TypeORM Seeding

A delightful way to seed test data into your database.
Inspired by the awesome framework laravel in PHP and of the repositories from pleerock
_{Made with ❤️ by Gery Hirschfeld and contributors}

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❯ Table of content

• Introduction
• Installation
• Basic Seeder
• Factory API
• Changelog
• License

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❯ Introduction

Isn't it exhausting to create some sample data for your database, well this time is over!

How does it work? Just create a factory for your entities (models) and a seed script.

Enity

First create your TypeORM entites.

// user.enity.ts
@Entity()
export class User {
  @PrimaryGeneratedColumn('uuid') id: string
  @Column({ nullable: true }) name: string
  @Column({ type: 'varchar', length: 100, nullable: false }) password: string
  @OneToMany((type) => Pet, (pet) => pet.user) pets: Pet[]

  @BeforeInsert()
  async setPassword(password: string) {
    const salt = await bcrypt.genSalt()
    this.password = await bcrypt.hash(password || this.password, salt)
  }
}

// pet.enity.ts
@Entity()
export class Pet {
  @PrimaryGeneratedColumn('uuid') id: string
  @Column() name: string
  @Column() age: number
  @ManyToOne((type) => User, (user) => user.pets)
  @JoinColumn({ name: 'user_id' })
  user: User
}

Factory

The purpose of a factory is to create new fake entites with generate data.

Factories can also be used to generate test data for some unit, integration or e2e tests.

// user.factory.ts
define(User, (faker: typeof Faker) => {
  const gender = faker.random.number(1)
  const firstName = faker.name.firstName(gender)
  const lastName = faker.name.lastName(gender)

  const user = new User()
  user.name = `${firstName} ${lastName}`
  user.password = faker.random.word()
  return user
})

// pet.factory.ts
define(Pet, (faker: typeof Faker) => {
  const gender = faker.random.number(1)
  const name = faker.name.firstName(gender)

  const pet = new Pet()
  pet.name = name
  pet.age = faker.random.number()
  pet.user = factory(User)() as any
  return pet
})

Seeder

The seeder can be called by the configured cli command seed:run. In this case it generates 10 pets with a owner (User).

// create-pets.seed.ts
export default class CreatePets implements Seeder {
  public async run(factory: Factory, connection: Connection): Promise<any> {
    await factory(Pet)().seedMany(10)
  }
}

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❯ Installation

Before using this TypeORM extension please read the TypeORM Getting Started documentation. This explains how to setup a TypeORM project.

You can install our extension with npm or yarn.

npm i typeorm-seeding
# or
yarn add typeorm-seeding

Optional, for Faker types

npm install -D @types/faker

Configuration

To configure the path to your seeds and factories change the TypeORM config file(ormconfig.js or ormconfig.json).

Default is src/database/{seeds,factories}/**/*{.ts,.js}

ormconfig.js

module.exports = {
  ...
  seeds: ['src/seeds/**/*{.ts,.js}'],
  factories: ['src/factories/**/*{.ts,.js}'],
}

.env

TYPEORM_SEEDING_FACTORIES=src/factories/**/*{.ts,.js}
TYPEORM_SEEDING_SEEDS=src/seeds/**/*{.ts,.js}

CLI Configuration

Add the following scripts to your package.json file.

"scripts": {
  "seed:config": "ts-node ./node_modules/typeorm-seeding/dist/cli.js config"
  "seed:run": "ts-node ./node_modules/typeorm-seeding/dist/cli.js seed"
  ...
}

Now you are able to execute your seeds with this command npm run seed:run.

Add the following TypeORM cli commands to the package.json to drop and sync the database.

"scripts": {
  ...
  "schema:drop": "ts-node ./node_modules/typeorm/cli.js schema:drop",
  "schema:sync": "ts-node ./node_modules/typeorm/cli.js schema:sync",
  ...
}

CLI Options

Option	Default	Description
--seed or -s	null	Option to specify a specific seeder class to run individually.
--connection or -c	null	Name of the typeorm connection. Required if there are multiple connections.
--configName or -n	ormconfig.js	Name to the typeorm config file.
--root or -r	process.cwd()	Path to the typeorm config file.

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❯ Basic Seeder

The seeds files define how much and how the data are connected with each other. The files will be executed alphabetically.

import { Factory, Seeder } from 'typeorm-seeding'
import { Connection } from 'typeorm'
import { User } from '../entities'

export default class CreateUsers implements Seeder {
  public async run(factory: Factory, connection: Connection): Promise<any> {
    await connection
      .createQueryBuilder()
      .insert()
      .into(User)
      .values([
        { firstName: 'Timber', lastName: 'Saw' },
        { firstName: 'Phantom', lastName: 'Lancer' },
      ])
      .execute()
  }
}

❯ Factory API

For all entities we want to seed, we need to define a factory. To do so we give you the awesome faker library as a parameter into your factory. Then create your "fake" entity and return it. Those factory files should be in the src/database/factories folder and suffixed with .factory like src/database/factories/user.factory.ts.

Types	Description
Enity	TypeORM Enity like the user or the pet in the samples.
Context	Argument to pass some static data into the factory function.
EntityFactory	This object is used to make new filled entities or seed it into the database.

define

The define function creates a new enity factory.

define: <Entity, Context>(entity: Entity, factoryFn: FactoryFunction<Entity, Context>) => void;

import Faker from 'faker'
import { define } from 'typeorm-seeding'
import { User } from '../entities'

define(User, (faker: typeof Faker, context: { roles: string[] }) => { ... })

factory

Factory retrieves the defined factory function and returns the EntityFactory to start creating new enities.

factory: (entity: Entity) => (context?: Context) => EntityFactory<Entity, Context>

factory(Pet)()
factory(Pet)({ name: 'Balou' })

EntityFactory

map

Use the .map() function to alter the generated value before they get persisted.

map(mapFunction: (entity: Entity) => Promise<Entity>): EntityFactory<Entity, Context>

await factory(User)()
  .map(async (user: User) => {
    const pets: Pet[] = await factory(Pet)().seedMany(2)
    const petIds = pets.map((pet: Pet) => pet.Id)
    await user.pets().attach(petIds)
  })
  .seedMany(5)

make & makeMany

Make and makeMany executes the factory functions and return a new instance of the given enity. The instance is filled with the generated values from the factory function.

overrideParams - Override some of the attributes of the enity.

make(overrideParams: EntityProperty<Entity> = {}): Promise<Entity>

await factory(User)().make()
await factory(User)().makeMany(10)

// override the email
await factory(User)().make({ email: 'other@mail.com' })
await factory(User)().makeMany(10, { email: 'other@mail.com' })

seed & seedMany

seed and seedMany is similar to the make and makeMany method, but at the end the created entity instance gets persisted in the database.

overrideParams - Override some of the attributes of the enity.

seed(overrideParams: EntityProperty<Entity> = {}): Promise<Entity>

await factory(User)().seed()
await factory(User)().seedMany(10)

// override the email
await factory(User)().seed({ email: 'other@mail.com' })
await factory(User)().seedMany(10, { email: 'other@mail.com' })

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❯ Changelog

Changelog

❯ License

MIT