How-to testcontainers (with PostgreSQL example)

[langovoi]

I searched across Adonis documentation and discussions on Github about using of @testcontainers, but was surprised not find anything.
@testcontainers is a good tool, which allows to have database and not only for tests. For local and same way for CI.

So I figured out how to use it with Adonis and want to share. Guide is focused on PostgreSQL, but sure it can be simply adopted for another testcontainer. And sure it isn't the best way how to use it, so feedback is welcome.

First of all let's create initial point for any testcontainers:

1. create empty file start/testcontainers.ts;
2. add await import('#start/testcontainers') in bin/test.ts before await import('#start/env');

So now we have point where is possible to initialise any testcontainer — start/testcontainers.ts.

For example we need PostgreSQL for our tests:

1. npm i @testcontainers/postgresql --save-dev;
2. populate start/testcontainers.ts with next content:

import { PostgreSqlContainer } from '@testcontainers/postgresql'

const postgresContainer = await new PostgreSqlContainer('postgres:15.6-alpine').start()
// here we inject env for `start/env`, which then be used in `config/database.ts`.
process.env.PG_HOST = postgresContainer.getHost()
process.env.PG_PORT = String(postgresContainer.getPort())
process.env.PG_USER = postgresContainer.getUsername()
process.env.PG_DB_NAME = postgresContainer.getDatabase()
process.env.PG_PASSWORD = postgresContainer.getPassword()

3. in tests/bootstrap.ts in configureSuite add next content:

  suite.onGroup((group) => {
    group.each.setup(() => {
      return testUtils.db().migrate()
    })
  })

Here you can find more testcontainers for Node.js — https://testcontainers.com/modules/?language=nodejs

And if you use Colima, Podman or Rancher take a look to next article: https://node.testcontainers.org/supported-container-runtimes/

[thetutlage]

Looks good. I have never used them, but pinging @RomainLanz as he shared test containers with me some time back.

[RomainLanz]

Yeah, I personally start them inside the test suite or directly in the test file, depending on the needs.

Example here:

import { test } from '@japa/runner'
import { RedisContainer, type StartedRedisContainer } from '@testcontainers/redis'

test.group('Redis Bus', (group) => {
  let container: StartedRedisContainer

  group.setup(async () => {
    container = await new RedisContainer().start()

    return async () => {
      await container.stop()
    }
  })
})

but was surprised not find anything.

Because there is nothing to be done specific to AdonisJS to make it work.

[langovoi]

Because there is nothing to be done specific to AdonisJS to make it work.

I mean there are no guides with examples and best practices, which could be very helpful to start. So I wrote one and published here.

[RomainLanz]

I mean there are no guides with examples and best practices, which could be very helpful to start. So I wrote one and published here.

And thanks for writing that guide. It is great! 🙌🏻

I was just explaining why none was in the documentation already. 😄