fix(tabs): update highlighting when tab removed

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Fixed duplicated key displays in the help panel https://github.com/Textualize/textual/issues/5037
 - Fixed `TextArea` mouse selection with tab characters https://github.com/Textualize/textual/issues/5212
+- Fixed `Tabs` not updating the highlighting after removing a tab https://github.com/Textualize/textual/issues/5218
 
 ### Added
 

src/textual/widgets/_tabs.py

@@ -556,10 +556,12 @@ def remove_tab(self, tab_or_id: Tab | str | None) -> AwaitComplete:
         async def do_remove() -> None:
             """Perform the remove after refresh so the underline bar gets new positions."""
             await remove_tab.remove()
-            if next_tab is not None:
-                self.active = next_tab.id or ""
             if not self.query("#tabs-list > Tab"):
                 self.active = ""
+            elif next_tab is not None:
+                self.active = next_tab.id or ""
+            else:
+                self._highlight_active(animate=False)
 
         return AwaitComplete(do_remove())
 

tests/snapshot_tests/test_snapshots.py

@@ -30,6 +30,8 @@
     SelectionList,
     Static,
     Switch,
+    Tab,
+    Tabs,
     TextArea,
 )
 from textual.widgets.text_area import BUILTIN_LANGUAGES, Selection, TextAreaTheme
@@ -2547,3 +2549,25 @@ async def run_before(pilot: Pilot):
 
     app = HelpPanelApp()
     assert snap_compare(app, run_before=run_before)
+
+
+def test_tabs_remove_tab_updates_highlighting(snap_compare):
+    """Regression test for https://github.com/Textualize/textual/issues/5218"""
+
+    class TabsApp(App):
+        BINDINGS = [("r", "remove_foo", "Remove foo")]
+
+        def compose(self) -> ComposeResult:
+            yield Tabs(
+                Tab("foo", id="foo"),
+                Tab("bar", id="bar"),
+                active="bar",
+            )
+            yield Footer()
+
+        def action_remove_foo(self) -> None:
+            tabs = self.query_one(Tabs)
+            tabs.remove_tab("foo")
+
+    app = TabsApp()
+    assert snap_compare(app, press="r")