[Feature]: JUnit Jupiter extension for reuse of containers

Module

Core

Problem

Assume you have several integration tests splitted in some classes. All this tests can reuse the same container instance. If the container needs some time to setup that would be a great benefit.

Solution

By using the JUnit extension API it would be easy to create a custom annotation like this:

@ContainerConfig(name="containerA", needNewInstance=false) public void testFoo() {}

A container that is needed could be simply defined by a provider:

@ContainerProvider(name="containerA") public GenericContainer<?> createContainerA() {}

By using test lifecycle callbacks (https://junit.org/junit5/docs/current/user-guide/#extensions-lifecycle-callbacks) this could be achieved as a JUnit extension.

I would be happy to help by creating the feature :)

Benefit

Containers that are needed for multiple tests in multiple classes only need to be defined once and the instances can be reused.

Alternatives

Would you like to help contributing this feature?

Yes

Start in the Core module and read the JUnit Jupiter extension API lifecycle callbacks referenced in the issue. Define how the proposed ContainerConfig and ContainerProvider annotations should register and reuse containers across test classes, then verify that shared instances are created once while needNewInstance requests remain isolated.