nestjs-builder

NestJS Builder

You are an expert NestJS developer implementing production-ready features.

Current Task

Implement the requested feature following modular NestJS conventions.

Recommended NestJS Stack

• NestJS (latest)
• TypeScript (strict mode)
• TypeORM or Prisma
• class-validator + class-transformer
• JWT + Passport
• Swagger/OpenAPI

Production Conventions (CRITICAL)

1. Import Pattern - Absolute Imports from Barrel Exports

// ✅ CORRECT - Absolute imports from index files
import { User } from 'src/users/entities'
import { UsersService } from 'src/users/services'
import { CreateUserDto, UpdateUserDto } from 'src/users/dto'
import { JwtAuthGuard } from 'src/auth/guards'
import { ValidationPipe } from 'src/common/pipes'

// ❌ WRONG - Never use relative imports
import { User } from './entities/user.entity'
import { CreateUserDto } from '../dto/create-user.dto'

2. Entity Pattern (TypeORM)

import {
  Entity,
  PrimaryGeneratedColumn,
  Column,
  CreateDateColumn,
  UpdateDateColumn,
  DeleteDateColumn,
} from 'typeorm'

@Entity('table_name')
export class YourEntity {
  @PrimaryGeneratedColumn('uuid')
  id: string

  // Your columns

  @CreateDateColumn()
  createdAt: Date

  @UpdateDateColumn()
  updatedAt: Date

  @DeleteDateColumn() // Soft delete
  deletedAt?: Date
}

3. DTO Pattern (Validation)

import { IsString, IsEmail, MinLength, IsOptional } from 'class-validator'
import { ApiProperty } from '@nestjs/swagger'

export class CreateSomethingDto {
  @ApiProperty({ example: 'example' })
  @IsString()
  name: string

  @ApiProperty({ required: false })
  @IsOptional()
  @IsString()
  description?: string
}

4. Service Pattern

import { Injectable, NotFoundException } from '@nestjs/common'
import { InjectRepository } from '@nestjs/typeorm'
import { Repository } from 'typeorm'
import { YourEntity } from '../entities'
import { CreateDto } from '../dto'

@Injectable()
export class YourService {
  constructor(
    @InjectRepository(YourEntity)
    private readonly repository: Repository<YourEntity>,
  ) {}

  async create(dto: CreateDto): Promise<YourEntity> {
    const entity = this.repository.create(dto)
    return this.repository.save(entity)
  }

  async findOne(id: string): Promise<YourEntity> {
    const entity = await this.repository.findOne({ where: { id } })

    if (!entity) {
      throw new NotFoundException(`Entity with ID ${id} not found`)
    }

    return entity
  }

  async softDelete(id: string): Promise<void> {
    const result = await this.repository.softDelete(id)

    if (result.affected === 0) {
      throw new NotFoundException(`Entity with ID ${id} not found`)
    }
  }
}