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Data Factories

Available in: Business, Enterprise tiers

Type-safe builders for realistic mock data with optional Prisma persistence.

Why Use Data Factories​

Problem: Creating test data is tedious:

  • Manually writing test data for every test
  • Data doesn't match real schema structure
  • Hard to create valid related data
  • No easy way to persist to database

Solution: Generate factories that build type-safe test data with realistic values.

Benefits​

  • Type-Safe: Follows your Prisma schema exactly
  • Realistic Data: Sensible defaults for all fields
  • Relationships: Handle nested data easily
  • Optional Persistence: Build in-memory or save to database

Prerequisites​

# Core dependencies
pnpm add @prisma/client

# PZG Pro license required

Generate​

Add to your schema.prisma:

generator pzgPro {
  provider = "node ./node_modules/prisma-zod-generator/lib/cli/pzg-pro.js"
  output = "./generated/pro"
  enableFactories = true
}

Then run:

prisma generate

Generated Files​

generated/
  pro/
    factories/
      factories.ts         # Factory builder per model + factory registry
      seeders.ts           # Database seeders
      providers.ts         # Fake-data providers
      fixtures/            # Static fixtures, one file per model
        user.ts
        post.ts
        index.ts
      test-helpers.ts      # Test setup/teardown helpers
      utils.ts             # Shared factory utilities
      types.ts             # TypeScript types
      USAGE.md             # Practical usage guide
      README.md            # Reference documentation

factories.ts, fixtures/, and seeders.ts are each gated behind an option (generateFactories, generateFixtures, generateSeeders). The rest is always emitted.

Basic Usage​

import { userFactory, postFactory } from '@/generated/pro/factories/factories'

// Build in-memory (no database)
const user = userFactory.build({
  email: 'test@example.com'
})

// Build many
const users = userFactory.buildMany(10)

// With custom values
const admin = userFactory.build({
  email: 'admin@example.com',
  role: 'ADMIN'
})

Typing​

Each model gets a <Model>Shape interface derived from your schema, and the factory is Factory<<Model>Shape> — so build() returns that shape and a typo in an override is a compile error. Before 2.6.0 every factory was Factory<any> with Partial<any> overrides, which meant nothing about a build() call was checked despite the "follows your Prisma schema exactly" promise.

Persistence (Optional)​

Hand the factory a Prisma client first. Without it, create() and createMany() throw and tell you to call setPrismaClient() — use build()/buildMany() when you only want objects. (Before 2.4.1 they warned and returned unsaved objects with a placeholder id, so a seeder could appear to succeed while writing nothing.)

import { PrismaClient } from '@prisma/client';

const prisma = new PrismaClient();
userFactory.setPrismaClient(prisma); // required for create()/createMany()
// Create in database
const user = await userFactory.create({
  email: 'db@example.com'
})

// Create many
const users = await userFactory.createMany(5)

// With relationships
const userWithPosts = await userFactory.create({
  posts: {
    create: [
      postFactory.build({ title: 'First Post' }),
      postFactory.build({ title: 'Second Post' })
    ]
  }
})

Testing Example​

import { describe, it, expect } from 'vitest'
import { userFactory } from '@/generated/pro/factories/factories'

describe('User API', () => {
  it('creates a user', async () => {
    const userData = userFactory.build()
    
    const response = await fetch('/api/users', {
      method: 'POST',
      body: JSON.stringify(userData)
    })
    
    expect(response.ok).toBe(true)
  })
})

See Also​