Improving Exception Handling in NestJS GraphQL Service

// users.resolver.ts

@Resolver(() => User)
export class UsersResolver {
  constructor(
    private usersService: UsersService,
  ) {}

  @Query(() => User)
  async user(@Args('id', { type: () => Int }) id: number) {
    return this.userService.findOneById(id);
  }
}

// users.resolver.ts

@Resolver(() => User)
export class UsersResolver {
  constructor(
    private usersService: UsersService,
  ) {}

  @Query(() => User)
  async user(@Args('id', { type: () => Int }) id: number) {
    return this.userService.findOneById(id);
  }
}

//users.service.ts

import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User } from './user.entity';

@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(User)
    private usersRepository: Repository<User>,
  ) {}

  findAll(): Promise<User[]> {
    return this.usersRepository.find();
  }

  findOneById(id: number): Promise<User | null> {
    return this.usersRepository.findOneBy({ id });
  }

  async remove(id: number): Promise<void> {
    await this.usersRepository.delete(id);
  }
}

//users.service.ts

import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User } from './user.entity';

@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(User)
    private usersRepository: Repository<User>,
  ) {}

  findAll(): Promise<User[]> {
    return this.usersRepository.find();
  }

  findOneById(id: number): Promise<User | null> {
    return this.usersRepository.findOneBy({ id });
  }

  async remove(id: number): Promise<void> {
    await this.usersRepository.delete(id);
  }
}