feat(@nguniversal/express-engine): add standalone support to ng add

This commit add support to run `ng add @nguniversal/express-engine` in a standalone application.

modules/express-engine/schematics/install/files/__serverFileName@stripTsExtension__.ts

@@ -3,10 +3,9 @@ import 'zone.js/node';
 import { APP_BASE_HREF } from '@angular/common';
 import { ngExpressEngine } from '@nguniversal/express-engine';
 import * as express from 'express';
-import { existsSync } from 'fs';
-import { join } from 'path';
-
-import { AppServerModule } from './src/<%= stripTsExtension(main) %>';
+import { existsSync } from 'node:fs';
+import { join } from 'node:path';
+import <% if (isStandalone) { %>bootstrap<% } else { %>{ AppServerModule }<% } %> from './src/<%= stripTsExtension(main) %>;
 
 // The Express app is exported so that it can be used by serverless Functions.
 export function app(): express.Express {
@@ -16,7 +15,7 @@ export function app(): express.Express {
 
   // Our Universal express-engine (found @ https://github.com/angular/universal/tree/main/modules/express-engine)
   server.engine('html', ngExpressEngine({
-    bootstrap: AppServerModule,
+    <% if (isStandalone) { %>bootstrap<% } else { %>bootstrap: AppServerModule<% } %>
   }));
 
   server.set('view engine', 'html');

modules/express-engine/schematics/install/index.spec.ts

@@ -6,6 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import { tags } from '@angular-devkit/core';
 import { Tree } from '@angular-devkit/schematics';
 import { SchematicTestRunner } from '@angular-devkit/schematics/testing';
 
@@ -27,34 +28,30 @@ describe('Universal Schematic', () => {
   });
 
   it('should add dependency: @nguniversal/express-engine', async () => {
-    const tree = await schematicRunner
-      .runSchematicAsync('ng-add', defaultOptions, appTree)
-      .toPromise();
+    const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
+
     const filePath = '/package.json';
     const contents = tree.readContent(filePath);
     expect(contents).toMatch(/"@nguniversal\/express-engine": "/);
   });
 
   it('should add dependency: express', async () => {
-    const tree = await schematicRunner
-      .runSchematicAsync('ng-add', defaultOptions, appTree)
-      .toPromise();
+    const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
+
     const filePath = '/package.json';
     const contents = tree.readContent(filePath);
     expect(contents).toMatch(/"express": "/);
   });
 
   it('should install npm dependencies', async () => {
-    await schematicRunner.runSchematicAsync('ng-add', defaultOptions, appTree).toPromise();
+    await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
     expect(schematicRunner.tasks.length).toBe(1);
     expect(schematicRunner.tasks[0].name).toBe('node-package');
     expect((schematicRunner.tasks[0].options as { command: string }).command).toBe('install');
   });
 
   it(`should update 'tsconfig.server.json' files with Express main file`, async () => {
-    const tree = await schematicRunner
-      .runSchematicAsync('ng-add', defaultOptions, appTree)
-      .toPromise();
+    const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
 
     const { files } = JSON.parse(
       tree
@@ -69,20 +66,62 @@ describe('Universal Schematic', () => {
   });
 
   it(`should add export to main file in 'server.ts'`, async () => {
-    const tree = await schematicRunner
-      .runSchematicAsync('ng-add', defaultOptions, appTree)
-      .toPromise();
+    const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
 
     const content = tree.readContent('/projects/test-app/server.ts');
     expect(content).toContain(`export * from './src/main.server'`);
   });
 
   it(`should add correct value to 'distFolder'`, async () => {
-    const tree = await schematicRunner
-      .runSchematicAsync('ng-add', defaultOptions, appTree)
-      .toPromise();
+    const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
 
     const content = tree.readContent('/projects/test-app/server.ts');
     expect(content).toContain(`const distFolder = join(process.cwd(), 'dist/test-app/browser');`);
   });
+
+  it(`should import 'AppServerModule' from 'main.server.ts'`, async () => {
+    const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
+
+    const filePath = '/projects/test-app/server.ts';
+    const content = tree.readContent(filePath);
+    expect(content).toContain(`import { AppServerModule } from './src/main.server;`);
+  });
+
+  it(`should pass 'AppServerModule' in the bootstrap parameter.`, async () => {
+    const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
+
+    const filePath = '/projects/test-app/server.ts';
+    const content = tree.readContent(filePath);
+    expect(tags.oneLine`${content}`).toContain(tags.oneLine`
+      ngExpressEngine({
+        bootstrap: AppServerModule
+      }));
+    `);
+  });
+
+  describe('standalone application', () => {
+    beforeEach(async () => {
+      appTree = await createTestApp({ standalone: true });
+    });
+
+    it(`should add default import to 'main.server.ts'`, async () => {
+      const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
+
+      const filePath = '/projects/test-app/server.ts';
+      const content = tree.readContent(filePath);
+      expect(content).toContain(`import bootstrap from './src/main.server;`);
+    });
+
+    it(`should pass 'AppServerModule' in the bootstrap parameter.`, async () => {
+      const tree = await schematicRunner.runSchematic('ng-add', defaultOptions, appTree);
+
+      const filePath = '/projects/test-app/server.ts';
+      const content = tree.readContent(filePath);
+      expect(tags.oneLine`${content}`).toContain(tags.oneLine`
+        ngExpressEngine({
+          bootstrap
+        }));
+      `);
+    });
+  });
 });

modules/express-engine/schematics/install/index.ts

@@ -23,6 +23,9 @@ import {
 import { Schema as UniversalOptions } from '@schematics/angular/universal/schema';
 import { DependencyType, addDependency, updateWorkspace } from '@schematics/angular/utility';
 import { JSONFile } from '@schematics/angular/utility/json-file';
+import { isStandaloneApp } from '@schematics/angular/utility/ng-ast-utils';
+import { targetBuildNotFoundError } from '@schematics/angular/utility/project-targets';
+import { BrowserBuilderOptions } from '@schematics/angular/utility/workspace-models';
 import * as ts from 'typescript';
 
 import {
@@ -276,7 +279,7 @@ function addDependencies(): Rule {
   };
 }
 
-function addServerFile(options: UniversalOptions): Rule {
+function addServerFile(options: UniversalOptions, isStandalone: boolean): Rule {
   return async (host) => {
     const project = await getProject(host, options.project);
     const browserDistDirectory = await getOutputPath(host, options.project, 'build');
@@ -288,6 +291,7 @@ function addServerFile(options: UniversalOptions): Rule {
           ...options,
           stripTsExtension,
           browserDistDirectory,
+          isStandalone,
         }),
         move(project.root),
       ]),
@@ -302,6 +306,15 @@ export default function (options: AddUniversalOptions): Rule {
       ...options,
       skipInstall: true,
     };
+    const clientBuildTarget = project.targets.get('build');
+    if (!clientBuildTarget) {
+      throw targetBuildNotFoundError();
+    }
+
+    const clientBuildOptions = (clientBuildTarget.options ||
+      {}) as unknown as BrowserBuilderOptions;
+
+    const isStandalone = isStandaloneApp(host, clientBuildOptions.main);
 
     delete universalOptions.serverFileName;
     delete universalOptions.serverPort;
@@ -313,8 +326,8 @@ export default function (options: AddUniversalOptions): Rule {
       addScriptsRule(options),
       updateServerTsConfigRule(options),
       updateWorkspaceConfigRule(options),
-      routingInitialNavigationRule(options),
-      addServerFile(options),
+      isStandalone ? noop() : routingInitialNavigationRule(options),
+      addServerFile(options, isStandalone),
       addDependencies(),
     ]);
   };

modules/express-engine/schematics/testing/test-app.ts

@@ -15,23 +15,19 @@ export const collectionPath = require.resolve('../collection.json');
 export async function createTestApp(appOptions = {}): Promise<UnitTestTree> {
   const baseRunner = new SchematicTestRunner('universal-schematics', collectionPath);
 
-  const tree = await baseRunner
-    .runExternalSchematicAsync('@schematics/angular', 'workspace', {
-      name: 'workspace',
-      version: '6.0.0',
-      newProjectRoot: 'projects',
-    })
-    .toPromise();
+  const tree = await baseRunner.runExternalSchematic('@schematics/angular', 'workspace', {
+    name: 'workspace',
+    version: '6.0.0',
+    newProjectRoot: 'projects',
+  });
 
-  return baseRunner
-    .runExternalSchematicAsync(
-      '@schematics/angular',
-      'application',
-      {
-        ...appOptions,
-        name: 'test-app',
-      },
-      tree,
-    )
-    .toPromise();
+  return baseRunner.runExternalSchematic(
+    '@schematics/angular',
+    'application',
+    {
+      ...appOptions,
+      name: 'test-app',
+    },
+    tree,
+  );
 }