A note about Modal Dialogs

Simple Dialogs

For QMessageBox.question one approach is to mock the function using the monkeypatch fixture:

def test_Qt(qtbot, monkeypatch):
    simple = Simple()

    monkeypatch.setattr(QMessageBox, 'question', lambda *args: QMessageBox.Yes)
    assert simple.answer

Custom Dialogs

Suppose you have a custom dialog that asks the user for their name and age, and a form that uses it. One approach is to add a convenience function that also has the nice benefit of making testing easier, like this:

class AskNameAndAgeDialog(QDialog):
    def ask(cls, text, parent):
        dialog = cls(parent)
        if dialog.exec_() == QDialog.Accepted:
             return dialog.getName(), dialog.getAge()
             return None, None

This allows clients of the dialog to use it this way:

name, age = AskNameAndAgeDialog.ask("Enter name and age because of bananas:", parent)
if name is not None:
    # use name and age for bananas

And now it is also easy to mock AskNameAndAgeDialog.ask when testing the form:

def test_form_registration(qtbot, monkeypatch):
    form = RegistrationForm()

    monkeypatch.setattr(AskNameAndAgeDialog, 'ask', classmethod(lambda *args: ('Jonh', 30)))
    # calls AskNameAndAgeDialog.ask
    # test that the rest of the form correctly behaves as if
    # user entered "Jonh" and 30 as name and age