We cannot create test cases for AccessWhen rules, secondly there is no testcases tab in such rule. But while saving we get a compliance warning which impacts our overall application score.
"You should create a test case for this rule to identify any regression issues that might occur when this rule is modified."
This should be addressed, either by having testcases or removing compliance warning.
Testing my memoy here, but a couple of things to try here:
Your Access When rule can reference a When rule as part of its implementation. When rules can have Test Cases. If you designed your Access When rule to do nothing other than call a corresponding When rule, and implement test cases on the When rule, then you have 100% test coverage for your Access When rule.