Reporting mutation surviving which should not

[rossdrew]

In one of my tests, I create a memory object, then reset() it, setting all that memory to 0.

I have a test, which confirms that memory is set to 0 and not empty.

Pitest reports the line doing the reset() as

1. removed call to com/rox/emu/mem/SimpleMemory::reset → SURVIVED

but if I remove the specified reset() line, it throws an error as the array hasn't been set up, meaning the mutation is (or should be) covered.

[hcoles]

Your test uses the assert keyword instead of a test assertion.

If the JVM is not run with the -ea flag then none of the code within the assert statement is executed - the assert is effectively commented out.

It would appear that the gradle test runner is setting the flag in the when running the tests.

Pitest does not set the flag so that this type of test error is revealed.