Add a unit test for Textualize#2807

tests/test_tabbed_content.py

@@ -369,6 +369,44 @@ def on_tabbed_content_cleared(self) -> None:
         assert tabbed_content.active == ""
 
 
+@pytest.mark.xfail(
+    reason="https://github.com/Textualize/textual/issues/2807", strict=True
+)
+async def test_tabbed_content_reversed_removal():
+    class TabbedApp(App[None]):
+        cleared: var[int] = var(0)
+
+        def compose(self) -> ComposeResult:
+            with TabbedContent():
+                yield TabPane("Test 1", id="initial-1")
+                yield TabPane("Test 2", id="initial-2")
+                yield TabPane("Test 3", id="initial-3")
+
+        def on_tabbed_content_cleared(self) -> None:
+            self.cleared += 1
+
+    async with TabbedApp().run_test() as pilot:
+        tabbed_content = pilot.app.query_one(TabbedContent)
+        assert tabbed_content.tab_count == 3
+        assert pilot.app.cleared == 0
+        assert tabbed_content.active == "initial-1"
+        await tabbed_content.remove_pane("initial-3")
+        await pilot.pause()
+        assert tabbed_content.tab_count == 2
+        assert pilot.app.cleared == 0
+        assert tabbed_content.active == "initial-1"
+        await tabbed_content.remove_pane("initial-2")
+        await pilot.pause()
+        assert tabbed_content.tab_count == 1
+        assert pilot.app.cleared == 0
+        assert tabbed_content.active == "initial-1"
+        await tabbed_content.remove_pane("initial-1")
+        await pilot.pause()
+        assert tabbed_content.tab_count == 0
+        assert pilot.app.cleared == 1
+        assert tabbed_content.active == ""
+
+
 async def test_tabbed_content_clear():
     class TabbedApp(App[None]):
         cleared: var[int] = var(0)