In JavaScript, when there isn't a `break` or `return` statement inside a
`switch` case, the next case will be executed as well.
That wasn't a problem here because CoffeeScript automatically inserts a
`return` statement in this specific situation. However, since we don't
want to return the result of the `hide()` operation, it might be easy to
accidentally remove the `return` statement, causing the code to break.
I've added a test for the scenario where neither `break` nor `return`
statements are present, so we don't run into this error.
