test fix

src/textual/app.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import asyncio
+from asyncio import Task
 from contextlib import asynccontextmanager
 import inspect
 import io
@@ -15,7 +16,6 @@ from pathlib import Path, PurePath
 from time import perf_counter
 from typing import (
     Any,
-    Awaitable,
     Callable,
     Coroutine,
     Generic,
@@ -654,7 +654,7 @@ class App(Generic[ReturnType], DOMNode):
             await app._process_messages(ready_callback=on_app_ready, headless=headless)
 
         # Launch the app in the "background"
-        asyncio.create_task(run_app(app))
+        app_task = asyncio.create_task(run_app(app))
 
         # Wait until the app has performed all startup routines.
         await app_ready_event.wait()
@@ -664,12 +664,13 @@ class App(Generic[ReturnType], DOMNode):
 
         # Shutdown the app cleanly
         await app._shutdown()
+        await app_task
 
     async def run_async(
         self,
         *,
         headless: bool = False,
-        auto_pilot: AutopilotCallbackType,
+        auto_pilot: AutopilotCallbackType | None = None,
     ) -> ReturnType | None:
         """Run the app asynchronously.
 
@@ -684,8 +685,11 @@ class App(Generic[ReturnType], DOMNode):
 
         app = self
 
+        auto_pilot_task: Task | None = None
+
         async def app_ready() -> None:
             """Called by the message loop when the app is ready."""
+            nonlocal auto_pilot_task
             if auto_pilot is not None:
 
                 async def run_auto_pilot(pilot) -> None:
@@ -696,17 +700,25 @@ class App(Generic[ReturnType], DOMNode):
                         raise
 
                 pilot = Pilot(app)
-                asyncio.create_task(run_auto_pilot(pilot))
+                auto_pilot_task = asyncio.create_task(run_auto_pilot(pilot))
+
+        try:
+            await app._process_messages(
+                ready_callback=None if auto_pilot is None else app_ready,
+                headless=headless,
+            )
+        finally:
+            if auto_pilot_task is not None:
+                await auto_pilot_task
+            await app._shutdown()
 
-        await app._process_messages(ready_callback=app_ready, headless=headless)
-        await app._shutdown()
         return app.return_value
 
     def run(
         self,
         *,
         headless: bool = False,
-        auto_pilot: AutopilotCallbackType,
+        auto_pilot: AutopilotCallbackType | None = None,
     ) -> ReturnType | None:
         """Run the app.
 
@@ -1287,8 +1299,10 @@ class App(Generic[ReturnType], DOMNode):
             parent (Widget): The parent of the Widget.
             widget (Widget): The Widget to start.
         """
+
         widget._attach(parent)
         widget._start_messages()
+        self.app._registry.add(widget)
 
     def is_mounted(self, widget: Widget) -> bool:
         """Check if a widget is mounted.
@@ -1321,6 +1335,7 @@ class App(Generic[ReturnType], DOMNode):
 
     async def _shutdown(self) -> None:
         driver = self._driver
+        self._running = False
         if driver is not None:
             driver.disable_input()
         await self._close_all()
@@ -1328,7 +1343,6 @@ class App(Generic[ReturnType], DOMNode):
 
         await self._dispatch_message(events.UnMount(sender=self))
 
-        self._running = False
         self._print_error_renderables()
         if self.devtools is not None and self.devtools.is_connected:
             await self._disconnect_devtools()

src/textual/message_pump.py

@@ -155,7 +155,9 @@ class MessagePump(metaclass=MessagePumpMeta):
                 return self._pending_message
             finally:
                 self._pending_message = None
+
         message = await self._message_queue.get()
+
         if message is None:
             self._closed = True
             raise MessagePumpClosed("The message pump is now closed")
@@ -289,7 +291,8 @@ class MessagePump(metaclass=MessagePumpMeta):
 
     def _start_messages(self) -> None:
         """Start messages task."""
-        self._task = asyncio.create_task(self._process_messages())
+        if self.app._running:
+            self._task = asyncio.create_task(self._process_messages())
 
     async def _process_messages(self) -> None:
         self._running = True

src/textual/widget.py

@@ -595,7 +595,6 @@ class Widget(DOMNode):
             vertical=False, name="horizontal", thickness=self.scrollbar_size_horizontal
         )
         self._horizontal_scrollbar.display = False
-
         self.app._start_widget(self, scroll_bar)
         return scroll_bar
 

tests/snapshot_tests/conftest.py

@@ -59,7 +59,6 @@ def snap_compare(
         """
         node = request.node
         app = import_app(app_path)
-        compare.app = app
         actual_screenshot = take_svg_screenshot(
             app=app,
             press=press,
@@ -69,7 +68,9 @@ def snap_compare(
 
         if result is False:
             # The split and join below is a mad hack, sorry...
-            node.stash[TEXTUAL_SNAPSHOT_SVG_KEY] = "\n".join(str(snapshot).splitlines()[1:-1])
+            node.stash[TEXTUAL_SNAPSHOT_SVG_KEY] = "\n".join(
+                str(snapshot).splitlines()[1:-1]
+            )
             node.stash[TEXTUAL_ACTUAL_SVG_KEY] = actual_screenshot
             node.stash[TEXTUAL_APP_KEY] = app
         else:
@@ -85,6 +86,7 @@ class SvgSnapshotDiff:
     """Model representing a diff between current screenshot of an app,
     and the snapshot on disk. This is ultimately intended to be used in
     a Jinja2 template."""
+
     snapshot: Optional[str]
     actual: Optional[str]
     test_name: str
@@ -119,7 +121,7 @@ def pytest_sessionfinish(
                     snapshot=str(snapshot_svg),
                     actual=str(actual_svg),
                     file_similarity=100
-                                    * difflib.SequenceMatcher(
+                    * difflib.SequenceMatcher(
                         a=str(snapshot_svg), b=str(actual_svg)
                     ).ratio(),
                     test_name=name,
@@ -176,7 +178,9 @@ def pytest_terminal_summary(
     if diffs:
         snapshot_report_location = config._textual_snapshot_html_report
         console.rule("[b red]Textual Snapshot Report", style="red")
-        console.print(f"\n[black on red]{len(diffs)} mismatched snapshots[/]\n"
+        console.print(
-                      f"\n[b]View the [link=file://{snapshot_report_location}]failure report[/].\n")
+            f"\n[black on red]{len(diffs)} mismatched snapshots[/]\n"
+            f"\n[b]View the [link=file://{snapshot_report_location}]failure report[/].\n"
+        )
         console.print(f"[dim]{snapshot_report_location}\n")
         console.rule(style="red")

tests/snapshot_tests/test_snapshots.py

@@ -66,22 +66,11 @@ def test_input_and_focus(snap_compare):
     ]
     assert snap_compare("docs/examples/widgets/input.py", press=press)
 
-    # Assert that the state of the Input is what we'd expect
-    # app: App = snap_compare.app
-    # input: Input = app.query_one(Input)
-    # assert input.value == "Darren"
-    # assert input.cursor_position == 6
-    # assert input.view_position == 0
-
 
 def test_buttons_render(snap_compare):
     # Testing button rendering. We press tab to focus the first button too.
     assert snap_compare("docs/examples/widgets/button.py", press=["tab"])
 
-    # app = snap_compare.app
-    # button: Button = app.query_one(Button)
-    # assert app.focused is button
-
 
 def test_datatable_render(snap_compare):
     press = ["tab", "down", "down", "right", "up", "left"]