UsersService

Kind: Service

Source: atloria-monorepo/apps/parser-orchestrator/test/fixtures/sample-projects/fullstack-nextjs-nestjs/backend/src/users/users.service.ts

UsersService encapsulates user-related backend operations for the NestJS application. It provides methods for retrieving, creating, updating, and deleting users, as well as accessing user relationships such as posts and followers.

Methods

Dependencies

• PrismaService
• EventEmitter2

Where it refuses work

• UsersService stops the work with NotFoundException when !user.
• UsersService stops the work with ConflictException when existingUser — “User with this email already exists”.

Diagram

mermaid
sequenceDiagram
    participant Controller as UsersController
    participant Service as UsersService
    participant Database as Data Layer

    Controller->>Service: findOne(userId)
    Service->>Database: Query user by ID
    Database-->>Service: User record
    Service-->>Controller: User response

    Controller->>Service: getUserPosts(userId)
    Service->>Database: Query user's posts
    Database-->>Service: Posts collection
    Service-->>Controller: Posts response

Usage

ts
import { Injectable } from '@nestjs/common';
import { UsersService } from './users.service';

@Injectable()
export class ProfileService {
  constructor(private readonly usersService: UsersService) {}

  async getProfile(email: string) {
    const user = await this.usersService.findByEmail(email);

    if (!user) {
      return null;
    }

    const [posts, followers] = await Promise.all([
      this.usersService.getUserPosts(user.id),
      this.usersService.getFollowers(user.id),
    ]);

    return {
      user,
      posts,
      followers,
    };
  }
}

AI Coding Instructions

• Keep user persistence and relationship queries inside UsersService; controllers should delegate business operations to the service.
• Use findByEmail() before user creation when email uniqueness must be enforced.
• Ensure findOne() and findByEmail() handle missing users consistently with the application's error-handling conventions.
• Prefer getUserPosts() and getFollowers() over duplicating relation-query logic in other services.
• Validate and sanitize create/update payloads through DTOs before calling create() or update().

Relationships

• DEPENDS_ON → PrismaService
• DEPENDS_ON → eventemitter2

Referenced By

• UsersController (DEPENDS_ON)
• UsersModule (MODULE_PROVIDES)
• UsersModule (MODULE_EXPORTS)