Add more debugging statements

shiny/session/_session.py

@@ -242,7 +242,9 @@ async def _run_session_end_tasks(self) -> None:
         self._has_run_session_end_tasks = True
 
         try:
+            print(f"Invoking {self._on_ended_callbacks.count()} on ended callbacks")
             await self._on_ended_callbacks.invoke()
+            print("After invoking on ended callbacks")
         finally:
             self.app._remove_session(self)
 
@@ -773,6 +775,7 @@ def on_ended(
         :
             A function that can be used to cancel the registration.
         """
+        print("adding on_ended callback")
         return self._on_ended_callbacks.register(wrap_async(fn))
 
     # ==========================================================================

tests/playwright/conftest.py

@@ -143,6 +143,7 @@ def __init__(self, proc: subprocess.Popen[str], port: int):
 
     def _run(self) -> None:
         self.proc.wait()
+        sleep(0.5)
         if self.proc.stdout is not None:
             self.proc.stdout.close()
         if self.proc.stderr is not None: