NestJS + Prisma/TypeORM

import { Injectable, OnModuleInit, OnModuleDestroy } from "@nestjs/common";
import { PrismaClient } from "@prisma/client";
 
@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
  async onModuleInit() { await this.$connect(); }
  async onModuleDestroy() { await this.$disconnect(); }
}
 
@Injectable()
export class UsersService {
  constructor(private prisma: PrismaService) {}
  findAll() { return this.prisma.user.findMany(); }
}

// prisma.module.ts
import { Global, Module } from "@nestjs/common";
import { PrismaService } from "./prisma.service.js";
 
@Global()
@Module({
  providers: [PrismaService],
  exports: [PrismaService],
})
export class PrismaModule {}
 
// users.service.ts
import { Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
 
@Injectable()
export class UsersService {
  constructor(private prisma: PrismaService) {}
 
  async findById(id: string) {
    return this.prisma.user.findUnique({ where: { id } });
  }
 
  async create(data: { name: string; email: string }) {
    return this.prisma.user.create({ data });
  }
}
 
// Test override
const mockPrisma = {
  user: {
    findUnique: async () => ({ id: "1", name: "Test", email: "t@t.com" }),
    create: async (args: { data: { name: string; email: string } }) => ({ id: "1", ...args.data }),
  },
};

import { Module } from "@nestjs/common";
import { TypeOrmModule } from "@nestjs/typeorm";
import { User } from "./user.entity.js";
import { UsersService } from "./users.service.js";
 
@Module({
  imports: [TypeOrmModule.forFeature([User])],
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}
 
@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(User) private repo: Repository<User>,
  ) {}
 
  findAll() { return this.repo.find(); }
}

async transfer(fromId: string, toId: string, amount: number) {
  return this.prisma.$transaction(async (tx) => {
    await tx.account.update({ where: { id: fromId }, data: { balance: { decrement: amount } } });
    await tx.account.update({ where: { id: toId }, data: { balance: { increment: amount } } });
  });
}