chore: explore some of the options for the httpRouter and fix the shutdown in mutliple tests

Co-authored-by: Patrik Oldsberg <poldsberg@gmail.com>
Co-authored-by: Johan Haals <johan@haals.se>
Signed-off-by: blam <ben@blam.sh>

packages/backend-test-utils/package.json

@@ -40,6 +40,8 @@
     "@backstage/cli": "workspace:^",
     "@backstage/config": "workspace:^",
     "better-sqlite3": "^8.0.0",
+    "express": "^4.17.1",
+    "express-promise-router": "^4.1.0",
     "knex": "^2.0.0",
     "msw": "^0.49.0",
     "mysql2": "^2.2.5",
@@ -48,7 +50,9 @@
     "uuid": "^8.0.0"
   },
   "devDependencies": {
-    "@backstage/cli": "workspace:^"
+    "@backstage/cli": "workspace:^",
+    "@types/supertest": "^2.0.8",
+    "supertest": "^6.1.3"
   },
   "files": [
     "dist",

packages/backend-test-utils/src/next/implementations/index.ts

@@ -15,4 +15,3 @@
  */
 export { mockTokenManagerFactory } from './mockTokenManagerService';
 export { mockConfigFactory } from './mockConfigService';
-export { mockDiscoveryFactory } from './mockDiscoveryService';

packages/backend-test-utils/src/next/implementations/mockDiscoveryService.ts

@@ -1,40 +0,0 @@
-/*
- * Copyright 2023 The Backstage Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-import { SingleHostDiscovery } from '@backstage/backend-common';
-import {
-  coreServices,
-  createServiceFactory,
-} from '@backstage/backend-plugin-api';
-import { ConfigReader } from '@backstage/config';
-
-/** @public */
-export const mockDiscoveryFactory = createServiceFactory({
-  service: coreServices.discovery,
-  deps: {},
-  async factory() {
-    // todo(blam): we want to grab the port from the httpRouter when that's available here
-    // to provide a better way to create our mockDiscoveryService.
-    const discovery = SingleHostDiscovery.fromConfig(
-      new ConfigReader({
-        backend: { baseUrl: 'http://localhost:7007', listen: '0.0.0.0' },
-      }),
-    );
-
-    return async () => {
-      return discovery;
-    };
-  },
-});

packages/backend-test-utils/src/next/wiring/TestBackend.test.ts

@@ -22,6 +22,8 @@ import {
   coreServices,
   createBackendPlugin,
 } from '@backstage/backend-plugin-api';
+import { Router } from 'express';
+import request from 'supertest';
 
 import { startTestBackend } from './TestBackend';
 
@@ -184,7 +186,7 @@ describe('TestBackend', () => {
             urlReader: coreServices.urlReader,
           },
           async init(deps) {
-            expect(Object.keys(deps)).toHaveLength(14);
+            expect(Object.keys(deps)).toHaveLength(15);
             expect(Object.values(deps)).not.toContain(undefined);
           },
         });
@@ -194,6 +196,30 @@ describe('TestBackend', () => {
     await startTestBackend({
       services: [],
       features: [testPlugin()],
-    }).then(backend => backend.stop());
+    });
+  });
+
+  it('should allow making requests via supertest', async () => {
+    const testPlugin = createBackendPlugin({
+      id: 'test',
+      register(env) {
+        env.registerInit({
+          deps: {
+            httpRouter: coreServices.httpRouter,
+          },
+          async init({ httpRouter }) {
+            const router = Router();
+            router.use('/ping-me', (_, res) => res.json({ message: 'pong' }));
+            httpRouter.use(router);
+          },
+        });
+      },
+    });
+
+    const { server } = await startTestBackend({ features: [testPlugin()] });
+
+    const res = await request(server).get('/api/test/ping-me');
+    expect(res.status).toEqual(200);
+    expect(res.body).toEqual({ message: 'pong' });
   });
 });

packages/backend-test-utils/src/next/wiring/TestBackend.ts

@@ -26,23 +26,27 @@ import {
   schedulerFactory,
   urlReaderFactory,
   databaseFactory,
-  rootHttpRouterFactory,
   httpRouterFactory,
 } from '@backstage/backend-app-api';
-
+import {
+  createServiceBuilder,
+  SingleHostDiscovery,
+} from '@backstage/backend-common';
+import { Handler } from 'express';
+import * as http from 'http';
+import Router from 'express-promise-router';
 import {
   ServiceFactory,
   ServiceRef,
   createServiceFactory,
   BackendFeature,
   ExtensionPoint,
+  coreServices,
 } from '@backstage/backend-plugin-api';
 
-import {
-  mockConfigFactory,
-  mockTokenManagerFactory,
-  mockDiscoveryFactory,
-} from '../implementations';
+import { mockConfigFactory, mockTokenManagerFactory } from '../implementations';
+import { AddressInfo } from 'net';
+import { ConfigReader } from '@backstage/config';
 
 /** @alpha */
 export interface TestBackendOptions<
@@ -75,10 +79,8 @@ const defaultServiceFactories = [
   lifecycleFactory(),
   loggerFactory(),
   mockConfigFactory(),
-  mockDiscoveryFactory(),
   mockTokenManagerFactory(),
   permissionsFactory(),
-  rootHttpRouterFactory(),
   rootLifecycleFactory(),
   rootLoggerFactory(),
   schedulerFactory(),
@@ -99,6 +101,71 @@ export async function startTestBackend<
     ...otherOptions
   } = options;
 
+  let server: http.Server;
+
+  const rootHttpRouterFactory = createServiceFactory({
+    service: coreServices.rootHttpRouter,
+    deps: {
+      config: coreServices.config,
+      lifecycle: coreServices.rootLifecycle,
+    },
+    async factory({ config, lifecycle }) {
+      const router = Router();
+
+      const service = createServiceBuilder(module)
+        .loadConfig(config)
+        .setPort(0);
+
+      service.addRouter('', router);
+
+      server = await service.start();
+      // Stop method isn't part of the public API, let's fix that once we move the implementation here.
+      const stoppableServer = server as typeof server & {
+        stop: (cb: (error?: Error) => void) => void;
+      };
+
+      lifecycle.addShutdownHook({
+        async fn() {
+          await new Promise<void>((resolve, reject) => {
+            stoppableServer.stop((error?: Error) => {
+              if (error) {
+                reject(error);
+              } else {
+                resolve();
+              }
+            });
+          });
+        },
+        labels: { service: 'rootHttpRouter' },
+      });
+
+      return {
+        use: (path: string, handler: Handler) => {
+          router.use(path, handler);
+        },
+      };
+    },
+  });
+
+  const discoveryFactory = createServiceFactory({
+    service: coreServices.discovery,
+    deps: {
+      rootHttpRouter: coreServices.rootHttpRouter,
+    },
+    async factory() {
+      if (!server) {
+        throw new Error('Test server not started yet');
+      }
+      const { port } = server.address() as AddressInfo;
+      const discovery = SingleHostDiscovery.fromConfig(
+        new ConfigReader({
+          backend: { baseUrl: `http://localhost:${port}`, listen: { port } },
+        }),
+      );
+      return async () => discovery;
+    },
+  });
+
   const factories = services.map(serviceDef => {
     if (Array.isArray(serviceDef)) {
       // if type is ExtensionPoint?
@@ -131,7 +198,7 @@ export async function startTestBackend<
 
   const backend = createSpecializedBackend({
     ...otherOptions,
-    services: factories,
+    services: [...factories, rootHttpRouterFactory, discoveryFactory],
   });
 
   backendInstancesToCleanUp.push(backend);
@@ -153,7 +220,7 @@ export async function startTestBackend<
 
   await backend.start();
 
-  return backend;
+  return Object.assign(backend, { server: server! }) as Backend;
 }
 
 let registered = false;

yarn.lock

@@ -3558,11 +3558,15 @@ __metadata:
     "@backstage/backend-plugin-api": "workspace:^"
     "@backstage/cli": "workspace:^"
     "@backstage/config": "workspace:^"
+    "@types/supertest": ^2.0.8
     better-sqlite3: ^8.0.0
+    express: ^4.17.1
+    express-promise-router: ^4.1.0
     knex: ^2.0.0
     msw: ^0.49.0
     mysql2: ^2.2.5
     pg: ^8.3.0
+    supertest: ^6.1.3
     testcontainers: ^8.1.2
     uuid: ^8.0.0
   languageName: unknown