Getting started

Decorator-based entity seeding for TypeORM. Annotate entity properties with @Seed(), then create or persist fully populated entity graphs with a single call — including relations, embedded types, and circular guards. Organize complex seeding scenarios into @Seeder classes with declared dependencies that are automatically ordered and executed.

Installation

typeorm and reflect-metadata are peer dependencies.

npm

npm install @joakimbugge/typeorm-seeder typeorm reflect-metadata

yarn

yarn add @joakimbugge/typeorm-seeder typeorm reflect-metadata

pnpm

pnpm add @joakimbugge/typeorm-seeder typeorm reflect-metadata

Verify these compiler options are enabled in your tsconfig.json — TypeORM requires them:

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

Basic usage

Import entity decorators from typeorm, annotate properties with @Seed(), then call create() or save():

import { Entity, PrimaryGeneratedColumn, Column, OneToMany, ManyToOne } from 'typeorm'
import { faker } from '@faker-js/faker'
import { Seed, seed } from '@joakimbugge/typeorm-seeder'

@Entity()
class Author {
  @PrimaryGeneratedColumn()
  id!: number

  @Seed(() => faker.person.fullName())
  @Column()
  name!: string

  @Seed({ count: 3 })
  @OneToMany(() => Book, (b) => b.author)
  books!: Book[]
}

@Entity()
class Book {
  @PrimaryGeneratedColumn()
  id!: number

  @Seed(() => faker.lorem.words(4))
  @Column()
  title!: string

  @Seed()
  @ManyToOne(() => Author, (a) => a.books)
  author!: Author
}

// Build and return directly — no database needed
const author = await seed(Author).create()
// author.name → full name
// author.books → 3 Book instances each with their own seeded properties

// Persist to the database and return
const saved = await seed(Author).save({ dataSource })
// saved.id → assigned by TypeORM after save