refactor: apply review suggestions

Signed-off-by: Camila Belo <camilaibs@gmail.com>

packages/backend-test-utils/api-report.md

@@ -3,8 +3,10 @@
 > Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
 
 ```ts
+/// <reference types="express" />
 /// <reference types="jest" />
 /// <reference types="node" />
+/// <reference types="qs" />
 
 import { AuthService } from '@backstage/backend-plugin-api';
 import { Backend } from '@backstage/backend-app-api';
@@ -18,6 +20,7 @@ import { BackstageUserPrincipal } from '@backstage/backend-plugin-api';
 import { CacheService } from '@backstage/backend-plugin-api';
 import { DatabaseService } from '@backstage/backend-plugin-api';
 import { DiscoveryService } from '@backstage/backend-plugin-api';
+import { ErrorRequestHandler } from 'express';
 import { EventsService } from '@backstage/plugin-events-node';
 import { ExtendedHttpServer } from '@backstage/backend-defaults/rootHttpRouter';
 import { ExtensionPoint } from '@backstage/backend-plugin-api';
@@ -29,6 +32,8 @@ import Keyv from 'keyv';
 import { Knex } from 'knex';
 import { LifecycleService } from '@backstage/backend-plugin-api';
 import { LoggerService } from '@backstage/backend-plugin-api';
+import { ParamsDictionary } from 'express-serve-static-core';
+import { ParsedQs } from 'qs';
 import { PermissionsService } from '@backstage/backend-plugin-api';
 import { RootConfigService } from '@backstage/backend-plugin-api';
 import { RootHealthService } from '@backstage/backend-plugin-api';
@@ -139,6 +144,15 @@ export interface MockDirectoryContentOptions {
   shouldReadAsText?: boolean | ((path: string, buffer: Buffer) => boolean);
 }
 
+// @public
+export function mockErrorHandler(): ErrorRequestHandler<
+  ParamsDictionary,
+  any,
+  any,
+  ParsedQs,
+  Record<string, any>
+>;
+
 // @public (undocumented)
 export namespace mockServices {
   // (undocumented)

packages/backend-test-utils/package.json

@@ -55,7 +55,10 @@
     "@backstage/types": "workspace:^",
     "@keyv/memcache": "^1.3.5",
     "@keyv/redis": "^2.5.3",
+    "@types/express": "^4.17.6",
+    "@types/express-serve-static-core": "^4.17.5",
     "@types/keyv": "^4.2.0",
+    "@types/qs": "^6.9.6",
     "better-sqlite3": "^11.0.0",
     "cookie": "^0.6.0",
     "express": "^4.17.1",

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

@@ -25,3 +25,4 @@ export * from './database';
 export * from './msw';
 export * from './filesystem';
 export * from './next';
+export { mockErrorHandler } from './util';

packages/backend-test-utils/src/util/errorHandler.ts

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2024 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 { MiddlewareFactory } from '@backstage/backend-defaults/rootHttpRouter';
+import { mockServices } from '../next';
+
+/**
+ * A mock for error handler middleware that can be used in router tests.
+ * @public
+ */
+export function mockErrorHandler() {
+  return MiddlewareFactory.create({
+    config: mockServices.rootConfig(),
+    logger: mockServices.rootLogger(),
+  }).error();
+}

packages/backend-test-utils/src/util/index.ts

@@ -14,4 +14,5 @@
  * limitations under the License.
  */
 
+export { mockErrorHandler } from './errorHandler';
 export { isDockerDisabledForTests } from './isDockerDisabledForTests';