Two minor style notes that I only realized inside of my IDE as I was merging. According to default Scala style guide, should be:

    tree.getOwner(file) must be equalTo owner.getName

instead of:

    tree.getOwner(file) must be equalTo(owner.getName())

(note the unnecessary parentheses).  Parentheses should only be used like this () if the function has side effects. And parens are not needed in specs because it's just more readable after the equalTo