Previously, every AppKit tests used the same sharedApplication. Due to this implementation, a could not pass because a previous test made failed the current test. For instance, a test could fail because the window of the previous test resigned (just imagine a new window is the key window in the current test), and this resign could raise an error. The error was displayed for the current test thought this test was perfect !
We now instead of using sharedApplication create a new CPApplication per unit-test file in the class method setUp.
Alexandre Wilhelm