Nested Routes

Part of the Express Basics section of Coddy's Node.js journey. Lesson 17 of 20.

Reviews belong to one recipe, so their URLs live under it: /api/recipes/2/reviews.

const chapters = express.Router({ mergeParams: true });

chapters.get('/', (req, res) => {
    res.json(chaptersOf(req.params.isbn));
});

app.use('/api/books/:isbn/chapters', chapters);

A router's req.params holds only the parameters of its own paths. The :isbn in the mount path belongs to the app, so inside the router it is undefined, unless the router is made with mergeParams: true.

routes/reviews.js is ready, with a reviews object and a hasRecipe(id) helper.

Challenge

Easy

GET /api/recipes/:id/reviews answers that recipe's reviews, [] at first.
POST with { "stars", "text" } adds one and answers 201 with it.
An unknown recipe: 404 with { "error": "No such recipe" }.

Post a review for recipe 1, then send GET /api/recipes/1/reviews and GET /api/recipes/99/reviews.

Try it yourself

import express from 'express';
import { recipes } from '../data.js';

// Reviews by recipe id, like { 1: [{ stars: 5, text: 'Lovely' }] }.
const reviews = {};

const hasRecipe = (id) => recipes.some((recipe) => recipe.id === Number(id));

const router = express.Router();

// GET / lists a recipe's reviews. POST / adds one.

export default router;