Using Testcontainers is henceforth allowed, and it is the preferred way to integration-test with third-party software components.
Testcontainers are a self-contained way to run tests against real third-party software products, such as Postgres. Up until now the EDC guideline was to separate test code from infrastructure, but this rule is now relaxed in that integration tests may now use Testcontainers.
However, this does not mean that we should use component tests or integration tests for everything. Or: unit tests are still the preferred way to test software components, they should continue to make up the largest part of our test code base.
- Every test that uses a Testcontainer must be annotated either with
@ComponentTestor another suitable integration test annotation. So when tests are run locally on developers' machines by default only unit tests are executed. - New integration/component tests should use Testcontainers
- Existing component/integration tests are gradually converted over to using Testcontainers