Running scripts

A seed script is just a .js or .ts file you execute directly — there is nothing special about it. It can call seed(), runSeeders(), or anything else; the name just means "the file responsible for seeding."

Prefer skipping the script entirely?

The CLI can load and run your seeders directly from the terminal — no seed script needed.

Running seed scripts

When running a seed script directly with Node.js, reflect-metadata must be the very first import — before any entity is loaded. TypeORM's decorators depend on it being in place when the class is evaluated.

import 'reflect-metadata'
import { seed } from '@joakimbugge/typeorm-seeder'
import { User } from './entities/User.js'

await seed(User).save({ dataSource })

TypeScript execution

# ESM
node --no-warnings --loader ts-node/esm src/seed.ts

# CommonJS
npx ts-node src/seed.ts

ts-node is the right tool here — the popular tsx uses esbuild internally which strips decorator metadata, causing TypeORM to fail.

Loading entities from paths

loadEntities resolves a mixed array of entity constructors and glob patterns into a flat array of constructors — the same format TypeORM accepts in its entities DataSource option:

import { loadEntities, seed } from '@joakimbugge/typeorm-seeder'

const classes = await loadEntities([User, 'dist/entities/**/*.js'])
await seed(classes).saveMany(10, { dataSource })

String entries are expanded with glob and each matched file is dynamically imported. Every exported class constructor found in the module is collected. Constructor entries are passed through as-is.

When running with ts-node, you can point directly at source files:

const classes = await loadEntities(['src/entities/**/*.ts'])

Loading seeders from paths

loadSeeders works the same way as loadEntities but collects only constructors decorated with @Seeder. Non-seeder exports in matched files are ignored.

import { loadSeeders, runSeeders } from '@joakimbugge/typeorm-seeder'

const seeders = await loadSeeders(['dist/seeders/**/*.js'])
await runSeeders(seeders, { dataSource })

Constructor entries are passed through as-is, so you can mix explicit references with glob patterns:

const seeders = await loadSeeders([UserSeeder, 'dist/seeders/Post*.js'])
await runSeeders(seeders, { dataSource })

When running with ts-node, you can point directly at source files:

const seeders = await loadSeeders(['src/seeders/**/*.ts'])