fix(@angular/build): show error when Node.js built-ins are used during ng serve

This commit ensures consistent behavior between `ng build` and `ng serve`. Previously, `ng serve` did not display an error message when Node.js built-in modules were included in browser bundles. By default, Vite replaces Node.js built-ins with empty modules, which can lead to unexpected runtime issues. This update addresses the problem by surfacing clear error messages, providing better developer feedback and alignment between the two commands.

Closes: #27425

Author: alan-agius4

packages/angular/build/src/builders/dev-server/vite-server.ts

@@ -803,6 +803,26 @@ function getDepOptimizationConfig({
   thirdPartySourcemaps: boolean;
 }): DepOptimizationConfig {
   const plugins: ViteEsBuildPlugin[] = [
+    {
+      name: 'angular-browser-node-built-in',
+      setup(build) {
+        // This namespace is configured by vite.
+        // @see: https://github.com/vitejs/vite/blob/a1dd396da856401a12c921d0cd2c4e97cb63f1b5/packages/vite/src/node/optimizer/esbuildDepPlugin.ts#L109
+        build.onLoad({ filter: /.*/, namespace: 'browser-external' }, (args) => {
+          if (!isBuiltin(args.path)) {
+            return;
+          }
+
+          return {
+            errors: [
+              {
+                text: `The package "${args.path}" wasn't found on the file system but is built into node.`,
+              },
+            ],
+          };
+        });
+      },
+    },
     {
       name: `angular-vite-optimize-deps${ssr ? '-ssr' : ''}${
         thirdPartySourcemaps ? '-vendor-sourcemap' : ''

tests/legacy-cli/e2e/tests/vite/browser-node-module-dep-error.ts

@@ -0,0 +1,21 @@
+import assert from 'node:assert';
+import { execAndWaitForOutputToMatch, ng } from '../../utils/process';
+import { writeFile } from '../../utils/fs';
+
+export default async function () {
+  await ng('cache', 'clean');
+  await ng('cache', 'on');
+
+  // The `@angular/cli` package relies on Node.js dependencies and is not designed for use in a browser environment.
+  await writeFile('src/main.ts', `import '@angular/cli';`);
+
+  const { stderr } = await execAndWaitForOutputToMatch('ng', ['serve', '--port=0'], /ERROR/, {
+    CI: '0',
+    NO_COLOR: 'true',
+  });
+
+  assert.match(
+    stderr,
+    /The package "node:util" wasn't found on the file system but is built into node/,
+  );
+}