it('accepts a parentDir function', function (done) {
    sandbox.stub(glob, 'sync').returns(['foo.js']);
    mock.expects('statSync').withArgs('foo.js').returns({ ctime: new Date(1) });
    mockUtil.expects('haveOtherFilesBeenModified').withArgs('baz/qux').returns(false);
    mockUtil.expects('hasFolderBeenModified').withArgs('baz/qux').returns(false);