Add CSS class tests for check boxes and radio buttons

tests/toggles/test_checkbox.py

@@ -22,6 +22,11 @@ async def test_checkbox_initial_state() -> None:
     """The initial states of the check boxes should be as we specified."""
     async with CheckboxApp().run_test() as pilot:
         assert [box.value for box in pilot.app.query(Checkbox)] == [False, False, True]
+        assert [box.has_class("-on") for box in pilot.app.query(Checkbox)] == [
+            False,
+            False,
+            True,
+        ]
         assert pilot.app.events_received == []
 
 
@@ -31,6 +36,11 @@ async def test_checkbox_toggle() -> None:
         for box in pilot.app.query(Checkbox):
             box.toggle()
         assert [box.value for box in pilot.app.query(Checkbox)] == [True, True, False]
+        assert [box.has_class("-on") for box in pilot.app.query(Checkbox)] == [
+            True,
+            True,
+            False,
+        ]
         await pilot.pause()
         assert pilot.app.events_received == [
             ("cb1", True),

tests/toggles/test_radiobutton.py

@@ -26,6 +26,11 @@ async def test_radio_button_initial_state() -> None:
             False,
             True,
         ]
+        assert [button.has_class("-on") for button in pilot.app.query(RadioButton)] == [
+            False,
+            False,
+            True,
+        ]
         assert pilot.app.events_received == []
 
 
@@ -39,6 +44,11 @@ async def test_radio_button_toggle() -> None:
             True,
             False,
         ]
+        assert [button.has_class("-on") for button in pilot.app.query(RadioButton)] == [
+            True,
+            True,
+            False,
+        ]
         await pilot.pause()
         assert pilot.app.events_received == [
             ("rb1", True),