Behaviour of waitSignal

[baudren]

Problem description

I am having troubles with understanding how to use the functionality qtbot.waitSignal. I followed the documentation but there must be something I am missing.

It seems that a direct call to the emit method of a given signal does not trigger a block with qtbot.waitSignal(... to validate.

I found the problem by testing my application, checking if a button was sending a signal, and noted that the waitSignal was always hitting the timeout. I extracted what I think is a bug, but might be to my very new discovery of signals and slots.

What I expected / what I get

in a file test_sample.py:

from PySide.QtCore import QObject, Signal

class Simple(QObject):
    signal = Signal()

def test_Qt(qtbot):
    simple = Simple()

    with qtbot.waitSignal(simple.signal, timeout=1000) as waiting:
        simple.signal.emit()

    assert waiting.signal_triggered

Running py.test on this file results in an AssertionError, because waiting.signal_triggered is False. I expected the emit method to cause waiting to see the signal being emitted.

Possible things I might do wrong

Since I am new to this signal/slot business, I might be overlooking some essential facts.

• As a zen master would ask, is the signal truly fired if no slot is there to listen to it?
• Could it be that it is that slow to fire a signal?
• Is the emit code somehow placed at the wrong spot?

Thank you for enlightening me, and thanks for sharing such a useful work, by the way. Testing GUI applications without this would be a massive pain.

Configuration

I am using Python 2.7.5, pytest 1.4.24, and PySide 1.2.2, on a Linux Mint 16.

[nicoddemus]

Hi,

Ouch, you found a bug! 😅

Usually the code inside a waitSignal block schedules an event that will be processed in the next event loop, for example:

def test_window(qtbot, widget):
    with qtbot.waitSignal(app.worker.finished, timeout=10000) as blocker:
        # start() will schedule the signal to be emitted in the next event loop
        app.worker.start() 

but your example is triggering it immediately inside the block.

I'm working on a fix and will publish a new release.

Many thanks! 😄
Cheers,

[nicoddemus]

Published 1.2.1. Thanks again! 😄

[baudren]

Wow, thanks to you for such a quick reaction! Looking forward to playtest my application, now!

[nicoddemus]

Nice, thanks again! 😄
Em 11/09/2014 04:11, "baudren" [email protected] escreveu:

Wow, thanks to you for such a quick reaction! Looking forward to playtest
my application, now!

—
Reply to this email directly or view it on GitHub
https://github.com/nicoddemus/pytest-qt/issues/16#issuecomment-55228082.

[jdreaver]

I just encountered this bug, and was about to make a fix. Next thing I know it's already fixed! I can't believe we left instantaneous signals out of our original tests for this feature. Thanks @baudren and @nicoddemus!

[nicoddemus]

@jdreaver I don't believe it either, hehehe! 😅