Custom plugin: How to test deep configuration of Gradle Project

Help/Discuss
1

I write a custom Gradle plugin. Started working on integration testing and faced the following question:

My plugin applies the following logic, among other things:

repositories.maven(repository -> {
    repository.setName(NAME);
    repository.setUrl(URL);
    repository.mavenContent(MavenRepositoryContentDescriptor::releasesOnly);
});

Then, while testing with Spock:

def "repositories are set up correctly"() {
    given:
    def repositories = project.repositories

    expect:
    repositories.size() == 1
    repositories[0] instanceof MavenArtifactRepository
    def repoReleases = repositories[0] as MavenArtifactRepository
    repoReleases.name == NAME
    repoReleases.url.toString() == URL
    // how to check that this repository is for releases only?
}

How do I prompt the project to show me whether it will use this repository for snapshots or not?

Or is this kind of deep testing not worth the effort?