Replace the stream_method return to AsyncIterable (#87)

This is to match the type of streaming methods generated by `grpc`, so
no conversion to an `AsyncIterator` is needed.

Author: llucax

RELEASE_NOTES.md

@@ -6,7 +6,7 @@
 
 ## Upgrading
 
-<!-- Here goes notes on how to upgrade from previous versions, including deprecations and what they should be replaced with -->
+- `GrpcStreamBroadcaster` now takes a `AsyncIterable` instead of a `AsyncIterator` as the `stream_method`. This is to match the type of streaming methods generated by `grpc`, so no conversion to an `AsyncIterator` is needed.
 
 ## New Features
 

src/frequenz/client/base/streaming.py

@@ -5,8 +5,8 @@
 
 import asyncio
 import logging
-from collections.abc import AsyncIterator, Callable
-from typing import Generic, TypeVar
+from collections.abc import Callable
+from typing import AsyncIterable, Generic, TypeVar
 
 import grpc.aio
 
@@ -30,7 +30,7 @@ class GrpcStreamBroadcaster(Generic[InputT, OutputT]):
     def __init__(
         self,
         stream_name: str,
-        stream_method: Callable[[], AsyncIterator[InputT]],
+        stream_method: Callable[[], AsyncIterable[InputT]],
         transform: Callable[[InputT], OutputT],
         retry_strategy: retry.Strategy | None = None,
     ):