refactor(tui): extract _select_origin_widget helper + add unit tests

frontends/tuiapp_v2.py

@@ -583,6 +583,16 @@ def _sidebar_last_user(sess: AgentSession) -> str:
     return ""
 
 
+# Textual 8.2.6 renamed _select_start to _select_state (SelectState.start.container).
+def _select_origin_widget(screen: Any) -> Any:
+    state = getattr(screen, "_select_state", None)
+    if state is not None:
+        start = getattr(state, "start", None)
+        return start.container if start is not None else None
+    legacy = getattr(screen, "_select_start", None)
+    return legacy[0] if legacy is not None else None
+
+
 def _sidebar_last_summary(sess: AgentSession) -> str:
     try:
         history = sess.agent.llmclient.backend.history
@@ -870,13 +880,7 @@ def patched(select_widget, mouse_coord, delta_y):
             scroll_lines = app.SELECT_AUTO_SCROLL_LINES
 
             candidates = [select_widget]
-            # Textual 8.2.6 renamed _select_start to _select_state (SelectState.start.container).
-            select_state = getattr(screen, "_select_state", None)
-            if select_state is not None:
-                sw = select_state.start.container
-            else:
-                ss = getattr(screen, "_select_start", None)
-                sw = ss[0] if ss is not None else None
+            sw = _select_origin_widget(screen)
             if sw is not None and sw is not select_widget:
                 candidates.append(sw)
 

tests/test_tuiapp_v2_select_origin.py

@@ -0,0 +1,169 @@
+import importlib
+import sys
+import types
+import unittest
+from pathlib import Path
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+FRONTENDS = REPO_ROOT / "frontends"
+for path in (str(REPO_ROOT), str(FRONTENDS)):
+    if path not in sys.path:
+        sys.path.insert(0, path)
+
+
+def _install_import_stubs():
+    rich = types.ModuleType("rich")
+    rich_markdown = types.ModuleType("rich.markdown")
+
+    class Markdown:
+        def __init__(self, markup, **kwargs):
+            self.parsed = []
+
+    rich_markdown.Markdown = Markdown
+
+    rich_table = types.ModuleType("rich.table")
+    rich_table.Table = type("Table", (), {})
+
+    rich_text = types.ModuleType("rich.text")
+    rich_text.Text = type("Text", (), {})
+
+    textual = types.ModuleType("textual")
+    textual.events = types.ModuleType("textual.events")
+
+    class _Base:
+        BINDINGS: list = []
+        def __init__(self, *a, **kw):
+            pass
+        def __init_subclass__(cls, **kw):
+            super().__init_subclass__()
+        def __class_getitem__(cls, item):
+            return cls
+
+    textual_app = types.ModuleType("textual.app")
+    textual_app.App = type("App", (_Base,), {})
+    textual_app.ComposeResult = object
+
+    textual_binding = types.ModuleType("textual.binding")
+
+    class Binding:
+        def __init__(self, *a, **kw):
+            self.args = a
+            self.kwargs = kw
+
+    textual_binding.Binding = Binding
+
+    textual_containers = types.ModuleType("textual.containers")
+    textual_containers.Horizontal = type("Horizontal", (_Base,), {})
+    textual_containers.Vertical = type("Vertical", (_Base,), {})
+    textual_containers.VerticalScroll = type("VerticalScroll", (_Base,), {})
+
+    textual_message = types.ModuleType("textual.message")
+    textual_message.Message = type("Message", (_Base,), {})
+
+    textual_screen = types.ModuleType("textual.screen")
+    textual_screen.ModalScreen = type("ModalScreen", (_Base,), {})
+
+    textual_widgets = types.ModuleType("textual.widgets")
+    textual_widgets.OptionList = type("OptionList", (_Base,), {})
+    textual_widgets.Static = type("Static", (_Base,), {})
+    textual_widgets.TextArea = type("TextArea", (_Base,), {})
+
+    textual_widgets_option_list = types.ModuleType("textual.widgets.option_list")
+    textual_widgets_option_list.Option = type("Option", (_Base,), {})
+
+    chatapp_common = types.ModuleType("chatapp_common")
+    chatapp_common.format_restore = lambda: (([], "", 0), None)
+
+    btw_cmd = types.ModuleType("btw_cmd")
+    btw_cmd.handle_frontend_command = lambda *a, **k: ""
+
+    continue_cmd = types.ModuleType("continue_cmd")
+    continue_cmd.handle_frontend_command = lambda *a, **k: ""
+    continue_cmd.list_sessions = lambda *a, **k: []
+    continue_cmd.extract_ui_messages = lambda *a, **k: []
+
+    export_cmd = types.ModuleType("export_cmd")
+    export_cmd.last_assistant_text = lambda *a, **k: ""
+    export_cmd.export_to_temp = lambda *a, **k: ""
+    export_cmd.wrap_for_clipboard = lambda *a, **k: ""
+
+    agentmain = types.ModuleType("agentmain")
+
+    class GeneraticAgent:
+        def __init__(self):
+            self.verbose = False
+
+    agentmain.GeneraticAgent = GeneraticAgent
+
+    sys.modules.update({
+        "rich": rich,
+        "rich.markdown": rich_markdown,
+        "rich.table": rich_table,
+        "rich.text": rich_text,
+        "textual": textual,
+        "textual.events": textual.events,
+        "textual.app": textual_app,
+        "textual.binding": textual_binding,
+        "textual.containers": textual_containers,
+        "textual.message": textual_message,
+        "textual.screen": textual_screen,
+        "textual.widgets": textual_widgets,
+        "textual.widgets.option_list": textual_widgets_option_list,
+        "chatapp_common": chatapp_common,
+        "btw_cmd": btw_cmd,
+        "continue_cmd": continue_cmd,
+        "export_cmd": export_cmd,
+        "agentmain": agentmain,
+    })
+
+
+_install_import_stubs()
+tuiapp_v2 = importlib.import_module("tuiapp_v2")
+
+
+class _Widget:
+    def __init__(self, name):
+        self.name = name
+
+
+class _SelectStart:
+    def __init__(self, container=None):
+        self.container = container
+
+
+class _SelectState:
+    def __init__(self, start):
+        self.start = start
+
+
+class SelectOriginWidgetTests(unittest.TestCase):
+    def test_textual_8x_returns_select_state_start_container(self):
+        container = _Widget("messages")
+        screen = types.SimpleNamespace(_select_state=_SelectState(_SelectStart(container=container)))
+        self.assertIs(tuiapp_v2._select_origin_widget(screen), container)
+
+    def test_textual_8x_select_state_none_returns_none(self):
+        screen = types.SimpleNamespace(_select_state=None)
+        self.assertIsNone(tuiapp_v2._select_origin_widget(screen))
+
+    def test_textual_8x_start_none_returns_none(self):
+        screen = types.SimpleNamespace(_select_state=_SelectState(start=None))
+        self.assertIsNone(tuiapp_v2._select_origin_widget(screen))
+
+    def test_legacy_textual_7x_returns_first_element_of_select_start_tuple(self):
+        widget = _Widget("legacy")
+        screen = types.SimpleNamespace(_select_start=(widget, (0, 0)))
+        self.assertIs(tuiapp_v2._select_origin_widget(screen), widget)
+
+    def test_legacy_textual_7x_select_start_none_returns_none(self):
+        screen = types.SimpleNamespace(_select_start=None)
+        self.assertIsNone(tuiapp_v2._select_origin_widget(screen))
+
+    def test_neither_attribute_returns_none(self):
+        screen = types.SimpleNamespace()
+        self.assertIsNone(tuiapp_v2._select_origin_widget(screen))
+
+
+if __name__ == "__main__":
+    unittest.main()