Write a test for pathRewrite

Signed-off-by: Karan Shah <karan.shah@simplybusiness.co.uk>

plugins/airbrake-backend/src/service/router.test.ts

@@ -18,13 +18,20 @@ import { getVoidLogger } from '@backstage/backend-common';
 import express from 'express';
 import request from 'supertest';
 import { ConfigReader } from '@backstage/config';
-import { createRouter } from './router';
-import { extractAirbrakeConfig } from '../config';
+import {
+  createRouter,
+  generateAirbrakePathRewrite,
+  RouterOptions,
+} from './router';
+import { AirbrakeConfig, extractAirbrakeConfig } from '../config';
 
 describe('createRouter', () => {
   let app: express.Express;
+  let airbrakeConfig: AirbrakeConfig;
+
+  beforeEach(async () => {
+    jest.resetAllMocks();
 
-  beforeAll(async () => {
     const config = new ConfigReader({
       integrations: {
         airbrake: {
@@ -32,7 +39,7 @@ describe('createRouter', () => {
         },
       },
     });
-    const airbrakeConfig = extractAirbrakeConfig(config);
+    airbrakeConfig = extractAirbrakeConfig(config);
 
     const router = await createRouter({
       logger: getVoidLogger(),
@@ -41,10 +48,6 @@ describe('createRouter', () => {
     app = express().use(router);
   });
 
-  beforeEach(() => {
-    jest.resetAllMocks();
-  });
-
   describe('GET /health', () => {
     it('returns ok', async () => {
       const response = await request(app).get('/health');
@@ -53,4 +56,20 @@ describe('createRouter', () => {
       expect(response.body).toEqual({ status: 'ok' });
     });
   });
+
+  describe('GET /api', () => {
+    it('appends the API Key properly', () => {
+      const options: RouterOptions = {
+        logger: getVoidLogger(),
+        airbrakeConfig,
+      };
+      const pathRewrite = generateAirbrakePathRewrite(options) as (
+        path: string,
+      ) => string;
+
+      expect(pathRewrite('/airbrake-backend/api/random/endpoint')).toBe(
+        '/random/endpoint?key=fakeApiKey',
+      );
+    });
+  });
 });

plugins/airbrake-backend/src/service/router.ts

@@ -20,12 +20,29 @@ import Router from 'express-promise-router';
 import { Logger } from 'winston';
 import { createProxyMiddleware } from 'http-proxy-middleware';
 import { AirbrakeConfig } from '../config';
+import { Options } from 'http-proxy-middleware/dist/types';
 
 export interface RouterOptions {
   logger: Logger;
   airbrakeConfig: AirbrakeConfig;
 }
 
+export const generateAirbrakePathRewrite = (
+  options: RouterOptions,
+): Options['pathRewrite'] => {
+  const apiKey = options.airbrakeConfig.apiKey;
+
+  return path => {
+    let newPath = path.replace(/.+?(\/api)/, '');
+    if (newPath.includes('?')) {
+      newPath += `&key=${apiKey}`;
+    } else {
+      newPath += `?key=${apiKey}`;
+    }
+    return newPath;
+  };
+};
+
 export async function createRouter(
   options: RouterOptions,
 ): Promise<express.Router> {
@@ -44,17 +61,7 @@ export async function createRouter(
     createProxyMiddleware({
       target: 'https://api.airbrake.io/api',
       changeOrigin: true,
-      pathRewrite: path => {
-        const apiKey = options.airbrakeConfig.apiKey;
-
-        let newPath = path.replace(/.+?(\/api)/, '');
-        if (newPath.includes('?')) {
-          newPath += `&key=${apiKey}`;
-        } else {
-          newPath += `?key=${apiKey}`;
-        }
-        return newPath;
-      },
+      pathRewrite: generateAirbrakePathRewrite(options),
     }),
   );