fix: fix callback of throttled/debounced decorated functions with mismatched args (#184)

* fix: fix throttled inspection

* build: change typing-ext deps

* fix: use inspect.signature

* use get_max_args

* fix: fix typing

tests/test_throttler.py

@@ -1,5 +1,8 @@
 from unittest.mock import Mock
 
+import pytest
+from qtpy.QtCore import QObject, Signal
+
 from superqt.utils import qdebounced, qthrottled
 
 
@@ -41,3 +44,29 @@ def test_throttled(qtbot):
     qtbot.wait(5)
     assert mock1.call_count == 2
     assert mock2.call_count == 10
+
+
+@pytest.mark.parametrize("deco", [qthrottled, qdebounced])
+def test_ensure_throttled_sig_inspection(deco, qtbot):
+    mock = Mock()
+
+    class Emitter(QObject):
+        sig = Signal(int, int, int)
+
+    @deco
+    def func(a: int, b: int):
+        """docstring"""
+        mock(a, b)
+
+    obj = Emitter()
+    obj.sig.connect(func)
+
+    # this is the crux of the test...
+    # we emit 3 args, but the function only takes 2
+    # this should normally work fine in Qt.
+    # testing here that the decorator doesn't break it.
+    with qtbot.waitSignal(func.triggered, timeout=1000):
+        obj.sig.emit(1, 2, 3)
+    mock.assert_called_once_with(1, 2)
+    assert func.__doc__ == "docstring"
+    assert func.__name__ == "func"