chore: import upstream snapshot with attribution

tests/utils/test_visualization_utils.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+
+# Copyright 2025 The HuggingFace Inc. team. 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.
+
+"""Tests for the backend-agnostic visualization dispatch.
+
+These exercise the display-mode routing/validation only; they need neither ``rerun`` nor
+``foxglove`` installed since the unknown-mode branch raises before touching any backend. Backend
+behavior is covered in ``test_rerun_visualization.py`` and ``test_foxglove_visualization.py``.
+"""
+
+import pytest
+
+from lerobot.utils import visualization_utils as vu
+
+
+def test_visualization_modes():
+    assert vu.VISUALIZATION_MODES == ("rerun", "foxglove")
+
+
+@pytest.mark.parametrize("func", ["init_visualization", "log_visualization_data", "shutdown_visualization"])
+def test_dispatch_rejects_unknown_mode(func):
+    with pytest.raises(ValueError, match="Unknown display_mode"):
+        getattr(vu, func)("bogus")