Module decorator and metadata in NestJS - Mini Project: Build & Apply

NestJS Module Decorator and Metadata

📖 Scenario: You are building a simple NestJS application that organizes features into modules. Modules help group related controllers and providers together.

🎯 Goal: Create a NestJS module using the @Module decorator. Add controllers and providers metadata to the module to organize your app structure.

📋 What You'll Learn

Create a module class named AppModule

Use the @Module decorator on AppModule

Add a controller named AppController to the module metadata

Add a provider named AppService to the module metadata

💡 Why This Matters

🌍 Real World

Modules in NestJS help organize code by grouping related controllers and services, making large apps easier to manage.

💼 Career

Understanding module decorators and metadata is essential for building scalable backend applications with NestJS, a popular Node.js framework.

1

Create the AppModule class

Create an empty class named AppModule in your file.

NestJS

# Create an empty class named AppModule
# Your code here

Need a hint?

Use the class keyword followed by AppModule and empty curly braces.

2

Import Module decorator and add it to AppModule

Import Module from @nestjs/common and add the @Module decorator above the AppModule class.

NestJS

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

export class AppModule {}

# Add @Module decorator above AppModule class
# Your code here

Need a hint?

Use @Module({}) just before the class declaration.

3

Add controllers metadata with AppController

Inside the @Module decorator, add a controllers array with AppController as its only element.

NestJS

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

@Module({
  // Add controllers array with AppController
})
export class AppModule {}

# Your code here

Need a hint?

Write controllers: [AppController] inside the decorator object.

4

Add providers metadata with AppService

Add a providers array inside the @Module decorator with AppService as its only element.

NestJS

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

@Module({
  controllers: [AppController],
  // Add providers array with AppService
})
export class AppModule {}

# Your code here

Need a hint?

Add providers: [AppService] inside the decorator object after controllers.