feat(dataset): integrate episode streaming into training

tests/datasets/test_streaming_sidecar_adapter.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python
+
+# Copyright 2026 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
+
+from pathlib import Path
+from types import SimpleNamespace
+
+import pytest
+
+pytest.importorskip("datasets", reason="datasets is required (install lerobot[dataset])")
+
+from lerobot.datasets.streaming_sidecar import range_backend_for_root, streaming_data_root
+
+
+def test_hub_data_root_is_revision_qualified() -> None:
+    meta = SimpleNamespace(repo_id="owner/dataset", revision="commit-sha")
+
+    root = streaming_data_root(meta, requested_root=None, configured_data_root=None)
+
+    assert root == "hf://datasets/owner/dataset@commit-sha"
+    assert range_backend_for_root(root) == "native-http"
+
+
+def test_explicit_bucket_root_is_preserved() -> None:
+    meta = SimpleNamespace(repo_id="owner/dataset", revision="commit-sha")
+    bucket = "hf://buckets/owner/dataset-bucket/prefix/"
+
+    root = streaming_data_root(meta, requested_root=None, configured_data_root=bucket)
+
+    assert root == bucket.rstrip("/")
+    assert range_backend_for_root(root) == "native-http"
+
+
+def test_local_and_generic_remote_roots_use_fsspec(tmp_path: Path) -> None:
+    meta = SimpleNamespace(repo_id="owner/dataset", revision="commit-sha")
+
+    local = streaming_data_root(meta, requested_root=tmp_path, configured_data_root=None)
+
+    assert local == str(tmp_path)
+    assert range_backend_for_root(local) == "fsspec"
+    assert range_backend_for_root("memory://dataset") == "fsspec"