TS Seed Script: Drizzle ORM + Zod + Faker (Minimal)

seed_drizzle_zod_faker.ts

// tsx seed.ts

import { faker } from '@faker-js/faker';
import { pgTable, text, varchar, timestamp } from 'drizzle-orm/pg-core';
import { drizzle, PostgresJsDatabase } from 'drizzle-orm/postgres-js';
import { createInsertSchema } from 'drizzle-zod';
import { customAlphabet } from 'nanoid';
import postgres from 'postgres';
import { z } from 'zod';

import '#env.ts';

const alphabet = '0123456789abcdefghijklmnopqrstuvwxyz';
const length = 14;

const nanoid = customAlphabet(alphabet, length);

function generatePublicId() {
  return nanoid();
}

const queryClient = postgres(process.env.DATABASE_DIRECT_URL || '');

const db: PostgresJsDatabase = drizzle(queryClient, {
  logger: true,
});

const users = pgTable('users', {
  id: varchar('id', { length: 14 }).primaryKey(),
  name: text('name').notNull(),
  email: text('email').notNull().unique(),
  createdAt: timestamp('created_at').notNull().defaultNow(),
  updatedAt: timestamp('updated_at').notNull().defaultNow(),
});

const insertUserSchema = createInsertSchema(users, {
  email: (schema) => schema.email.email('Email address is not valid'),
});

type UserToBeInserted = z.infer<typeof insertUserSchema>;

const generateUserRows = (count: number): UserToBeInserted[] => {
  const rows: UserToBeInserted[] = [];

  for (let i = 0; i < count; i++) {
    rows.push({
      id: generatePublicId(),
      email: faker.internet.email(),
      name: `${faker.person.firstName()} ${faker.person.lastName()}`,
    });
  }

  return rows;
};

async function seed() {
  console.log('Seeding...');
  console.time('DB has been seeded!');

  // database teardown
  await db.delete(users);

  // database setup
  const newUserRows = generateUserRows(100);
  await db.insert(users).values(newUserRows).returning();
}

seed()
  .catch((e) => {
    console.error(e);
    process.exit(1);
  })
  .finally(async () => {
    console.log('Seeding done!');
    process.exit(0);
  });