Code testing policy¶

When writing tests, please note the following rules:

1. Each code change MUST be covered with tests. The test for specific code change must fail if that change to code is reverted, i.e. the test must really cover the code change and not the general case. Bug fixes should have tests for failing case.

2. The tests MUST be in the same patchset with the code changes.

3. It’s permitted not to write tests in extreme cases. The extreme cases are:

   • hot-fix / bug-fix with Critical status.
   • patching during Feature Freeze (FF) or Hard Code Freeze (HCF).

   In this case, request for writing tests should be reported as a bug with technical-debt tag. It has to be related to the bug which was fixed with a patchset that didn’t have the tests included.

4. Before writing tests please consider which type(s) of testing is suitable for the unit/module you’re covering.

5. Test coverage should not be decreased.

6. Nailgun application can be sliced up to tree layers (Presentation, Object, Model). Consider usage of the unit testing if it is performed within one of the layers or implementing mock objects is not complicated.

7. The tests have to be isolated. The order and count of executions must not influence test results.

8. Tests must be repetitive and must always pass regardless of how many times they are run.

9. Parametrize tests to avoid testing many times the same behaviour but with different data. This gives an additional flexibility in the methods’ usage.

10. Follow DRY principle in tests code. If common code parts are present, please extract them to a separate method/class.

11. Unit tests are grouped by namespaces as corresponding unit. For instance, the unit is located at: nailgun/db/dl_detector.py, corresponding test would be placed in nailgun/test/unit/nailgun.db/test_dl_detector.py

12. Integration tests are grouped at the discretion of the developer.

13. Consider implementing performance tests for the cases:

    • new handler is added which depends on number of resources in the database.
    • new logic is added which parses/operates on elements like nodes.