About

A library for building a persistence layer with NodeJS

Getting Started

1. Installation

$ npm install @node-ddd/persistence
# OR
$ yarn add @node-ddd/persistence

2. Create a Repository interface for your aggregate

import { Repository } from '@node-ddd/persistence';
import { User } from './User';

export interface UserRepository extends Repository<User> {
  findByEmail(email: string): Promise<User | null>;
}

The Repository interface contains a set of basic methods, but you can add your own methods by extending the interface

3. Create an InMemory implementation

import { InMemoryRepository } from '@node-ddd/persistence';
import { UserRepository } from 'domain';
import { User } from './User';

export class InMemoryUserRepository
  extends InMemoryRepository<User>
  implements UserRepository
{
  constructor(aggregates?: ReadonlyArray<User>) {
    super({ aggregateName: 'User', aggregates });
  }
  findByEmail = (email: string): Promise<User | null> =>
    this.findOneBy(user => user.email === email);
}

4. Create a Typeorm implementation

import { TypeormRepository } from '@node-ddd/persistence';
import { getConnection } from 'typeorm';
import { User, UserRepository } from 'domain';
import { UserEntity } from './UserEntity';

export class TypeormUserRepository
  extends TypeormRepository<User, UserEntity>
  implements UserRepository
{
  constructor() {
    super({
      connection: getConnection(),
      deserializer: user =>
        new User({
          id: toUserId(user.id),
          fullName: user.fullName,
          email: user.email,
        }),
      serializer: user => ({
        id: user.id,
        fullName: user.fullName,
        email: user.email,
      }),
      entity: UserEntity,
    });
  }

  findByEmail = (email: string): Promise<User | null> =>
    this.findFromQuery(() => this.repository.findOne({ email }));
}

Roadmap

• Create a functional programming interface and implementation (with fp-ts)
• Create a prisma implementation