Merge pull request #1615 from Textualize/test-freeze

Fix for test freeze

CHANGELOG.md

@@ -45,6 +45,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed TextLog wrapping issue https://github.com/Textualize/textual/issues/1554
 - Fixed issue with TextLog not writing anything before layout https://github.com/Textualize/textual/issues/1498
 - Fixed an exception when populating a child class of `ListView` purely from `compose` https://github.com/Textualize/textual/issues/1588
+- Fixed freeze in tests https://github.com/Textualize/textual/issues/1608
 
 ## [0.9.1] - 2022-12-30
 

src/textual/_asyncio.py

@@ -0,0 +1,23 @@
+"""
+Compatibility layer for asyncio.
+
+"""
+
+from __future__ import annotations
+
+
+import sys
+
+__all__ = ["create_task"]
+
+if sys.version_info >= (3, 8):
+    from asyncio import create_task
+
+else:
+    import asyncio
+    from asyncio import create_task as _create_task
+    from typing import Awaitable
+
+    def create_task(coroutine: Awaitable, *, name: str | None = None) -> asyncio.Task:
+        """Schedule the execution of a coroutine object in a spawn task."""
+        return _create_task(coroutine)

src/textual/app.py

@@ -1,8 +1,6 @@
 from __future__ import annotations
 
 import asyncio
-from concurrent.futures import Future
-from functools import partial
 import inspect
 import io
 import os
@@ -12,8 +10,10 @@ import threading
 import unicodedata
 import warnings
 from asyncio import Task
+from concurrent.futures import Future
 from contextlib import asynccontextmanager, redirect_stderr, redirect_stdout
 from datetime import datetime
+from functools import partial
 from pathlib import Path, PurePath
 from queue import Queue
 from time import perf_counter
@@ -41,9 +41,10 @@ from rich.protocol import is_renderable
 from rich.segment import Segment, Segments
 from rich.traceback import Traceback
 
-from . import actions, Logger, LogGroup, LogVerbosity, events, log, messages
+from . import Logger, LogGroup, LogVerbosity, actions, events, log, messages
 from ._animator import DEFAULT_EASING, Animatable, Animator, EasingFunction
 from ._ansi_sequences import SYNC_END, SYNC_START
+from ._asyncio import create_task
 from ._callback import invoke
 from ._context import active_app
 from ._event_broker import NoHandler, extract_handler_actions
@@ -69,7 +70,6 @@ from .renderables.blank import Blank
 from .screen import Screen
 from .widget import AwaitMount, Widget
 
-
 if TYPE_CHECKING:
     from .devtools.client import DevtoolsClient
     from .pilot import Pilot
@@ -859,7 +859,7 @@ class App(Generic[ReturnType], DOMNode):
             )
 
         # Launch the app in the "background"
-        app_task = asyncio.create_task(run_app(app))
+        app_task = create_task(run_app(app), name=f"run_test {app}")
 
         # Wait until the app has performed all startup routines.
         await app_ready_event.wait()
@@ -914,7 +914,9 @@ class App(Generic[ReturnType], DOMNode):
                         raise
 
                 pilot = Pilot(app)
-                auto_pilot_task = asyncio.create_task(run_auto_pilot(auto_pilot, pilot))
+                auto_pilot_task = create_task(
+                    run_auto_pilot(auto_pilot, pilot), name=repr(pilot)
+                )
 
         try:
             await app._process_messages(
@@ -1653,6 +1655,7 @@ class App(Generic[ReturnType], DOMNode):
             return []
 
         new_widgets = list(widgets)
+
         if before is not None or after is not None:
             # There's a before or after, which means there's going to be an
             # insertion, so make it easier to get the new things in the
@@ -1668,6 +1671,11 @@ class App(Generic[ReturnType], DOMNode):
                 if widget.children:
                     self._register(widget, *widget.children)
                 apply_stylesheet(widget)
+
+        if not self._running:
+            # If the app is not running, prevent awaiting of the widget tasks
+            return []
+
         return list(widgets)
 
     def _unregister(self, widget: Widget) -> None:
@@ -2111,7 +2119,9 @@ class App(Generic[ReturnType], DOMNode):
         removed_widgets = self._detach_from_dom(widgets)
 
         finished_event = asyncio.Event()
-        asyncio.create_task(prune_widgets_task(removed_widgets, finished_event))
+        create_task(
+            prune_widgets_task(removed_widgets, finished_event), name="prune nodes"
+        )
 
         return AwaitRemove(finished_event)
 

src/textual/message_pump.py

@@ -15,6 +15,7 @@ from typing import TYPE_CHECKING, Any, Awaitable, Callable, Iterable
 from weakref import WeakSet
 
 from . import Logger, events, log, messages
+from ._asyncio import create_task
 from ._callback import invoke
 from ._context import NoActiveAppError, active_app
 from ._time import time
@@ -304,7 +305,12 @@ class MessagePump(metaclass=MessagePumpMeta):
     def _start_messages(self) -> None:
         """Start messages task."""
         if self.app._running:
-            self._task = asyncio.create_task(self._process_messages())
+            self._task = create_task(
+                self._process_messages(), name=f"message pump {self}"
+            )
+        else:
+            self._closing = True
+            self._closed = True
 
     async def _process_messages(self) -> None:
         self._running = True

src/textual/timer.py

@@ -7,7 +7,6 @@ Timer objects are created by [set_interval][textual.message_pump.MessagePump.set
 
 from __future__ import annotations
 
-import asyncio
 import weakref
 from asyncio import CancelledError, Event, Task
 from typing import Awaitable, Callable, Union
@@ -15,6 +14,7 @@ from typing import Awaitable, Callable, Union
 from rich.repr import Result, rich_repr
 
 from . import _clock, events
+from ._asyncio import create_task
 from ._callback import invoke
 from ._context import active_app
 from ._time import sleep
@@ -89,7 +89,7 @@ class Timer:
         Returns:
             A Task instance for the timer.
         """
-        self._task = asyncio.create_task(self._run_timer())
+        self._task = create_task(self._run_timer(), name=self.name)
         return self._task
 
     def stop_no_wait(self) -> None:

src/textual/widget.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from asyncio import Lock, wait
 from asyncio import Lock, create_task, wait
 from collections import Counter
 from fractions import Fraction
@@ -35,6 +36,7 @@ from rich.text import Text
 from rich.traceback import Traceback
 
 from . import errors, events, messages
+from ._asyncio import create_task
 from ._animator import DEFAULT_EASING, Animatable, BoundAnimator, EasingFunction
 from ._arrange import DockArrangeResult, arrange
 from ._context import active_app
@@ -93,7 +95,7 @@ class AwaitMount:
         async def await_mount() -> None:
             if self._widgets:
                 aws = [
-                    create_task(widget._mounted_event.wait())
+                    create_task(widget._mounted_event.wait(), name="await mount")
                     for widget in self._widgets
                 ]
                 if aws:

tests/test_freeze.py

@@ -0,0 +1,26 @@
+import pytest
+
+from textual.app import App
+from textual.screen import Screen
+from textual.widgets import Footer, Header, Input
+
+
+class MyScreen(Screen):
+    def compose(self):
+        yield Header()
+        yield Input()
+        yield Footer()
+
+
+class MyApp(App):
+    def on_mount(self):
+        self.install_screen(MyScreen(), "myscreen")
+        self.push_screen("myscreen")
+
+
+async def test_freeze():
+    """Regression test for https://github.com/Textualize/textual/issues/1608"""
+    app = MyApp()
+    with pytest.raises(Exception):
+        async with app.run_test():
+            raise Exception("never raised")