chore: import upstream snapshot with attribution

python/tests/resource/object_storage/test_s3_stream.py

@@ -0,0 +1,98 @@
+# ========= Copyright 2026 @ Strukto.AI All Rights Reserved. =========
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ========= Copyright 2026 @ Strukto.AI All Rights Reserved. =========
+
+import asyncio
+from io import BytesIO
+from unittest.mock import AsyncMock, MagicMock, patch
+
+from mirage.accessor.s3 import S3Accessor
+from mirage.resource.s3 import S3Config
+
+
+def _config():
+    return S3Accessor(
+        S3Config(
+            bucket="test-bucket",
+            region="us-east-1",
+            aws_access_key_id="fake",
+            aws_secret_access_key="fake",
+        ))
+
+
+def _mock_session(data: bytes, chunk_size: int = 8192):
+    mock_client = AsyncMock()
+    body_mock = AsyncMock()
+    body_mock.read = AsyncMock(return_value=data)
+
+    async def _iter_chunks(size=chunk_size):
+        buf = BytesIO(data)
+        while True:
+            chunk = buf.read(size)
+            if not chunk:
+                break
+            yield chunk
+
+    body_mock.iter_chunks = _iter_chunks
+    mock_client.get_object = AsyncMock(return_value={"Body": body_mock})
+
+    mock_session = MagicMock()
+    ctx = AsyncMock()
+    ctx.__aenter__ = AsyncMock(return_value=mock_client)
+    ctx.__aexit__ = AsyncMock(return_value=False)
+    mock_session.client = MagicMock(return_value=ctx)
+    return mock_session
+
+
+def test_read_stream_returns_async_iterator():
+    from mirage.core.s3.stream import read_stream
+    config = _config()
+    session = _mock_session(b"hello world")
+
+    async def _run():
+        chunks = []
+        async for chunk in read_stream(config, "test.txt"):
+            chunks.append(chunk)
+        return chunks
+
+    with patch("mirage.core.s3.stream.async_session", return_value=session):
+        chunks = asyncio.run(_run())
+    assert b"".join(chunks) == b"hello world"
+
+
+def test_read_stream_yields_chunks():
+    from mirage.core.s3.stream import read_stream
+    config = _config()
+    session = _mock_session(b"a" * 100, chunk_size=30)
+
+    async def _run():
+        chunks = []
+        async for chunk in read_stream(config, "test.txt", chunk_size=30):
+            chunks.append(chunk)
+        return chunks
+
+    with patch("mirage.core.s3.stream.async_session", return_value=session):
+        chunks = asyncio.run(_run())
+    assert b"".join(chunks) == b"a" * 100
+    assert len(chunks) >= 2
+
+
+def test_read_bytes_returns_bytes():
+    from mirage.core.s3.read import read_bytes
+    config = _config()
+    session = _mock_session(b"file content here")
+
+    with patch("mirage.core.s3.read.async_session", return_value=session):
+        result = asyncio.run(read_bytes(config, "test.txt"))
+    assert isinstance(result, bytes)
+    assert result == b"file content here"