add unit tests and idomatic

Author: chandra-siri

google/cloud/storage/_experimental/asyncio/async_appendable_object_writer.py

@@ -137,9 +137,9 @@ def __init__(
             raise exceptions.OutOfRange(
                 f"flush_interval must be >= {_MAX_CHUNK_SIZE_BYTES} , but provided {self.flush_interval}"
             )
-        if not self.flush_interval % _MAX_CHUNK_SIZE_BYTES == 0:
+        if self.flush_interval % _MAX_CHUNK_SIZE_BYTES != 0:
             raise exceptions.OutOfRange(
-                f"flush interval - {self.flush_interval} should be multiple of  {_MAX_CHUNK_SIZE_BYTES}"
+                f"flush_interval must be a multiple of {_MAX_CHUNK_SIZE_BYTES}, but provided {self.flush_interval}"
             )
         self.bytes_appended_since_last_flush = 0
 
@@ -210,7 +210,6 @@ async def append(self, data: bytes) -> None:
             self.offset = self.persisted_size
 
         start_idx = 0
-        # bytes_to_flush = 0
         while start_idx < total_bytes:
             end_idx = min(start_idx + _MAX_CHUNK_SIZE_BYTES, total_bytes)
             data_chunk = data[start_idx:end_idx]

tests/unit/asyncio/test_async_appendable_object_writer.py

@@ -19,6 +19,9 @@
 from google.cloud.storage._experimental.asyncio.async_appendable_object_writer import (
     AsyncAppendableObjectWriter,
 )
+from google.cloud.storage._experimental.asyncio.async_appendable_object_writer import (
+    _MAX_CHUNK_SIZE_BYTES,
+)
 from google.cloud import _storage_v2
 
 
@@ -113,6 +116,36 @@ def test_init_with_writer_options(mock_write_object_stream, mock_client):
     )
 
 
+@mock.patch(
+    "google.cloud.storage._experimental.asyncio.async_appendable_object_writer._AsyncWriteObjectStream"
+)
+def test_init_with_flush_interval_less_than_chunk_size_raises_error(mock_client):
+    """Test that an OutOfRange error is raised if flush_interval is less than the chunk size."""
+
+    with pytest.raises(exceptions.OutOfRange):
+        AsyncAppendableObjectWriter(
+            mock_client,
+            BUCKET,
+            OBJECT,
+            writer_options={"FLUSH_INTERVAL_BYTES": _MAX_CHUNK_SIZE_BYTES - 1},
+        )
+
+
+@mock.patch(
+    "google.cloud.storage._experimental.asyncio.async_appendable_object_writer._AsyncWriteObjectStream"
+)
+def test_init_with_flush_interval_not_multiple_of_chunk_size_raises_error(mock_client):
+    """Test that an OutOfRange error is raised if flush_interval is not a multiple of the chunk size."""
+
+    with pytest.raises(exceptions.OutOfRange):
+        AsyncAppendableObjectWriter(
+            mock_client,
+            BUCKET,
+            OBJECT,
+            writer_options={"FLUSH_INTERVAL_BYTES": _MAX_CHUNK_SIZE_BYTES + 1},
+        )
+
+
 @mock.patch("google.cloud.storage._experimental.asyncio._utils.google_crc32c")
 @mock.patch(
     "google.cloud.storage._experimental.asyncio.async_grpc_client.AsyncGrpcClient.grpc_client"