unit tests

[s-pic]

Hi! I integrated useHasOverflow in our TSX app and it helped me a lot, so first of all thanks for that.
Now I will have to write tests for it since we want all used code to be test-covered, which also goes for dependencies.
I would like to give back to this repo and submit the test code.

So my questions are:

• are you open for a PR here?
• are you planning to add a testing setup any time soon? Prep work here would keep the scope of that eventual PR as small as possible

[steabert]

We are definitely open to PRs!

We're not currently working on adding a test setup here, but would be interested if someone wants to work on that.