We have covered some test cases in our nightly run and we'd like to backport those test cases to the community code branch. This work includes the efforts but not limited to:
- Add more meaningful test cases for existing code so it's hard to break it as stability and compatibility should always be guarded if possible
- Refactor existing tests that share common code snippet (e.g. helper methods) and/or logic (e.g. set up a MiniDFSCluster). One approach that is not popular (which it should) is @Parameterized tests
- Reduce unnecessary overhead in unit tests (e.g. long interval sleep, build MiniDFSCluster multiple times instead of reusing the same one). Some of the cases were addressed by
This is not a long-term work to cover all future improvement in unit tests. We'll be happy to resolve this after our internal test cases (will file separate JIRAs for that) are mostly addressed/considered.