Deprecate JUnit 4 utilities in the project

[artembilan]

Also, migrate JUnit 4 tests to Jupiter.
More info in: spring-projects/spring-framework#34794

[mjd507]

hello, @artembilan , I want to have a try on this.

but we have 42 modules in spring-integration, modifying all of them in one PR may take a long time.
can I do it by aggregating a few modules and raising PR accordingly?

[artembilan]

Thanks for the offer, but not yet. We have to start 7.0 version first.

At the same time I don’t think there are a lot of JUnit 4 tests left to consider this task a huge.
Mostly we need to look into spring-integration-test-support and deprecate those JUnit 4 utils.

If you find any JUnit 4 tests, feel free to issue PR for them even right now. They are just tests, so they don’t affect production artifacts and that does not require a new version cut.

You may also look into migration of this into JUnit Jupiter: https://github.com/spring-projects/spring-integration/blob/main/spring-integration-ip/src/test/java/org/springframework/integration/ip/udp/MulticastRule.java.

There might be more I’m missing right now, but the point is: whatever is in test scope can migrate right now. If it is in main then it has to be deprecated first and only in the next 7.0 version.

[mjd507]

hello, @artembilan
I found very few test classes in spring-integration-core are using junit4 @RunWith(MockitoJUnitRunner.class) ,
e.g. org.springframework.integration.aggregator.MethodInvokingMessageGroupProcessorTests.
this MockitoJUnitRunner is in mockito-core,
however in Jupiter, the replacement MockitoExtension are in mockito-junit-jupiter which we are not included as a test dependency in our build.gradle.

do you think should we include this dependency for few test classes only? or we just replace @Mock object with new actual object.

[artembilan]

do you think should we include this dependency for few test classes only?

I think something like MessageGroup messageGroupMock = mock(); should be enough for us instead of extra dependency just to satisfy some annotation.