fix(@angular-devkit/build-angular): add externalDependencies to server builders

Certain node packages depend on native bindings which cannot be bundled, with this fix we add a way to exclude these from being processed by the bundler.

Closes: #16348

Author: alan-agius4

packages/angular/cli/lib/config/schema.json

@@ -1889,6 +1889,14 @@
                 }
               ]
             },
+            "externalDependencies": {
+              "description": "Exclude the listed external dependencies from being bundled into the bundle. Instead, the created bundle relies on these dependencies to be available during runtime.",
+              "type": "array",
+              "items": {
+                "type": "string"
+              },
+              "default": []
+            },
             "statsJson": {
               "type": "boolean",
               "description": "Generates a 'stats.json' file which can be analyzed using tools such as 'webpack-bundle-analyzer'.",

packages/angular_devkit/build_angular/src/angular-cli-files/models/build-options.ts

@@ -10,7 +10,6 @@
 
 import { logging } from '@angular-devkit/core';
 import { ParsedConfiguration } from '@angular/compiler-cli';
-import { ScriptTarget } from 'typescript';
 import {
   AssetPatternClass,
   Budget,
@@ -49,6 +48,7 @@ export interface BuildOptions {
   i18nMissingTranslation?: I18NMissingTranslation;
   extractCss?: boolean;
   bundleDependencies?: boolean;
+  externalDependencies?: string[];
   watch?: boolean;
   outputHashing?: string;
   poll?: number;

packages/angular_devkit/build_angular/src/angular-cli-files/models/webpack-configs/server.ts

@@ -15,10 +15,15 @@ import { getSourceMapDevTool } from './utils';
  * @param wco Options which are include the build options and app config
  */
 export function getServerConfig(wco: WebpackConfigOptions): Configuration {
-  const extraPlugins = [];
-  if (wco.buildOptions.sourceMap) {
-    const { scripts, styles, hidden } = wco.buildOptions.sourceMap;
+  const {
+    sourceMap,
+    bundleDependencies,
+    externalDependencies = [],
+  } = wco.buildOptions;
 
+  const extraPlugins = [];
+  if (sourceMap) {
+    const { scripts, styles, hidden } = sourceMap;
     extraPlugins.push(getSourceMapDevTool(scripts || false, styles || false, hidden || false));
   }
 
@@ -39,13 +44,17 @@ export function getServerConfig(wco: WebpackConfigOptions): Configuration {
     node: false,
   };
 
-  if (!wco.buildOptions.bundleDependencies) {
+  if (bundleDependencies) {
+    config.externals = [...externalDependencies];
+  } else {
     config.externals = [
-      /^@angular/,
+      ...externalDependencies,
       (context: string, request: string, callback: (error?: null, result?: string) => void) => {
         // Absolute & Relative paths are not externals
-        if (/^\.{0,2}\//.test(request) || isAbsolute(request)) {
-          return callback();
+        if (request.startsWith('./') || isAbsolute(request)) {
+          callback();
+
+          return;
         }
 
         try {

packages/angular_devkit/build_angular/src/server/schema.json

@@ -218,7 +218,7 @@
       "x-deprecated": "Since version 9. This option has no effect on server platform."
     },
     "bundleDependencies": {
-      "description": "Available on server platform only. Which external dependencies to bundle into the module. By default, all of node_modules will be bundled.",
+      "description": "Which external dependencies to bundle into the bundle. By default, all of node_modules will be bundled.",
       "default": true,
       "oneOf": [
         {
@@ -233,6 +233,14 @@
         }
       ]
     },
+    "externalDependencies": {
+      "description": "Exclude the listed external dependencies from being bundled into the bundle. Instead, the created bundle relies on these dependencies to be available during runtime.",
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "default": []
+    },
     "statsJson": {
       "type": "boolean",
       "description": "Generates a 'stats.json' file which can be analyzed using tools such as 'webpack-bundle-analyzer'.",

packages/angular_devkit/build_angular/test/server/external_dependencies_spec_large.ts

@@ -0,0 +1,46 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import { Architect } from '@angular-devkit/architect';
+import { join, normalize, virtualFs } from '@angular-devkit/core';
+import { ServerBuilderOutput } from '../../src';
+import { createArchitect, host } from '../utils';
+
+
+describe('Server Builder external dependencies', () => {
+  const target = { project: 'app', target: 'server' };
+  let architect: Architect;
+
+  beforeEach(async () => {
+    await host.initialize().toPromise();
+    architect = (await createArchitect(host.root())).architect;
+  });
+  afterEach(async () => host.restore().toPromise());
+
+  const outputPath = normalize('dist-server');
+
+  it('should not bundle an given external dependency', async () => {
+    const overrides = {
+      bundleDependencies: true,
+      externalDependencies: [
+        '@angular/core',
+      ],
+    };
+
+    const run = await architect.scheduleTarget(target, overrides);
+    const output = await run.result as ServerBuilderOutput;
+    expect(output.success).toBe(true);
+
+    const fileName = join(outputPath, 'main.js');
+    const content = virtualFs.fileBufferToString(host.scopedSync().read(normalize(fileName)));
+    expect(content).toContain('require("@angular/core")');
+    expect(content).not.toContain('require("@angular/common")');
+
+    await run.stop();
+  });
+});