Seeders

Seeders provide an application-layer CLI for populating your database outside of tests. They use dependency injection, giving them access to your services, repositories, and any other provider in your module tree.

Seeders are part of the core stratal package and run as built-in Quarry CLI commands.

Tip

For seeders used inside tests with TestingModule, see Testing Seeders.

Creating a seeder

Extend the Seeder base class from stratal/seeder and implement the run() method. Use constructor injection to access your services:

import { Seeder } from 'stratal/seeder'
import { inject, Transient } from 'stratal/di'
import { NotesService } from '../notes/notes.service'

@Transient()
export class NotesSeeder extends Seeder {
  constructor(@inject(NotesService) private readonly notesService: NotesService) {
    super()
  }

  async run(): Promise<void> {
    const notes = [
      { title: 'Welcome', content: 'This note was created by a seeder' },
      { title: 'Getting Started', content: 'Seeders populate your app with initial data' },
      { title: 'Stratal', content: 'A modular Cloudflare Workers framework' },
    ]

    for (const note of notes) {
      this.notesService.create(note)
    }
  }
}

Note

Mark seeders with @Transient() so a fresh instance is created each time the seeder runs.

Registering seeders

Add the seeder to a module’s providers array:

import { Module } from 'stratal/module'
import { NotesSeeder } from './seeders/notes.seeder'

@Module({
  providers: [NotesSeeder],
})
export class NotesModule {}

CLI usage

Seeders run via the Quarry CLI using the built-in db:seed and db:seed:list commands.

Note

Quarry is Stratal’s CLI framework. See the Quarry CLI page for the full command reference.

Run a specific seeder

Pass the seeder class name to db:seed:

npx quarry db:seed NotesSeeder

Run all seeders

npx quarry db:seed --all

List available seeders

npx quarry db:seed:list

Dry run

Preview which seeders would run without executing them:

npx quarry db:seed --all --dry-run

Naming convention

Seeders are identified by their class name when using the db:seed command:

Class name	CLI usage
NotesSeeder	npx quarry db:seed NotesSeeder
RolePermissionsSeeder	npx quarry db:seed RolePermissionsSeeder
InitialDataSeeder	npx quarry db:seed InitialDataSeeder

Calling other seeders

Use this.call() to invoke another seeder from within a seeder:

import { Seeder } from 'stratal/seeder'
import { Transient } from 'stratal/di'
import { UserSeeder } from './user.seeder'
import { PostSeeder } from './post.seeder'

@Transient()
export class DatabaseSeeder extends Seeder {
  async run(): Promise<void> {
    await this.call(UserSeeder)
    await this.call(PostSeeder)
  }
}

Auto-discovery

Seeders are automatically discovered from the module tree. Any class that extends Seeder and is listed in a module’s providers array will be found by the CLI. Only bare class providers are scanned — value, factory, and existing providers are skipped.

How it works

The Quarry CLI uses Wrangler’s getPlatformProxy() to obtain your Cloudflare bindings (D1, KV, R2, etc.) locally. It then bootstraps your module tree, discovers all classes that extend Seeder, and executes their run() methods inside a request scope.

Using with factories

Seeders pair naturally with factories for generating realistic data:

import { Seeder } from 'stratal/seeder'
import { inject, DI_TOKENS, Transient } from 'stratal/di'
import type { DatabaseService } from '@stratal/framework/database'
import { UserFactory } from './user.factory'
import { PostFactory } from './post.factory'

@Transient()
export class DemoDataSeeder extends Seeder {
  constructor(
    @inject(DI_TOKENS.Database) private readonly db: DatabaseService,
  ) {
    super()
  }

  async run(): Promise<void> {
    const users = await new UserFactory().count(5).createManyAndReturn(this.db)

    for (const user of users) {
      await new PostFactory()
        .state(attrs => ({ ...attrs, authorId: user.id }))
        .count(3)
        .createMany(this.db)
    }
  }
}

Next steps

• Quarry CLI for the full command framework reference.
• Testing Seeders for seeders used inside tests with TestingModule.
• Factories for generating test data with Faker.js.
• Database for configuring the database connection.