La aplicación debería quedar organizada así:

Donde los módulos deberían quedar asi:

// src/products/products.module.ts
import { Module } from '@nestjs/common';

import { ProductsController } from './controllers/products.controller';
import { BrandsController } from './controllers/brands.controller';
import { CategoriesController } from './controllers/categories.controller';
import { ProductsService } from './services/products.service';
import { BrandsService } from './services/brands.service';
import { CategoriesService } from './services/categories.service';

@Module({
  controllers: [ProductsController, CategoriesController, BrandsController],
  providers: [ProductsService, BrandsService, CategoriesService],
  exports: [ProductsService],
})
export class ProductsModule {}

// src/users/users.module.ts
import { Module } from '@nestjs/common';

import { CustomerController } from './controllers/customers.controller';
import { CustomersService } from './services/customers.service';
import { UsersController } from './controllers/users.controller';
import { UsersService } from './services/users.service';

import { ProductsModule } from '../products/products.module';

@Module({
  imports: [ProductsModule],
  controllers: [CustomerController, UsersController],
  providers: [CustomersService, UsersService],
})
export class UsersModule {}

// src/app.module.ts
import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { UsersModule } from './users/users.module';
import { ProductsModule } from './products/products.module';

@Module({
  imports: [UsersModule, ProductsModule],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

Curso de NestJS: Programación Modular

Nicolas Molina

Encapsular lógica en módulos3/17