feat(webpack): add option to opt out of watching buildable dependencies (#29984)

Add a `watchDependencies` options to the relevant webpack executors and
plugins to allow opting out of watching buildable dependencies.

## Current Behavior

## Expected Behavior

## Related Issue(s)

Fixes #29961

docs/generated/packages/angular/executors/dev-server.json

@@ -150,6 +150,11 @@
           "type": "string",
           "description": "The path to the middleware function. Relative to the workspace root."
         }
+      },
+      "watchDependencies": {
+        "type": "boolean",
+        "description": "Watch buildable dependencies and rebuild when they change.",
+        "default": true
       }
     },
     "additionalProperties": false,

docs/generated/packages/angular/executors/webpack-browser.json

@@ -561,6 +561,11 @@
         "type": "boolean",
         "description": "Read buildable libraries from source instead of building them separately.",
         "default": true
+      },
+      "watchDependencies": {
+        "type": "boolean",
+        "description": "Watch buildable dependencies and rebuild when they change.",
+        "default": true
       }
     },
     "additionalProperties": false,

docs/shared/packages/webpack/webpack-plugins.md

@@ -301,6 +301,12 @@ Type: `boolean`
 
 Watch for file changes.
 
+##### watchDependencies
+
+Type: `boolean`
+
+Watch for buildable dependencies and rebuild when they change. Default is `true`.
+
 #### Example
 
 ```js

packages/angular/src/builders/dev-server/dev-server.impl.ts

@@ -214,7 +214,8 @@ export function executeDevServerBuilder(
                         new WebpackNxBuildCoordinationPlugin(
                           `nx run-many --target=${
                             parsedBuildTarget.target
-                          } --projects=${workspaceDependencies.join(',')}`
+                          } --projects=${workspaceDependencies.join(',')}`,
+                          { skipWatchingDeps: !options.watchDependencies }
                         )
                       );
                     }
@@ -269,6 +270,7 @@ function getDelegateBuilderOptions(
 
   // delete extra option not supported by the delegate builder
   delete delegateBuilderOptions.buildLibsFromSource;
+  delete delegateBuilderOptions.watchDependencies;
 
   return delegateBuilderOptions;
 }

packages/angular/src/builders/dev-server/lib/normalize-options.ts

@@ -24,5 +24,6 @@ export function normalizeOptions(schema: Schema): NormalizedSchema {
     hmr: schema.hmr ?? (angularMajorVersion < 19 ? false : undefined),
     open: schema.open ?? false,
     ssl: schema.ssl ?? false,
+    watchDependencies: schema.watchDependencies ?? true,
   };
 }

packages/angular/src/builders/dev-server/schema.d.ts

@@ -21,6 +21,7 @@ interface BaseSchema {
   prebundle?: boolean | { exclude: string[] };
   buildLibsFromSource?: boolean;
   esbuildMiddleware?: string[];
+  watchDependencies?: boolean;
 }
 
 export type SchemaWithBrowserTarget = BaseSchema & {

packages/angular/src/builders/dev-server/schema.json

@@ -156,6 +156,11 @@
         "type": "string",
         "description": "The path to the middleware function. Relative to the workspace root."
       }
+    },
+    "watchDependencies": {
+      "type": "boolean",
+      "description": "Watch buildable dependencies and rebuild when they change.",
+      "default": true
     }
   },
   "additionalProperties": false,

packages/angular/src/builders/webpack-browser/schema.d.ts

@@ -6,8 +6,10 @@ export type BrowserBuilderSchema = Schema & {
   };
   indexHtmlTransformer?: string;
   buildLibsFromSource?: boolean;
+  watchDependencies?: boolean;
+
   /**
-   * @deprecated Use `indexHtmlTransformer` instead. It will be removed in Nx 20.
+   * @deprecated Use `indexHtmlTransformer` instead. It will be removed in Nx 21.
    */
   indexFileTransformer?: string;
 };

packages/angular/src/builders/webpack-browser/schema.json

@@ -464,6 +464,11 @@
       "type": "boolean",
       "description": "Read buildable libraries from source instead of building them separately.",
       "default": true
+    },
+    "watchDependencies": {
+      "type": "boolean",
+      "description": "Watch buildable dependencies and rebuild when they change.",
+      "default": true
     }
   },
   "additionalProperties": false,

packages/angular/src/builders/webpack-browser/webpack-browser.impl.ts

@@ -51,12 +51,14 @@ export function executeWebpackBrowserBuilder(
   context: import('@angular-devkit/architect').BuilderContext
 ): Observable<import('@angular-devkit/architect').BuilderOutput> {
   options.buildLibsFromSource ??= true;
+  options.watchDependencies ??= true;
 
   const {
     buildLibsFromSource,
     customWebpackConfig,
     indexHtmlTransformer,
     indexFileTransformer,
+    watchDependencies,
     ...delegateBuilderOptions
   } = options;
 
@@ -124,7 +126,7 @@ export function executeWebpackBrowserBuilder(
                   `nx run-many --target=${
                     context.target.target
                   } --projects=${workspaceDependencies.join(',')}`,
-                  skipInitialRun
+                  { skipInitialRun, skipWatchingDeps: !watchDependencies }
                 )
               );
             }

packages/webpack/src/plugins/nx-typescript-webpack-plugin/nx-tsconfig-paths-webpack-plugin.ts

@@ -46,7 +46,7 @@ export class NxTsconfigPathsWebpackPlugin {
 
   handleBuildLibsFromSource(
     config: Partial<WebpackOptionsNormalized | Configuration>,
-    options
+    options: NormalizedNxAppWebpackPluginOptions
   ): void {
     if (!options.buildLibsFromSource && options.targetName) {
       const remappedTarget =
@@ -75,7 +75,11 @@ export class NxTsconfigPathsWebpackPlugin {
 
         const buildCommand = `nx run-many --target=build --projects=${buildableDependencies}`;
 
-        config.plugins.push(new WebpackNxBuildCoordinationPlugin(buildCommand));
+        config.plugins.push(
+          new WebpackNxBuildCoordinationPlugin(buildCommand, {
+            skipWatchingDeps: options.watchDependencies === false,
+          })
+        );
       }
     }
   }

packages/webpack/src/plugins/nx-webpack-plugin/nx-app-webpack-plugin-options.ts

@@ -235,6 +235,10 @@ export interface NxAppWebpackPluginOptions {
    * Whether to rebase absolute path for assets in postcss cli resources.
    */
   rebaseRootRelative?: boolean;
+  /**
+   * Watch buildable dependencies and rebuild when they change.
+   */
+  watchDependencies?: boolean;
 }
 
 export interface NormalizedNxAppWebpackPluginOptions

packages/webpack/src/plugins/webpack-nx-build-coordination-plugin.ts

@@ -4,21 +4,42 @@ import { daemonClient, isDaemonEnabled } from 'nx/src/daemon/client/client';
 import { BatchFunctionRunner } from 'nx/src/command-line/watch/watch';
 import { output } from 'nx/src/utils/output';
 
+type PluginOptions = {
+  skipInitialBuild?: boolean;
+  skipWatchingDeps?: boolean;
+};
+
 export class WebpackNxBuildCoordinationPlugin {
   private currentlyRunning: 'none' | 'nx-build' | 'webpack-build' = 'none';
   private buildCmdProcess: ReturnType<typeof exec> | null = null;
 
-  constructor(private readonly buildCmd: string, skipInitialBuild?: boolean) {
+  constructor(buildCmd: string);
-    if (!skipInitialBuild) {
+  /**
+   * @deprecated Use the constructor with the `options` parameter instead.
+   */
+  constructor(buildCmd: string, skipInitialBuild?: boolean);
+  constructor(buildCmd: string, options?: PluginOptions);
+  constructor(
+    private readonly buildCmd: string,
+    skipInitialBuildOrOptions?: boolean | PluginOptions
+  ) {
+    const options =
+      typeof skipInitialBuildOrOptions === 'boolean'
+        ? { skipInitialBuild: skipInitialBuildOrOptions }
+        : skipInitialBuildOrOptions;
+
+    if (!options?.skipInitialBuild) {
       this.buildChangedProjects();
     }
-    if (isDaemonEnabled()) {
+    if (!options?.skipWatchingDeps) {
-      this.startWatchingBuildableLibs();
+      if (isDaemonEnabled()) {
-    } else {
+        this.startWatchingBuildableLibs();
-      output.warn({
+      } else {
-        title:
+        output.warn({
-          'Nx Daemon is not enabled. Buildable libs will not be rebuilt on file changes.',
+          title:
-      });
+            'Nx Daemon is not enabled. Buildable libs will not be rebuilt on file changes.',
+        });
+      }
     }
   }