Set Up Prisma Database Seeding

// package.json
{
  "prisma": {
    "seed": "npx tsx prisma/seed.ts"
  }
}

// prisma/seed.ts
import { PrismaClient, Role } from '@prisma/client';

const prisma = new PrismaClient();

async function main() {
  console.log('Seeding database...');

  // Seed roles / reference data (idempotent with upsert)
  const admin = await prisma.user.upsert({
    where: { email: 'admin@example.com' },
    update: {},
    create: {
      email: 'admin@example.com',
      name: 'Admin User',
      role: Role.ADMIN,
      password: await hashPassword('admin123'),
    },
  });

  const user = await prisma.user.upsert({
    where: { email: 'user@example.com' },
    update: {},
    create: {
      email: 'user@example.com',
      name: 'Regular User',
      role: Role.USER,
      password: await hashPassword('user123'),
    },
  });

  // Seed sample posts
  const posts = [
    { title: 'Getting Started with Prisma', slug: 'getting-started-prisma', published: true },
    { title: 'Advanced Query Patterns', slug: 'advanced-queries', published: true },
    { title: 'Draft Post', slug: 'draft-post', published: false },
  ];

  for (const post of posts) {
    await prisma.post.upsert({
      where: { slug: post.slug },
      update: {},
      create: {
        ...post,
        content: `Content for ${post.title}. This is seeded data.`,
        authorId: admin.id,
      },
    });
  }

  console.log('Seeding complete.');
}

main()
  .then(() => prisma.$disconnect())
  .catch((e) => {
    console.error('Seeding failed:', e);
    prisma.$disconnect();
    process.exit(1);
  });

// prisma/factories.ts
import { PrismaClient, Prisma } from '@prisma/client';

export function createUserFactory(overrides: Partial<Prisma.UserCreateInput> = {}) {
  const id = Math.random().toString(36).slice(2);
  return {
    email: `user-${id}@test.com`,
    name: `Test User ${id}`,
    role: 'USER' as const,
    ...overrides,
  };
}

export function createPostFactory(
  authorId: string,
  overrides: Partial<Prisma.PostCreateInput> = {}
) {
  const id = Math.random().toString(36).slice(2);
  return {
    title: `Test Post ${id}`,
    content: `This is test content for post ${id}`,
    slug: `test-post-${id}`,
    published: true,
    author: { connect: { id: authorId } },
    ...overrides,
  };
}

# Run seed manually
npx prisma db seed

# Seed runs automatically after:
npx prisma migrate dev
npx prisma migrate reset