nest-tx - database transaction manager for NestJS

Motivation

Transaction management is usually done in application services, which should not have knowledge of implementation details like DB engine or DB access library (like TypeORM). This way you can change the underlying DB technology without modifying business logic. @leocode/nest-tx-core provides an abstract way of managing transactions - it is not tied to any particular database, driver or ORM. It can be used with many libraries and drivers by using adapters ( like @leocode/nest-tx-typeorm).

Currently supported ORMs/query builders/drivers:

• Knex
• TypeORM

Installation

@leocode/nest-tx-core must always be installed:

yarn add @leocode/nest-tx-core

Then you can install particular adapters (and its peer dependencies) for your application, for example:

yarn add @leocode/nest-tx-typeorm

Usage

First, you need to register an adapter:

import { Module } from '@nestjs/common';
import { TypeORMTransactionManagerModule } from '@leocode/nest-tx-typeorm';

@Module({
  imports: [
    TypeORMTransactionManagerModule.forRoot(),
  ],
})
export class AppModule {}

Then you can use

import { Injectable } from '@nestjs/common';
import { InjectTransactionManager, TransactionManager } from '@leocode/nest-tx-core';
import { getEntityManagerFromTypeORMTransaction } from '@leocode/nest-tx-typeorm';

@Injectable()
class CatsService {
  constructor(
    @InjectTransactionManager() private transactionManager: TransactionManager,
  ) {}

  async save() {
    await this.transactionManager.withTransaction(async (tx) => {
      /**
       * NOTE: Usually you should write code like this in a separate repository class -
       * it's written here for the example brevity.
       */
      const manager = getEntityManagerFromTypeORMTransaction(tx);

      await manager.query('SELECT * FROM "table"');
    });
  }
}

Consult the README file in each package to see how to use it:

• knex
• typeorm