Steve Holden wrote:
"Fail" isn't a negative.
That depends on what you're trying to find out by reading the code. If you're trying to find out under what conditions the test succeeds, then it succeeds if it doesn't fail, so you have a negative.
Whichever convention is chosen, there will be situations in which you want to mentally negate it. If you start with a positive, the mental negation produces a single negative. If you start with a negative, the mental negation produces a double negative. Therefore it is less confusing overall to start with as few negatives as possible.