chore: import upstream snapshot with attribution

backend/tests/data/test_get_data_layer.py

@@ -0,0 +1,18 @@
+from unittest.mock import AsyncMock, Mock
+
+from chainlit.data import get_data_layer
+
+
+async def test_get_data_layer(
+    mock_data_layer: AsyncMock,
+    mock_get_data_layer: Mock,
+):
+    # Check whether the data layer is properly set
+    assert mock_data_layer == get_data_layer()
+
+    mock_get_data_layer.assert_called_once()
+
+    # Getting the data layer again, should not result in additional call
+    assert mock_data_layer == get_data_layer()
+
+    mock_get_data_layer.assert_called_once()