docstring

src/textual/_wait.py

@@ -0,0 +1,26 @@
+from asyncio import sleep
+from time import process_time, time
+
+
+SLEEP_GRANULARITY: float = 1 / 50
+SLEEP_IDLE: float = SLEEP_GRANULARITY / 2.0
+
+
+async def wait_for_idle(min_sleep: float = 0.01, max_sleep: float = 1) -> None:
+    """Wait until the cpu isn't working very hard.
+
+    Args:
+        min_sleep: Minimum time to wait. Defaults to 0.01.
+        max_sleep: Maximum time to wait. Defaults to 1.
+    """
+    start_time = time()
+
+    while True:
+        cpu_time = process_time()
+        await sleep(SLEEP_GRANULARITY)
+        cpu_elapsed = process_time() - cpu_time
+        elapsed_time = time() - start_time
+        if elapsed_time >= max_sleep:
+            break
+        if elapsed_time > min_sleep and cpu_elapsed < SLEEP_IDLE:
+            break

src/textual/app.py

@@ -68,6 +68,7 @@ from .messages import CallbackType
 from .reactive import Reactive
 from .renderables.blank import Blank
 from .screen import Screen
+from ._wait import wait_for_idle
 from .widget import AwaitMount, Widget
 
 if TYPE_CHECKING:
@@ -796,11 +797,11 @@ class App(Generic[ReturnType], DOMNode):
         app = self
         driver = app._driver
         assert driver is not None
-        await asyncio.sleep(0.02)
+        # await asyncio.sleep(0.02)
+        await wait_for_idle(0)
         for key in keys:
             if key == "_":
-                print("(pause 50ms)")
+                continue
-                await asyncio.sleep(0.05)
             elif key.startswith("wait:"):
                 _, wait_ms = key.split(":")
                 print(f"(pause {wait_ms}ms)")
@@ -822,13 +823,8 @@ class App(Generic[ReturnType], DOMNode):
                 print(f"press {key!r} (char={char!r})")
                 key_event = events.Key(app, key, char)
                 driver.send_event(key_event)
-                # TODO: A bit of a fudge - extra sleep after tabbing to help guard against race
+                await wait_for_idle(0)
-                #  condition between widget-level key handling and app/screen level handling.
+
-                #  More information here: https://github.com/Textualize/textual/issues/1009
-                #  This conditional sleep can be removed after that issue is closed.
-                if key == "tab":
-                    await asyncio.sleep(0.05)
-                await asyncio.sleep(0.025)
         await app._animator.wait_for_idle()
 
     @asynccontextmanager

src/textual/pilot.py

@@ -6,6 +6,7 @@ import asyncio
 from typing import Generic
 
 from .app import App, ReturnType
+from ._wait import wait_for_idle
 
 
 @rich.repr.auto(angular=True)
@@ -52,4 +53,5 @@ class Pilot(Generic[ReturnType]):
         Args:
             result: The app result returned by `run` or `run_async`.
         """
+        await wait_for_idle()
         self.app.exit(result)

tests/snapshot_tests/test_snapshots.py

@@ -190,6 +190,6 @@ def test_demo(snap_compare):
     """Test the demo app (python -m textual)"""
     assert snap_compare(
         Path("../../src/textual/demo.py"),
-        press=["down", "down", "down", "_", "_", "_"],
+        press=["down", "down", "down"],
         terminal_size=(100, 30),
     )