JUnit5 support

[kennknowles]

Imported from Jira BEAM-3415. Original Jira may contain additional context.
Reported by: romain.manni-bucau.

[IraRe]

We're looking forward to this feature for some time already. Are there any updates on the topic?

[kennknowles]

Can you share more about how you want to use it? I think the Beam testing utilities include some JUnit4 utilities (like TestPipeline, and then also some hamcrest matchers. Maybe it would make sense to build a separate JUnit5 version of these while keeping the JUnit4 versions for compatibility with existing uses?

[the-serious-programmer]

Just starting out with testing my apache beam pipeline. Must say I am pretty surprised this is still depending on Junit 4.
Junit 5 has been out for a while now and Junit 4 is outdated.

[younes-d]

Is anyone actively working on adding JUnit5 support to Beam?

In TestPipeline,

import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;

are deprecated in JUnit5