Handle plural endpoints gracefully

backend/helpers/plural.endpoint.handler.test.ts

@@ -0,0 +1,34 @@
+import express from 'express';
+import { Request, Response } from 'express';
+import request from 'supertest';
+import { describe, expect } from '@jest/globals';
+
+import { pluralEndpointHandler } from './plural.endpoint.handler';
+import { HttpCode } from './constants';
+
+const app = express();
+const router = express.Router();
+
+router.route('/book').get((req: Request, res: Response) => {
+    return res.status(HttpCode.OK).send();
+});
+
+router.route('*').get((req, res) => {
+	return pluralEndpointHandler(req, res);
+});
+
+app.use(router)
+
+describe('plural endpoint handler', () => {
+    it('should return 200 when the path does not end with s', async () => {
+        const response = await request(app).get('/book');
+        expect(response.statusCode).toEqual(HttpCode.OK);
+    });
+
+    it('should return 404 when the path ends with s', async () => {
+        const response = await request(app).get('/books');
+        expect(response.statusCode).toEqual(HttpCode.NOT_FOUND);
+        expect(response.body.success).toBe(false);
+        expect(response.body.message).toBe("Not found. Did you mean to use the singular version of the endpoint, /book?");
+    });
+});

backend/helpers/plural.endpoint.handler.ts

@@ -0,0 +1,13 @@
+import { Request, Response } from 'express';
+import { HttpCode, notFoundResponse } from './constants';
+
+export const pluralEndpointHandler = (req: Request, res: Response) => {
+        if (req.path.toLowerCase().endsWith('s')) {
+        return res.status(HttpCode.NOT_FOUND).send({
+            success: false,
+            message: `Not found. Did you mean to use the singular version of the endpoint, ${req.path.substring(0, req.path.length - 1)}?`
+        });
+    }
+
+    return res.status(HttpCode.NOT_FOUND).send(notFoundResponse);
+};

backend/routes/api.ts

@@ -1,13 +1,15 @@
 import { Router } from 'express';;
 
-import { notFoundResponse, HttpCode } from '../helpers/constants';
 import { bookController } from '../controllers/book.api';
 import { chapterController } from '../controllers/chapter.api';
 import { movieController } from '../controllers/movie.api';
 import { characterController } from '../controllers/character.api';
 import { quoteController } from '../controllers/quote.api';
+
 import { errorHandler } from '../middleware/api.errors';
+
 import { passportHelpers } from '../helpers/passport';
+import { pluralEndpointHandler } from '../helpers/plural.endpoint.handler';
 
 const router = Router();
 
@@ -29,8 +31,9 @@ router.route('/character/:id/quote').get([passportHelpers.authenticate, characte
 router.route('/quote').get([passportHelpers.authenticate, quoteController.getQuotes]);
 router.route('/quote/:id').get([passportHelpers.authenticate, quoteController.getQuote]);
 router.route('/quotes/random').get([passportHelpers.authenticate, quoteController.getRandomQuote]);
-router.route('*').get(async (req, res) => {
-	return res.status(HttpCode.NOT_FOUND).send(notFoundResponse);
+
+router.route('*').get((req, res) => {
+	return pluralEndpointHandler(req, res);
 });
 // global error handler. This should always be the last .use
 // and after all routes