fix(@schematics/angular): add missing express REQUEST and RESPONSE tokens

This commit updates the nguniversal migration to add `REQUEST` and `RESPONSE` tokens.

Closes #26110

Author: alan-agius4

packages/schematics/angular/migrations/update-17/replace-nguniversal-engines.ts

@@ -6,6 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import { dirname, normalize, relative } from '@angular-devkit/core';
 import { DirEntry, Rule, chain } from '@angular-devkit/schematics';
 import { addDependency } from '../../utility';
 import { getPackageJsonDependency, removePackageJsonDependency } from '../../utility/dependencies';
@@ -81,17 +82,47 @@ export default function (): Rule {
             }
           }
 
-          // Replace server file
+          // Replace all import specifiers in all files.
+          let hasExpressTokens = false;
+          const root = project.sourceRoot ?? `${project.root}/src`;
+          const tokensFilePath = `/${root}/express.tokens.ts`;
+
+          for (const file of visit(tree.getDir(root))) {
+            const [path, content] = file;
+            let updatedContent = content;
+
+            // Check if file is importing tokens
+            if (content.includes('@nguniversal/express-engine/tokens')) {
+              hasExpressTokens ||= true;
+
+              let tokensFileRelativePath: string = relative(
+                dirname(normalize(path)),
+                normalize(tokensFilePath),
+              );
+
+              if (tokensFileRelativePath.charAt(0) !== '.') {
+                tokensFileRelativePath = './' + tokensFileRelativePath;
+              }
+
+              updatedContent = updatedContent.replaceAll(
+                '@nguniversal/express-engine/tokens',
+                tokensFileRelativePath.slice(0, -3),
+              );
+            }
+
+            updatedContent = updatedContent.replaceAll(NGUNIVERSAL_PACKAGE_REGEXP, '@angular/ssr');
+            tree.overwrite(path, updatedContent);
+          }
+
+          // Replace server file and add tokens file if needed
           for (const [path, outputPath] of serverMainFiles.entries()) {
             tree.rename(path, path + '.bak');
-            tree.create(path, getServerFileContents(outputPath));
-          }
-        }
+            tree.create(path, getServerFileContents(outputPath, hasExpressTokens));
 
-        // Replace all import specifiers in all files.
-        for (const file of visit(tree.root)) {
-          const [path, content] = file;
-          tree.overwrite(path, content.replaceAll(NGUNIVERSAL_PACKAGE_REGEXP, '@angular/ssr'));
+            if (hasExpressTokens) {
+              tree.create(tokensFilePath, TOKENS_FILE_CONTENT);
+            }
+          }
         }
 
         // Remove universal packages from deps.
@@ -104,16 +135,27 @@ export default function (): Rule {
   };
 }
 
-function getServerFileContents(outputPath: string): string {
-  return `
+const TOKENS_FILE_CONTENT = `
+import { InjectionToken } from '@angular/core';
+import { Request, Response } from 'express';
+
+export const REQUEST = new InjectionToken<Request>('REQUEST');
+export const RESPONSE = new InjectionToken<Response>('RESPONSE');
+`;
+
+function getServerFileContents(outputPath: string, hasExpressTokens: boolean): string {
+  return (
+    `
 import 'zone.js/node';
 
 import { APP_BASE_HREF } from '@angular/common';
 import { CommonEngine } from '@angular/ssr';
 import * as express from 'express';
 import { existsSync } from 'node:fs';
 import { join } from 'node:path';
-import bootstrap from './src/main.server';
+import bootstrap from './src/main.server';` +
+    (hasExpressTokens ? `\nimport { REQUEST, RESPONSE } from './src/express.tokens';` : '') +
+    `
 
 // The Express app is exported so that it can be used by serverless Functions.
 export function app(): express.Express {
@@ -145,7 +187,12 @@ export function app(): express.Express {
         documentFilePath: indexHtml,
         url: \`\${protocol}://\${headers.host}\${originalUrl}\`,
         publicPath: distFolder,
-        providers: [{ provide: APP_BASE_HREF, useValue: baseUrl }],
+        providers: [
+          { provide: APP_BASE_HREF, useValue: baseUrl },` +
+    (hasExpressTokens
+      ? '\n          { provide: RESPONSE, useValue: res },\n          { provide: REQUEST, useValue: req }\n'
+      : '') +
+    `],
       })
       .then((html) => res.send(html))
       .catch((err) => next(err));
@@ -175,5 +222,6 @@ if (moduleFilename === __filename || moduleFilename.includes('iisnode')) {
 }
 
 export default bootstrap;
-`;
+`
+  );
 }

packages/schematics/angular/migrations/update-17/replace-nguniversal-engines_spec.ts

@@ -16,7 +16,7 @@ function createWorkSpaceConfig(tree: UnitTestTree) {
     projects: {
       app: {
         root: '',
-        sourceRoot: '/src',
+        sourceRoot: 'src',
         projectType: ProjectType.Application,
         prefix: 'app',
         architect: {
@@ -181,20 +181,20 @@ if (moduleFilename === __filename || moduleFilename.includes('iisnode')) {
 
   it(`should replace imports from '@nguniversal/common' to '@angular/ssr'`, async () => {
     tree.create(
-      'file.ts',
+      'src/file.ts',
       `
       import { CommonEngine } from '@nguniversal/common';
       import { Component } from '@angular/core';
     `,
     );
 
     const newTree = await schematicRunner.runSchematic(schematicName, {}, tree);
-    expect(newTree.readContent('/file.ts')).toContain(
+    expect(newTree.readContent('src//file.ts')).toContain(
       `import { CommonEngine } from '@angular/ssr';`,
     );
   });
 
-  it(`should replace anf backup 'server.ts' file`, async () => {
+  it(`should replace and backup 'server.ts' file`, async () => {
     const newTree = await schematicRunner.runSchematic(schematicName, {}, tree);
     expect(newTree.readContent('server.ts.bak')).toContain(
       `import { ngExpressEngine } from '@nguniversal/express-engine';`,
@@ -204,4 +204,29 @@ if (moduleFilename === __filename || moduleFilename.includes('iisnode')) {
     expect(newServerFile).toContain(`import { CommonEngine } from '@angular/ssr';`);
     expect(newServerFile).toContain(`const distFolder = join(process.cwd(), 'dist/browser');`);
   });
+
+  it(`should create tokens file and replace usages of '@nguniversal/express-engine/tokens'`, async () => {
+    const filePath = 'src/tokens-usage.ts';
+    tree.create(filePath, `import {RESPONSE} from '@nguniversal/express-engine/tokens';`);
+
+    const newTree = await schematicRunner.runSchematic(schematicName, {}, tree);
+    expect(tree.readContent(filePath)).toContain(`import {RESPONSE} from './express.tokens';`);
+
+    const newServerFile = newTree.readContent('server.ts');
+    expect(newServerFile).toContain(`{ provide: RESPONSE, useValue: res }`);
+    expect(newServerFile).toContain(`import { REQUEST, RESPONSE } from './src/express.tokens';`);
+
+    expect(newTree.exists('src/express.tokens.ts')).toBeTrue();
+  });
+
+  it(`should not create tokens file when '@nguniversal/express-engine/tokens' is not used`, async () => {
+    const newTree = await schematicRunner.runSchematic(schematicName, {}, tree);
+    const newServerFile = newTree.readContent('server.ts');
+    expect(newServerFile).not.toContain(`{ provide: RESPONSE, useValue: res }`);
+    expect(newServerFile).not.toContain(
+      `import { REQUEST, RESPONSE } from './src/express.tokens';`,
+    );
+
+    expect(newTree.exists('src/express.tokens.ts')).toBeFalse();
+  });
 });