Database Testing with Poku and Sequelize

End-to-end example of testing Poku and the Sequelize 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. A single-connection pool keeps every statement on the same connection, which a temporary table requires. 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 sequelize pg pg-hstore

npm i -D poku tsx @pokujs/docker

Configure the credentials

.env.test:

DB_HOST=localhost
DB_PORT=5432
DB_USER=postgres
DB_PASSWORD=secret
DB_NAME=app

.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 model and connection

db.ts reads every access from process.env:

import { DataTypes, Sequelize } from 'sequelize';

export const sequelize = new Sequelize(
  process.env.DB_NAME!,
  process.env.DB_USER!,
  process.env.DB_PASSWORD!,
  {
    host: process.env.DB_HOST,
    port: Number(process.env.DB_PORT),
    dialect: 'postgres',
    logging: false,
    pool: { min: 1, max: 1 },
  }
);

export const User = sequelize.define(
  'User',
  {
    id: { type: DataTypes.INTEGER, primaryKey: true },
    name: { type: DataTypes.TEXT, allowNull: false },
  },
  { tableName: 'users', timestamps: false }
);

Write the test

users.test.ts:

import { describe, it, assert } from 'poku';
import { User, sequelize } from './db.js';

await describe('Users table', async () => {
  await describe('Seed', async () => {
    await sequelize.query(
      'CREATE TEMP TABLE users (id INT PRIMARY KEY, name TEXT NOT NULL)'
    );
    await User.create({ id: 1, name: 'Poku' });
  });

  await it('reads the created user', async () => {
    const user = await User.findByPk(1);

    assert.strictEqual(
      user?.get('name'),
      'Poku',
      'The created user is returned'
    );
  });

  await sequelize.close();
});

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