test: cleanup redundant mock setups in test_async_multi_range_downloader.py

Author: zhixiangli

packages/google-cloud-storage/tests/unit/asyncio/test_async_multi_range_downloader.py

@@ -60,9 +60,6 @@ async def _make_mock_mrd(
         mock_stream.generation_number = _TEST_GENERATION_NUMBER
         mock_stream.persisted_size = _TEST_OBJECT_SIZE
         mock_stream.read_handle = _TEST_READ_HANDLE
-        mock_stream.is_stream_open = True
-        # Default recv blocks forever (tests override with specific side_effect)
-        mock_stream.recv = AsyncMock(side_effect=asyncio.Event().wait)
 
         mrd = await AsyncMultiRangeDownloader.create_mrd(
             mock_client, bucket_name, object_name, generation, read_handle
@@ -422,8 +419,6 @@ async def test_create_mrd_with_generation_number(
         mock_stream.generation_number = _TEST_GENERATION_NUMBER
         mock_stream.persisted_size = _TEST_OBJECT_SIZE
         mock_stream.read_handle = _TEST_READ_HANDLE
-        mock_stream.is_stream_open = True
-        mock_stream.recv = AsyncMock(side_effect=asyncio.Event().wait)
 
         # Act
         mrd = await AsyncMultiRangeDownloader.create_mrd(
@@ -561,7 +556,6 @@ async def staged_recv():
             return None
 
         mock_mrd.read_obj_str.recv = AsyncMock(side_effect=staged_recv)
-        mock_mrd.read_obj_str.is_stream_open = True
 
         mock_random_int.return_value = 123