QMessageBox::question returning NoButton?

patrickkidd

I am running pytest and PyQt-5 with QT_QPA_PLATFORM=offscreen and QMessageBox::question is returning NoButton, but only when many other unit tests are running first. The test runs fine alone. I have debugged the qt code from QMessageBox::question on down and for some reason QMessageBoxPrivate::_q_buttonClicked is never called.

I can't include an example here because this is a complicated integration test. But it is clear that the QEventLoop in QDialog::exec is not executing anything.

Under what conditions would this occur? The documentation doesn't help. Thanks!

patrickkidd

@patrickkidd Turns out my code was calling QApplication::quit at some point in one of the prior unit tests. So the answer is that QMessageBox::question (and the other static methods, and probably also QDialog) quietly returns the default - NoButton - when the application has quit.

SGaist

Hi,

Out of curiosity, are you monkeypatching your QMessageBox for the tests ?

Otherwise how are you making the that part work while testing ?

patrickkidd

@SGaist said in QMessageBox::question returning NoButton?:

Hi,

Out of curiosity, are you monkeypatching your QMessageBox for the tests ?

Otherwise how are you making the that part work while testing ?

qtbot.clickYesAfter(lambda: model.removeTag(1))

from pytestqt.qtbot import QtBot

class PKQtBot(QtBot):

    def qWaitForMessageBox(self, action, contains=None, handleClick=None):
        from PyQt5.QtWidgets import QAbstractButton
        msgBoxAccepted = util.Condition()
        def acceptMessageBox():
            box = QApplication.activeModalWidget()
            if box:
                if contains:
                    assert contains in box.text()
                if handleClick:
                    handleClick()
                    msgBoxAccepted()
                    msgBoxAccepted.timer.stop()
                else:
                    okButton = box.button(QMessageBox.Ok)
                    box.buttonClicked[QAbstractButton].connect(msgBoxAccepted)
                    msgBoxAccepted()
                    self.mouseClick(okButton, Qt.LeftButton)
                    msgBoxAccepted.timer.stop()
        msgBoxAccepted.timer = QTimer(QApplication.instance())
        msgBoxAccepted.timer.timeout.connect(acceptMessageBox)
        msgBoxAccepted.timer.start(100)
        action()
        msgBoxAccepted.wait()
    
    def clickYesAfter(self, action):
        def doClickYes():
            self.mouseClick(QApplication.activeModalWidget().button(QMessageBox.Yes),
                            Qt.LeftButton)
        self.qWaitForMessageBox(action, handleClick=doClickYes)
        
    def clickNoAfter(self, action):
        def doClickNo():
            self.mouseClick(QApplication.activeModalWidget().button(QMessageBox.No),
                            Qt.LeftButton)
        self.qWaitForMessageBox(action, handleClick=doClickNo)


@pytest.yield_fixture
def qtbot(qApp, request):
    """ Overridden to use our qApp, because the old one was calling abort(). """
    result = PKQtBot(request)
    util.qtbot = result
    yield result

I also have another one that uses my custom Condition class, which can be used to wait for a lambda or keep track of signal calls:

    def waitUntil(self, condition, timeout=2000):
        util.Condition(condition=condition).wait(maxMS=timeout)

class Condition(Debug):
    """ Allows you to wait for a signal to be called. """
    def __init__(self, only=None, condition=None):
        self.callCount = 0
        self.callArgs = []
        self.senders = []
        self.lastCallArgs  = None
        self.only = only
        self.condition = condition

    def reset(self):
        self.callCount = 0
        self.callArgs = []
        self.senders = []
        self.lastCallArgs = None

    def test(self):
        """ Return true if the condition is true. """
        if self.condition:
            return self.condition()
        else:
            self.callCount > 0

    def set(self, *args):
        """ Set the condition to true. Alias for condition(). """
        self.callCount += 1
        self.senders.append(QObject().sender())
        self.lastCallArgs = args
        self.callArgs.append(args)

    def __call__(self, *args):
        """ Called by whatever signal that triggers the condition. """
        if self.only:
            only = self.only
            if not only(*args):
                return
        self.set(*args)

    def wait(self, maxMS=2000, onError=None):
        """ Wait for the condition to be true. onError is a callback. """
        startTime = time.time()
        success = True
        app = QApplication.instance()
        while app and not self.test():
            try:
                app.processEvents(QEventLoop.WaitForMoreEvents, 100)
            except KeyboardInterrupt as e:
                if onError:
                    onError()
                break
            elapsed = ((time.time() - startTime) * 1000)
            if elapsed >= maxMS:
                break