I'm a student thinking of participating in Google Summer of Code.
And want to work to create a unittest for IDLE.

Using unittest.mock seemed to be good way to test GUI.
But there is a problem.
There is no unittest.mock in Python2.
http://docs.python.org/2/library/unittest.html

I think using third party mock seemed to be ok, but not best way.
https://pypi.python.org/pypi/mock
Because, IDLE is a part of official python.
I think relying on third party module is not good.

Of cource, I would forcus on non-GUI unittest.
But GUI-test would be needed.