Apply suggestions from code review

Co-authored-by: Bruno Oliveira <[email protected]>

Author: amezin

changelog/1144.feature

@@ -1 +1,3 @@
-Make "steal" command atomic - make it unschedule either all requested tests or none.
+The internal `steal` command is now atomic - make it unschedule either all requested tests or none.
+
+This is a prerequisite for group/scope support in the `worksteal` scheduler, so tests won't be broken up incorrectly.

src/xdist/remote.py

@@ -72,7 +72,7 @@ class Marker(enum.Enum):
 
 
 class TestQueue:
-    """A simple queue that can be inspected and modified while the lock is held."""
+    """A simple queue that can be inspected and modified while the lock is held via the ``lock()`` method."""
 
     Item = Union[int, Literal[Marker.SHUTDOWN]]
 

testing/test_remote.py

@@ -267,8 +267,10 @@ def test_func4(): pass
 
         worker.sendcommand("steal", indices=[1, 2])
         ev = worker.popevent("unscheduled")
+        # Cannot steal index 1 because it is completed already, so do not steal any. 
         assert ev.kwargs["indices"] == []
 
+        # Index 2 can be stolen, as it is still pending.
         worker.sendcommand("steal", indices=[2])
         ev = worker.popevent("unscheduled")
         assert ev.kwargs["indices"] == [2]