function expectAndDelete(fullPath) {
            runs(function () {
                var promise = SpecRunnerUtils.resolveNativeFileSystemPath(fullPath);
                waitsForDone(promise, "Verify file exists: " + fullPath);
            });
            runs(function () {
                var promise = SpecRunnerUtils.deletePath(fullPath);
                waitsForDone(promise, "Remove testfile " + fullPath, 5000);
            });
        }
Expect a file to exist (failing test if not) and then delete it