test: Add tests for slider behavior with equal min and max values (#310)

src/superqt/sliders/_generic_slider.py

@@ -349,7 +349,7 @@ class _GenericSlider(QSlider):
         _max = _max or self.MAX_DISPLAY
         range_ = self._maximum - self._minimum
         if range_ == 0:
-            return self._minimum
+            return 0
         return int(min(QOVERFLOW, val / range_ * _max))
 
     def _pick(self, pt: QPoint) -> int:

tests/zz_test_sliders/test_range_slider.py

@@ -254,3 +254,39 @@ def test_rangeslider_signals(cls, orientation, qtbot):
         sld.setRange(1, 2)
     mock.assert_called_once_with(1, 2)
     _assert_types(mock.call_args.args, type_)
+
+
+@pytest.mark.parametrize("cls, orientation", ALL_SLIDER_COMBOS)
+def test_range_slider_with_equal_min_max(cls, orientation, qtbot):
+    """Test that slider works when min == max (issue #307).
+
+    Previously, this would raise a TypeError: 'float' object cannot be
+    interpreted as an integer when calling show() because _to_qinteger_space
+    returned a float instead of an int when range was 0.
+    """
+    sld = cls(orientation)
+    qtbot.addWidget(sld)
+
+    # Test with min=max=99 (the specific case from issue #307)
+    with qtbot.waitSignal(sld.rangeChanged):
+        sld.setMinimum(99)
+
+    # This should not raise a TypeError
+    sld.show()
+
+    # Verify the slider state
+    assert sld.minimum() == 99
+    assert sld.maximum() == 99
+    assert sld.value() == (99, 99)
+
+    # Test that we can also set max first
+    sld2 = cls(orientation)
+    qtbot.addWidget(sld2)
+
+    with qtbot.waitSignal(sld2.rangeChanged):
+        sld2.setMaximum(0)
+
+    sld2.show()
+    assert sld2.minimum() == 0
+    assert sld2.maximum() == 0
+    assert sld2.value() == (0, 0)

tests/zz_test_sliders/test_single_value_sliders.py

@@ -229,3 +229,32 @@ def test_slider_extremes(sld: _GenericSlider, mag, qtbot):
     for i in _linspace(-_mag, _mag, 10):
         sld.setValue(i)
         assert math.isclose(sld.value(), i, rel_tol=1e-8)
+
+
+def test_slider_with_equal_min_max(sld: _GenericSlider, qtbot):
+    """Test that slider works when min == max (issue #307).
+
+    Previously, this would raise a TypeError: 'float' object cannot be
+    interpreted as an integer when calling show() because _to_qinteger_space
+    returned a float instead of an int when range was 0.
+    """
+    # Test with min=max=99 (the specific case from issue #307)
+    with qtbot.waitSignal(sld.rangeChanged, timeout=400):
+        sld.setMinimum(99)
+
+    # This should not raise a TypeError
+    sld.show()
+
+    # Verify the slider state
+    assert sld.minimum() == 99
+    assert sld.maximum() == 99
+    assert sld.value() == 99
+
+    # Test that we can also set max first
+    with qtbot.waitSignal(sld.rangeChanged, timeout=400):
+        sld.setMaximum(0)
+
+    sld.show()
+    assert sld.minimum() == 0
+    assert sld.maximum() == 0
+    assert sld.value() == 0