raise ValueError if hmenu==-1

msl/loadlib/activex.py

@@ -372,6 +372,10 @@ def checked(self) -> bool:
     @checked.setter
     def checked(self, value: bool) -> None:
         """Set the checked state of the menu item."""
+        if self._hmenu == -1:
+            raise ValueError('A MenuItem must first be added to a Menu '
+                             'before it can be checked')
+
         # MF_CHECKED=8, MF_UNCHECKED=0
         state = 8 if value else 0
         previous = user32.CheckMenuItem(self._hmenu, self._id, state)
@@ -451,6 +455,9 @@ def checked(self) -> MenuItem | None:
     def checked(self, item: MenuItem | None) -> None:
         """Sets the menu item that is currently checked in the group."""
         for i in self:
+            if i.hmenu == -1:
+                raise ValueError('A MenuGroup must first be added to a Menu '
+                                 'before a MenuItem can be checked')
             i.checked = i == item
 
     @property

tests/test_application.py

@@ -22,6 +22,11 @@ def test_menu_item():
     mi2 = activex.MenuItem(hmenu=123, id=8, text='hello world', callback=None, flags=1, data=[-1, 0, 1])
     assert mi != mi2  # IDs do not match
 
+    mi3 = activex.MenuItem(hmenu=-1, id=1, text='a', callback=None, flags=0, data=None)
+
+    with pytest.raises(ValueError, match='A MenuItem must first be added to a Menu'):
+        mi3.checked = True
+
 
 def test_menu_group():
     mg = activex.MenuGroup()
@@ -33,15 +38,20 @@ def test_menu_group():
     a = mg.append('a')
     assert isinstance(a, activex.MenuItem)
     mg.append('b', data=8, flags=activex.MenuFlag.POPUP)
+    mg.append_separator()
     mg.append('c', callback=None)
     assert mg.name == 'click'
     assert mg.checked is None
-    assert str(mg) == "<MenuGroup name='click' size=3>"
+    assert str(mg) == "<MenuGroup name='click' size=4>"
 
     for item in mg:
         assert isinstance(item, activex.MenuItem)
         assert item.checked is False
 
+    for item in [a, None]:
+        with pytest.raises(ValueError, match='A MenuGroup must first be added to a Menu'):
+            mg.checked = item
+
 
 @skipif_not_windows
 def test_menu():