The format looks good.

The content looks skimpy. I am not familiar with Delegator and have not yet looked to see what more is needed. But this is enough to test working with a gui test.

This *is* a gui test. See msg190576. So it must be protected by requiring the gui resource. I am still investigating this subject, but I believe the following should work for the momemnt.

from test.resource import requires
...
class ...
    @classmethod
    def setUpClass(cls):
        requires('gui')

In a console, "python -m test test_idle" should report that test_delegator.Test_delegator was skipped, follows by other stuff. Please make the change, run from the console, and copy the result here. Add '-ugui' *before* 'test_idle' and Test_delegator should run.

As written, the empty root window is left to be closed by hand. The teardown method should have self.root.destroy(). That will destroy the children also, so I believe that is all that is needed.