Current behaviour with Spring Boot 3.1

When I generate a project from spring initalizr and request that test container support be added I end up with following classpath 

dependencies {
  implementation 'org.springframework.boot:spring-boot-starter'
  testImplementation 'org.springframework.boot:spring-boot-starter-test'
  testImplementation 'org.springframework.boot:spring-boot-testcontainers'
  testImplementation 'org.testcontainers:junit-jupiter'
}

I expected to see something like org.springframework.boot:spring-boot-testcontainers but the presence of org.testcontainers:junit-jupiter is surprising given that junit jupiter is the default for spring boot 3.1, I thought it would automatically be pulled in.

When I examined the dependency tree in my IDE i noticed that org.springframework.boot:spring-boot-testcontainers was pulling in junit 4 which something I don't want in the classpath and the org.springframework.boot:spring-boot-starter-test has exclusions for junit4.

Screenshot 2023-07-20 at 10 01 48 AM

You can find the source code for project where I noticed this behaviour at https://github.com/asaikali/docker-compose-postgres

Suggested Improvements

  1. org.springframework.boot:spring-boot-testcontainers should add org.testcontainers:junit-jupiter as a transitive dependency
  2. org.springframework.boot:spring-boot-testcontainers should exclude junit4 from its transitive dependencies

I believe implementing the above enhancements makes the dependency handling more consistent with the rest of spring boot's handling of test dependencies.

Comment From: wilkinsona

Thanks for the suggestions.

org.springframework.boot:spring-boot-testcontainers should add org.testcontainers:junit-jupiter as a transitive dependency

spring-boot-starter-test is opinionated about the test framework that we use by default but I am not sure that spring-boot-testcontainers should be. Let's see what the rest of the team thinks.

org.springframework.boot:spring-boot-testcontainers should exclude junit4 from its transitive dependencies

We can't do that. See https://github.com/testcontainers/testcontainers-java/issues/6934.

Comment From: mhalbritter

org.springframework.boot:spring-boot-testcontainers should add org.testcontainers:junit-jupiter as a transitive dependency

Say I'm only using "Testcontainers at development time", then I don't need the org.testcontainers:junit-jupiter dependency, right? Making it a dependency of org.springframework.boot:spring-boot-testcontainers would pull it in, even when I don't need it.

Comment From: wilkinsona

We discussed this today and agreed that, for the reasons above, we don't want to make the suggested changes. Thanks anyway.

Comment From: asaikali

Thanks for the explanation folks. This makes sense to me now.