Fixed repr of MemoryObjectItemReceiver

docs/versionhistory.rst

@@ -5,6 +5,8 @@ This library adheres to `Semantic Versioning 2.0 <http://semver.org/>`_.
 
 **UNRELEASED**
 
+- Fixed ``__repr__()`` of ``MemoryObjectItemReceiver``, when ``item`` is not defined
+  (`#767 <https://github.com/agronholm/anyio/pulls/767>`_; PR by @Danipulok)
 - Added support for the ``from_uri()``, ``full_match()``, ``parser`` methods/properties
   in ``anyio.Path``, newly added in Python 3.13
   (`#737 <https://github.com/agronholm/anyio/issues/737>`_)

src/anyio/streams/memory.py

@@ -38,6 +38,12 @@ class MemoryObjectItemReceiver(Generic[T_Item]):
     task_info: TaskInfo = field(init=False, default_factory=get_current_task)
     item: T_Item = field(init=False)
 
+    def __repr__(self) -> str:
+        # When item is not defined, we get following error with default __repr__:
+        # AttributeError: 'MemoryObjectItemReceiver' object has no attribute 'item'
+        item = getattr(self, "item", None)
+        return f"{self.__class__.__name__}(task_info={self.task_info}, item={item!r})"
+
 
 @dataclass(eq=False)
 class MemoryObjectStreamState(Generic[T_Item]):

tests/streams/test_memory.py

@@ -18,7 +18,11 @@
     wait_all_tasks_blocked,
 )
 from anyio.abc import ObjectReceiveStream, ObjectSendStream, TaskStatus
-from anyio.streams.memory import MemoryObjectReceiveStream, MemoryObjectSendStream
+from anyio.streams.memory import (
+    MemoryObjectItemReceiver,
+    MemoryObjectReceiveStream,
+    MemoryObjectSendStream,
+)
 
 if sys.version_info < (3, 11):
     from exceptiongroup import ExceptionGroup
@@ -502,3 +506,20 @@ async def test_send_to_natively_cancelled_receiver() -> None:
             await receive_task
 
         assert receive.receive_nowait() == "hello"
+
+
+async def test_memory_object_item_receiver_repr() -> None:
+    """
+    Test the repr of `MemoryObjectItemReceiver`.
+    Since when `item` is not set, the default dataclass repr raises an AttributeError.
+    """
+    receiver = MemoryObjectItemReceiver[str]()
+
+    assert str(receiver) is not None
+    receiver_repr = repr(receiver)
+    assert "item=None" in receiver_repr
+
+    assert str(receiver) is not None
+    receiver.item = "test_item"
+    receiver_repr = repr(receiver)
+    assert "item='test_item'" in receiver_repr