environments.

By leveraging @parcel/watcher's native C++ bindings (FSEvents, ReadDirectoryChangesW, inotify), file system watching is offloaded directly to OS kernel APIs, significantly reducing CPU and memory footprint during watch mode. Additionally, external directory watches are dynamically subsumed to minimize active native file handles, while early path filtering and event coalescing prevent redundant incremental rebuild triggers.

Author: clydin

package.json

@@ -89,7 +89,6 @@
     "@types/picomatch": "^4.0.0",
     "@types/progress": "^2.0.3",
     "@types/semver": "^7.3.12",
-    "@types/watchpack": "^2.4.4",
     "@types/yargs": "^17.0.20",
     "@types/yargs-parser": "^21.0.0",
     "@typescript-eslint/eslint-plugin": "8.65.0",

packages/angular/build/BUILD.bazel

@@ -86,9 +86,11 @@ ts_project(
         ":node_modules/@babel/helper-split-export-declaration",
         ":node_modules/@inquirer/confirm",
         ":node_modules/@oxc-project/types",
+        ":node_modules/@parcel/watcher",
         ":node_modules/@vitejs/plugin-basic-ssl",
         ":node_modules/beasties",
         ":node_modules/browserslist",
+        ":node_modules/chokidar",
         ":node_modules/https-proxy-agent",
         ":node_modules/istanbul-lib-instrument",
         ":node_modules/jsonc-parser",
@@ -110,7 +112,6 @@ ts_project(
         ":node_modules/tinyglobby",
         ":node_modules/vite",
         ":node_modules/vitest",
-        ":node_modules/watchpack",
         "//:node_modules/@angular/common",
         "//:node_modules/@angular/compiler",
         "//:node_modules/@angular/compiler-cli",
@@ -125,7 +126,6 @@ ts_project(
         "//:node_modules/@types/node",
         "//:node_modules/@types/picomatch",
         "//:node_modules/@types/semver",
-        "//:node_modules/@types/watchpack",
         "//:node_modules/esbuild",
         "//:node_modules/esbuild-wasm",
         "//:node_modules/karma",

packages/angular/build/package.json

@@ -43,7 +43,8 @@
     "source-map-support": "0.5.21",
     "tinyglobby": "0.2.17",
     "vite": "8.1.5",
-    "watchpack": "2.5.2"
+    "@parcel/watcher": "2.5.1",
+    "chokidar": "4.0.3"
   },
   "optionalDependencies": {
     "lmdb": "3.5.6"

packages/angular/build/src/builders/application/build-action.ts

@@ -113,11 +113,12 @@ export async function* runEsBuildBuildAction(
 
       // Setup a watcher
       const { createWatcher } = await import('../../tools/esbuild/watcher');
-      watcher = createWatcher({
+      watcher = await createWatcher({
         polling: typeof poll === 'number',
         interval: poll,
         followSymlinks: preserveSymlinks,
         ignored,
+        cwd: workspaceRoot,
       });
 
       // Setup abort support
@@ -215,6 +216,9 @@ export async function* runEsBuildBuildAction(
       // Remove any stale locations if the build was successful
       if (staleWatchFiles?.size) {
         watcher.remove([...staleWatchFiles]);
+        for (const staleFile of staleWatchFiles) {
+          currentWatchFiles.delete(staleFile);
+        }
       }
 
       for (const outputResult of emitOutputResults(