Module re-exporting in NestJS - Mini Project: Build & Apply

NestJS Module Re-exporting

📖 Scenario: You are building a NestJS application that has two feature modules: UsersModule and AuthModule. You want to create a SharedModule that re-exports these two modules so other parts of the app can import just the SharedModule to get access to both.

🎯 Goal: Build a SharedModule that imports and re-exports UsersModule and AuthModule so other modules can use their providers by importing only SharedModule.

📋 What You'll Learn

Create a UsersModule with a simple provider

Create an AuthModule with a simple provider

Create a SharedModule that imports and re-exports UsersModule and AuthModule

Use NestJS module syntax with @Module decorator and imports and exports arrays

💡 Why This Matters

🌍 Real World

In real NestJS apps, re-exporting modules via a SharedModule helps keep imports clean and organized. It lets you group related modules and share their providers easily.

💼 Career

Understanding module re-exporting is important for building scalable NestJS applications and working in teams where modular architecture is required.

1

Create UsersModule with a provider

Create a NestJS module called UsersModule that provides a class called UsersService. Use the @Module decorator with a providers array containing UsersService.

NestJS

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

// Your code here

Need a hint?

Remember to export UsersService and include it in both providers and exports arrays so it can be used outside the module.

2

Create AuthModule with a provider

Create a NestJS module called AuthModule that provides a class called AuthService. Use the @Module decorator with a providers array containing AuthService and export AuthService as well.

NestJS

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

export class UsersService {}

@Module({
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}

// Your code here

Need a hint?

Follow the same pattern as UsersModule but for AuthService and AuthModule.

3

Create SharedModule importing UsersModule and AuthModule

Create a NestJS module called SharedModule that imports UsersModule and AuthModule. Use the @Module decorator with an imports array containing UsersModule and AuthModule.

NestJS

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

export class UsersService {}

@Module({
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}

export class AuthService {}

@Module({
  providers: [AuthService],
  exports: [AuthService],
})
export class AuthModule {}

// Your code here

Need a hint?

Use both imports and exports arrays in @Module to re-export the imported modules.

4

Use SharedModule in another module

Create a NestJS module called AppModule that imports only the SharedModule. Use the @Module decorator with an imports array containing SharedModule.

NestJS

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

export class UsersService {}

@Module({
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}

export class AuthService {}

@Module({
  providers: [AuthService],
  exports: [AuthService],
})
export class AuthModule {}

@Module({
  imports: [UsersModule, AuthModule],
  exports: [UsersModule, AuthModule],
})
export class SharedModule {}

// Your code here

Need a hint?

This shows how other modules can import SharedModule to get access to UsersModule and AuthModule providers.