Moved QApplication into one test

Tests/test_imageqt.py

@@ -8,27 +8,6 @@
     from PIL.ImageQt import qRgba
 
 
-@pytest.mark.skipif(not ImageQt.qt_is_installed, reason="Qt bindings are not installed")
-class PillowQPixmapTestCase:
-    @classmethod
-    def setup_class(self):
-        try:
-            if ImageQt.qt_version == "5":
-                from PyQt5.QtGui import QGuiApplication
-            elif ImageQt.qt_version == "side2":
-                from PySide2.QtGui import QGuiApplication
-        except ImportError:
-            pytest.skip("QGuiApplication not installed")
-            return
-
-        self.app = QGuiApplication([])
-
-    @classmethod
-    def teardown_class(self):
-        self.app.quit()
-        self.app = None
-
-
 @pytest.mark.skipif(not ImageQt.qt_is_installed, reason="Qt bindings are not installed")
 def test_rgb():
     # from https://doc.qt.io/archives/qt-4.8/qcolor.html

Tests/test_qt_image_qapplication.py

@@ -0,0 +1,63 @@
+import pytest
+
+from PIL import ImageQt
+
+from .helper import assert_image_equal, hopper
+
+if ImageQt.qt_is_installed:
+    from PIL.ImageQt import QPixmap
+
+    if ImageQt.qt_version == "5":
+        from PyQt5 import QtGui
+        from PyQt5.QtWidgets import QApplication, QHBoxLayout, QLabel, QWidget
+    elif ImageQt.qt_version == "side2":
+        from PySide2 import QtGui
+        from PySide2.QtWidgets import QApplication, QHBoxLayout, QLabel, QWidget
+
+    class Example(QWidget):
+        def __init__(self):
+            super().__init__()
+
+            img = hopper().resize((1000, 1000))
+
+            qimage = ImageQt.ImageQt(img)
+
+            pixmap1 = QtGui.QPixmap.fromImage(qimage)
+
+            QHBoxLayout(self)  # hbox
+
+            lbl = QLabel(self)
+            # Segfault in the problem
+            lbl.setPixmap(pixmap1.copy())
+
+
+def roundtrip(expected):
+    result = ImageQt.fromqpixmap(ImageQt.toqpixmap(expected))
+    # Qt saves all pixmaps as rgb
+    assert_image_equal(result, expected.convert("RGB"))
+
+
+@pytest.mark.skipif(not ImageQt.qt_is_installed, reason="Qt bindings are not installed")
+def test_sanity(tmp_path):
+    # Segfault test
+    app = QApplication([])
+    ex = Example()
+    assert app  # Silence warning
+    assert ex  # Silence warning
+
+    for mode in ("1", "RGB", "RGBA", "L", "P"):
+        # to QPixmap
+        data = ImageQt.toqpixmap(hopper(mode))
+
+        assert isinstance(data, QPixmap)
+        assert not data.isNull()
+
+        # Test saving the file
+        tempfile = str(tmp_path / f"temp_{mode}.png")
+        data.save(tempfile)
+
+        # from QPixmap
+        roundtrip(hopper(mode))
+
+    app.quit()
+    app = None

Tests/test_qt_image_toqimage.py

@@ -11,13 +11,6 @@
 if ImageQt.qt_is_installed:
     from PIL.ImageQt import QImage
 
-    try:
-        from PyQt5 import QtGui
-        from PyQt5.QtWidgets import QApplication, QHBoxLayout, QLabel, QWidget
-    except (ImportError, RuntimeError):
-        from PySide2 import QtGui
-        from PySide2.QtWidgets import QApplication, QHBoxLayout, QLabel, QWidget
-
 
 def test_sanity(tmp_path):
     for mode in ("RGB", "RGBA", "L", "P", "1"):
@@ -49,29 +42,3 @@ def test_sanity(tmp_path):
         # Check that it actually worked.
         with Image.open(tempfile) as reloaded:
             assert_image_equal(reloaded, src)
-
-
-def test_segfault():
-    app = QApplication([])
-    ex = Example()
-    assert app  # Silence warning
-    assert ex  # Silence warning
-
-
-if ImageQt.qt_is_installed:
-
-    class Example(QWidget):
-        def __init__(self):
-            super().__init__()
-
-            img = hopper().resize((1000, 1000))
-
-            qimage = ImageQt.ImageQt(img)
-
-            pixmap1 = QtGui.QPixmap.fromImage(qimage)
-
-            QHBoxLayout(self)  # hbox
-
-            lbl = QLabel(self)
-            # Segfault in the problem
-            lbl.setPixmap(pixmap1.copy())