This looks good. But it will have to be merged with #155. Care to find out what/how? I can merge that other test when the assert_not_equals are changed. It'll be easier to add to that test then (although it's possible even now, with some basic git trickery)

#155 is merged now, so the improvements from this pull request should be put on top of that file. Because they conflict now. :)

Most of these tests can just be ported, only a few dupes. And maybe you can also add a step-test with a non-integer value (so e.g. step=2.3 plus stepUp check new value)

@velmont It failed to merge the file propery.
I will send a new request. So, don't merge this request.

yeah, you should probably have done a rebase on top.

git fetch
git rebase master

But just do it by creating a new fresh branch yes :-)

About min, max attributes, I asked other experts and they said that it does not matter if those attributes are valid or not. It should just ignore it and act as if it does not exist.
(They said that we should focus month value like that.)