Moves Junit 4 support from core to separate module

[froque]

Module is named testcontainers-junit4 (as suggested in #737) instead of junit4 because it fails when building examples with
"> Module version 'org.testcontainers:junit4' is not unique in composite: can be provided by [project :testcontainers-java:docs:examples:junit4, project "

Seems related to gradle/gradle#12872

Fixes #970 and #87 (duplicates #2826, #3101, #3374, #3548, #3737, #3753, #3756, #5287, #5404, #1525)

This is a breaking change and should target future testcontainers-2.0.

Could not find any branch for future 2.0 so this pull request is targeting master.

I started working on a openrewrite recipe to acompany this pull request but is not yet presentable.

[eddumelendez]

Thanks for the PR, @froque ! It has been decided to create a brand new API (JUnit-free) instead of removing junit4 integration from GenericContainer, DockerComposeContainer and Network. The main reason is do not impact those users still using JUnit 4. Introducing the new API, will allow to use it without depending on JUnit 4 and at the same time users can migrate on their own. Once we have it, this PR can be revisited and introduce a junit4 module. In the meantime, I'll close it.

[froque]

@eddumelendez any way to help and speed this up ?

[eldarj]

@eddumelendez Any estimates or ways to speed up the development? Issues such as #970 date back to 2018. It's a bit funny that this junit 4/5 issue is present for years now and we've yet to see any practical outcome.

[nmwael]

Thanks for the PR, @froque ! It has been decided to create a brand new API (JUnit-free) instead of removing junit4 integration from GenericContainer, DockerComposeContainer and Network. The main reason is do not impact those users still using JUnit 4. Introducing the new API, will allow to use it without depending on JUnit 4 and at the same time users can migrate on their own. Once we have it, this PR can be revisited and introduce a junit4 module. In the meantime, I'll close it.

Hi, just ran latest openrewrite recipies
<recipe>org.openrewrite.java.testing.testcontainers.TestContainersBestPractices</recipe> <recipe>org.openrewrite.java.spring.boot3.SpringBoot3BestPractices</recipe>

which ended up giving
cannot access org.junit.rules.TestRule

caused by (GenericContainer<SELF extends GenericContainer)
org.testcontainers.containers

How are the

decoupling going?

regards

[nmwael]

After manually adding the junit 4 dependency, it seems like the issue have disappared after upgrading to a newer version of testcontainers / spring boot test containers.. So I am expecting my issue to be cause by an intermediate upgrade issue. And not reflecting current state