[PROPOSAL] migrate to JUnit 5

[rursprung]

What/Why

What are you proposing?

the project should (eventually) migrate to JUnit 5 so that the newer features & patterns can be used and so that it isn't stuck on an old major release of JUnit.

What users have asked for this feature?

n/a

What problems are you trying to solve?

avoid getting stuck on an old library.

What is the developer experience going to be?

• no changes for users of opensearch-java
• more modern experience for developers of opensearch-java

Are there any security considerations?

no

Are there any breaking changes to the API

no (only affects the tests)

What is the user experience going to be?

n/a

Are there breaking changes to the User Experience?

no

Why should it be built? Any reason not to?

long-term stability by being on the current major release of the testing library and improved developer experience

What will it take to execute?

manual effort to migrate it (maybe part of it can be automated?).

Any remaining open questions?

n/a

[reta]

@rursprung we use the OpenSearch -> Apache Lucene -> Carrotsearch (https://labs.carrotsearch.com/randomizedtesting.html) scaffolding, in theory we could use JUnit 4 and JUnit 5 together (would be messy), but without updating the whole chain of dependencies, it would not be possible to use JUnit 5 only.

[rursprung]

hm, xkcd at work, huh?

thanks for your insights!

it feels like that library is dead in the water, nearly nothing happening and the issue for JUnit 5 has been open since 2018: randomizedtesting/randomizedtesting#256

i also saw a related ticket in the OpenSearch repo: opensearch-project/sql#1974 (sadly that one is proposing to kick out JUnit 5 tests and revert them back to JUnit 4 😞)