This is a sample project that shows how to use Testcontainers for (integration) tests in combination with ZIO.
Testcontainers provides a way to run a Docker container with e.g. a database for testing. It is also possible to run a docker-compose for testing.
If the Docker container exposes a port, it will map this exposed port to a free port number on the external host, avoiding port conflicts. In your test you can retrieve the mapping port number so you can connect to the Docker container(s).
The sample project is a simple REST API for to do items with a create, delete, get, and get all endpoint.
Besides that, it contains the example AerospikeContainer on how to use
Testcontainers' GenericContainer for when there is
no container available in the Testcontainers project.
The TodoRepository is responsible for storing the to do's in the database.
TodoRepositoryTest contains the tests for the repository. There are different Specs
that use TodoRepositoryTest, each injecting different layers for the database:
| Spec | Description |
|---|---|
TodoRepositoryMySqlLayerSharedSpec |
uses a shared MySQL Docker container for the tests |
TodoRepositoryMySqlLayerNonSharedSpec |
uses a non-shared MySQL Docker container for the test, this means that for every test a new Docker container is started |
TodoRepositoryH2Spec |
uses a H2 database instead of a Docker container, which is faster, but only an emulation of MySQL |
MysqlDockerContainer shows how to start a MySQL docker container and
obtain the correct jdbc connection url, username, and password to connect to the MySQL instance.
TestDatabase contains two test layers: one for MySQL and one for H2, to be able
to switch easily between the two test databases.
The TodoService is a lightweight service that doesn't do a lot, it is added to
show how to test such a service that depends on a repository that depends on a database
without requiring a database. This is done in TodoServiceSpec using ZIO mock.
The TodoApi defines the routes for the REST API and TodoApp is the application.
The integration test isn't very extensive, it is meant to show how to test the entire application using a docker compose.
The command sbt integrationTest will build a Docker container of the application
and will run the test(s) in the integration-test project.
TodoAppSpec tests the application. DockerCompose starts the docker compose file, which
contains the application and the database. It retrieves the mapped host and port and
composes the URL for the application so we can use a HTTP client to connect
the application's REST end points.