Feature modules in NestJS - Mini Project: Build & Apply

Building a Feature Module in NestJS

📖 Scenario: You are creating a simple NestJS application to manage books in a library. To keep the code organized, you want to create a feature module dedicated to books.

🎯 Goal: Build a NestJS feature module named BooksModule that includes a service and a controller for managing books.

📋 What You'll Learn

Create a BooksModule class decorated with @Module

Add a BooksService class with a method getBooks() returning a list of book titles

Add a BooksController class with a GET route /books that returns the list of books from BooksService

Import the BooksModule into the root AppModule

💡 Why This Matters

🌍 Real World

Feature modules help organize code in large NestJS applications by grouping related controllers and services.

💼 Career

Understanding feature modules is essential for building scalable and maintainable backend applications with NestJS, a popular Node.js framework.

1

Create the BooksService with a getBooks method

Create a class called BooksService with a method getBooks() that returns an array of strings: ["The Hobbit", "1984", "Clean Code"].

NestJS

// Create the BooksService class with getBooks method
// Your code here

Need a hint?

Use @Injectable() decorator on the service class.

2

Create the BooksController with a GET /books route

Create a class called BooksController decorated with @Controller('books'). Inject BooksService in the constructor. Add a method getAllBooks() decorated with @Get() that returns the result of this.booksService.getBooks().

NestJS

import { Controller, Get } from '@nestjs/common';

// Create the BooksController class with GET /books route
// Your code here

Need a hint?

Use dependency injection in the controller constructor.

3

Create the BooksModule and add service and controller

Create a class called BooksModule decorated with @Module. Add BooksService to the providers array and BooksController to the controllers array.

NestJS

import { Module } from '@nestjs/common';

// Create the BooksModule class with providers and controllers
// Your code here

Need a hint?

Use @Module decorator with providers and controllers arrays.

4

Import BooksModule into AppModule

Modify the existing AppModule class decorated with @Module to import BooksModule in the imports array.

NestJS

import { BooksModule } from './books.module';

// Add BooksModule to imports array in AppModule
// Your code here

Need a hint?

Remember to import BooksModule and add it to the imports array.