Add new tests for cloud transfer

tests/func/test_cloud_transfer.py

@@ -0,0 +1,41 @@
+import pytest
+
+from datachain.client import Client
+from datachain.lib.dc import DataChain
+
+
+@pytest.mark.parametrize(
+    "src_cloud_type,dst_cloud_type",
+    [
+        ("azure", "gs"),
+        ("gs", "azure"),
+        ("s3", "gs"),
+        ("gs", "s3"),
+    ],
+    indirect=["src_cloud_type"],
+)
+def test_cross_cloud_transfer(
+    cloud_test_catalog_upload,
+    cloud_type,
+    src_cloud_type,
+    dst_cloud_type,
+    tmp_upath_factory,
+):
+    # Setup source and destination paths
+    src_path = tmp_upath_factory.mktemp(src_cloud_type)
+    dst_path = tmp_upath_factory.mktemp(dst_cloud_type)
+
+    # Create test file in source
+    test_content = b"test content"
+    (src_path / "test.txt").write_bytes(test_content)
+
+    # Create DataChain and transfer
+    ds = DataChain.from_storage(f"{src_cloud_type}://{src_path}/test.txt")
+    ds.to_storage(f"{dst_cloud_type}://{dst_path}/destination", placement="filename")
+
+    # Verify transfer
+    dst_client = Client.get_client(f"{dst_cloud_type}://{dst_path}", None)
+    assert dst_client.fs.exists(f"{dst_path}/destination/test.txt")
+
+    transferred_content = dst_client.fs.read_bytes(f"{dst_path}/destination/test.txt")
+    assert transferred_content == test_content