Database Testing with Poku and Drizzle

End-to-end example of testing Poku and Drizzle ORM, from installing the driver to spinning the database up with Docker Compose.

Open the connection in an outer describe, put every assertion inside its own it, and close the connection at the end of that same describe, so cleanup always runs regardless of what an individual assertion does. The container lifecycle lives in a poku.config.js anonymous plugin that uses @pokujs/docker to run setup before the suite and teardown after it, so the suite runs with a plain npm test.

Install

npm i drizzle-orm pg

npm i -D poku tsx @pokujs/docker @types/pg

Configure the credentials

.env.test:

DB_USER=postgres
DB_PASSWORD=secret
DB_PORT=5432
DB_NAME=app
DATABASE_URL="postgresql://${DB_USER}:${DB_PASSWORD}@localhost:${DB_PORT}/${DB_NAME}"

.gitignore:

.env.test

Start the database

docker-compose.yml reads the same .env.test to configure the container:

services:
  postgres:
    image: postgres:18
    environment:
      POSTGRES_USER: ${DB_USER}
      POSTGRES_PASSWORD: ${DB_PASSWORD}
      POSTGRES_DB: ${DB_NAME}
    ports:
      - '${DB_PORT}:5432'
    healthcheck:
      test: ['CMD-SHELL', 'pg_isready -U ${DB_USER} -d ${DB_NAME}']
      interval: 5s
      timeout: 5s
      retries: 10
      start_period: 30s

  db-ready:
    image: busybox
    command: ['tail', '-f', '/dev/null']
    depends_on:
      postgres:
        condition: service_healthy

Define the schema and connection

schema.ts:

import { integer, pgTable, text } from 'drizzle-orm/pg-core';

export const users = pgTable('users', {
  id: integer('id').primaryKey(),
  name: text('name').notNull(),
});

db.ts reads the connection string from process.env. A single Client, not a pool, keeps every statement on the same connection, which a temporary table requires:

import { drizzle } from 'drizzle-orm/node-postgres';
import { Client } from 'pg';

export const client = new Client({
  connectionString: process.env.DATABASE_URL,
});

await client.connect();

export const db = drizzle({ client });

Write the test

users.test.ts:

import { eq, sql } from 'drizzle-orm';
import { describe, it, assert } from 'poku';
import { client, db } from './db.js';
import { users } from './schema.js';

await describe('Users table', async () => {
  await describe('Seed', async () => {
    await db.execute(
      sql`CREATE TEMP TABLE users (id INT PRIMARY KEY, name TEXT NOT NULL)`
    );
    await db.insert(users).values({ id: 1, name: 'Poku' });
  });

  await it('reads the inserted user', async () => {
    const [user] = await db.select().from(users).where(eq(users.id, 1));

    assert.strictEqual(user.name, 'Poku', 'The inserted user is returned');
  });

  await client.end();
});

Configure Poku

poku.config.js:

import { defineConfig } from 'poku';
import { docker } from '@pokujs/docker';

const compose = docker.compose({ envFile: '.env.test' });

export default defineConfig({
  envFile: '.env.test',
  plugins: [
    {
      setup: () => compose.up(),
      teardown: () => compose.down(),
    },
  ],
});

dica

Configuring Poku is optional: you can orchestrate your containers however you prefer and run Poku as poku --envFile='.env.test', for example. In that case, @pokujs/docker is not needed.

Run

Add the test script to package.json:

{
  "scripts": {
    "test": "poku"
  }
}

Then run it:

npm test