Redundant JUnit 5 dependency added to Maven pom.xml after Spring Boot 1 -> 2 migration

[tedyoung]

I ran the org.openrewrite.java.spring.boot2.SpringBoot1To2Migration recipe and it added these two dependencies to the pom.xml file, which isn't needed when using Spring Boot 2.2 (I believe) or later.

		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-api</artifactId>
			<version>5.7.2</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-engine</artifactId>
			<version>5.7.2</version>
			<scope>test</scope>
		</dependency>

Also, there's no need to exclude JUnit 4 from the Spring Boot test-starter, i.e.:

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
			<exclusions>
				<exclusion>
					<groupId>junit</groupId>
					<artifactId>junit</artifactId>
				</exclusion>
			</exclusions>
		</dependency>

isn't necessary, this is enough:

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

[pway99]

Moving this back to the back-log. The unnecessary JUnit 5 dependency is caused by adding both the spring-boot-starter-test and the junit-jupiter-engine dependencies. An approach to this issue would be a new recipe for removing unnecessary dependency tags because they are also transitive.

[timtebeek]

Would it also be possible to add a generic recipe to remove dependency exclusions when no longer transitively part of a dependency?

That could also help clear up the unnecessary junit exclusions, apart from the explicit calls to remove that and the ordering issues that come with it as discussed in https://github.com/openrewrite/rewrite-spring/issues/175#issuecomment-1079311068.

[timtebeek]

There have been quite a few changes to the underlying recipes in the past three years, and I've not had anymore reports about this being an issue. If this remains a problem do please let us know.