timeouts: don't cancel on timeout during a debugging session

Fixes #16

Author: delfick

README.rst

@@ -21,6 +21,9 @@ generator fixtures.
 Changelog
 ---------
 
+0.7.2 - TBD
+    * Timeouts don't take affect if the debugger is active
+
 0.7.1 - 23 June 2023
     * No functional changes, only fixing how hatchling understands the
       license field in the pyproject.toml with thanks to @piotrm-nvidia
@@ -159,6 +162,10 @@ The default timeout is 5 seconds. You can change this default by setting the
 This setting is also available from the CLI using the ``--default-async-timeout``
 option.
 
+Note that if the timeout fires whilst you have the debugger active then the timeout
+will not cancel the current test. This is determined by checking if ``sys.gettrace()``
+returns a non-None value.
+
 Overriding the loop
 -------------------
 

alt_pytest_asyncio/async_converters.py

@@ -233,8 +233,13 @@ async def async_runner(func, timeout, info, args, kwargs):
 
     def timeout_task(task):
         if not task.done():
-            info["cancelled"] = True
-            task.cancel()
+            # If the debugger is active then don't cancel, so that debugging may continue
+            # sys.gettrace is not a language feature and notguaranteed to be available
+            # on all python implementations, so we see if it exists
+            gettrace = getattr(sys, "gettrace", None)
+            if gettrace is None or gettrace() is None:
+                info["cancelled"] = True
+                task.cancel()
 
     asyncio.get_event_loop().call_later(timeout, timeout_task, current_task)