googleapis · chandra-siri · Dec 19, 2025 · Dec 18, 2025 · Dec 18, 2025 · Dec 18, 2025
@@ -5,6 +5,8 @@
 from io import BytesIO
 
 # python additional imports
+import google_crc32c
+
 import pytest
 
 # current library imports
@@ -28,6 +30,11 @@
 _BYTES_TO_UPLOAD = b"dummy_bytes_to_write_read_and_delete_appendable_object"
 
 
+def _get_equal_dist(a: int, b: int) -> tuple[int, int]:
+    step = (b - a) // 3
+    return a + step, a + 2 * step
+
+
 async def write_one_appendable_object(
     bucket_name: str,
     object_name: str,
@@ -59,11 +66,21 @@ def appendable_object(storage_client, blobs_to_delete):
 
 
 @pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "object_size",
+    [
+        256,  # less than _chunk size
+        10 * 1024 * 1024,  # less than _MAX_BUFFER_SIZE_BYTES
+        20 * 1024 * 1024,  # greater than _MAX_BUFFER_SIZE
+    ],
+)
 @pytest.mark.parametrize(
     "attempt_direct_path",
     [True, False],
 )
-async def test_basic_wrd(storage_client, blobs_to_delete, attempt_direct_path):
+async def test_basic_wrd(
+    storage_client, blobs_to_delete, attempt_direct_path, object_size
+):
     object_name = f"test_basic_wrd-{str(uuid.uuid4())}"
 
     # Client instantiation; it cannot be part of fixture because.
@@ -74,22 +91,72 @@ async def test_basic_wrd(storage_client, blobs_to_delete, attempt_direct_path):
     # 2. we can keep the same event loop for entire module but that may
     #  create issues if tests are run in parallel and one test hogs the event
     #  loop slowing down other tests.
+    object_data = os.urandom(object_size)
+    object_checksum = google_crc32c.value(object_data)
     grpc_client = AsyncGrpcClient(attempt_direct_path=attempt_direct_path).grpc_client
 
     writer = AsyncAppendableObjectWriter(grpc_client, _ZONAL_BUCKET, object_name)
     await writer.open()
-    await writer.append(_BYTES_TO_UPLOAD)
+    await writer.append(object_data)
     object_metadata = await writer.close(finalize_on_close=True)
-    assert object_metadata.size == len(_BYTES_TO_UPLOAD)
+    assert object_metadata.size == object_size
+    assert int(object_metadata.checksums.crc32c) == object_checksum
 
     mrd = AsyncMultiRangeDownloader(grpc_client, _ZONAL_BUCKET, object_name)
     buffer = BytesIO()
     await mrd.open()
     # (0, 0) means read the whole object
     await mrd.download_ranges([(0, 0, buffer)])
     await mrd.close()
-    assert buffer.getvalue() == _BYTES_TO_UPLOAD
-    assert mrd.persisted_size == len(_BYTES_TO_UPLOAD)
+    assert buffer.getvalue() == object_data
+    assert mrd.persisted_size == object_size
+
+    # Clean up; use json client (i.e. `storage_client` fixture) to delete.
+    blobs_to_delete.append(storage_client.bucket(_ZONAL_BUCKET).blob(object_name))
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "object_size",
+    [
+        10,  # less than _chunk size,
+        10 * 1024 * 1024,  # less than _MAX_BUFFER_SIZE_BYTES
+        20 * 1024 * 1024,  # greater than _MAX_BUFFER_SIZE_BYTES
+    ],
+)
+async def test_basic_wrd_in_slices(storage_client, blobs_to_delete, object_size):
+    object_name = f"test_basic_wrd-{str(uuid.uuid4())}"
+
+    # Client instantiation; it cannot be part of fixture because.
+    # grpc_client's event loop and event loop of coroutine running it
+    # (i.e. this test) must be same.
+    # Note:
+    # 1. @pytest.mark.asyncio ensures new event loop for each test.
+    # 2. we can keep the same event loop for entire module but that may
+    #  create issues if tests are run in parallel and one test hogs the event
+    #  loop slowing down other tests.
+    object_data = os.urandom(object_size)
+    object_checksum = google_crc32c.value(object_data)
+    grpc_client = AsyncGrpcClient().grpc_client
+
+    writer = AsyncAppendableObjectWriter(grpc_client, _ZONAL_BUCKET, object_name)
+    await writer.open()
+    mark1, mark2 = _get_equal_dist(0, object_size)
+    await writer.append(object_data[0:mark1])
+    await writer.append(object_data[mark1:mark2])
+    await writer.append(object_data[mark2:])
+    object_metadata = await writer.close(finalize_on_close=True)
+    assert object_metadata.size == object_size
+    assert int(object_metadata.checksums.crc32c) == object_checksum
+
+    mrd = AsyncMultiRangeDownloader(grpc_client, _ZONAL_BUCKET, object_name)
+    buffer = BytesIO()
+    await mrd.open()
+    # (0, 0) means read the whole object
+    await mrd.download_ranges([(0, 0, buffer)])
+    await mrd.close()
+    assert buffer.getvalue() == object_data
+    assert mrd.persisted_size == object_size
 
     # Clean up; use json client (i.e. `storage_client` fixture) to delete.
     blobs_to_delete.append(storage_client.bucket(_ZONAL_BUCKET).blob(object_name))