Ensure absolute paths work with consolidate metadata (#3428)

* Ensure absolute paths work with consolidate metadata

* bug fix note

* ruff format

Author: shoyer

changes/3428.bugfix.rst

@@ -0,0 +1 @@
+Ensure syntax like ``root['/subgroup']`` works equivalently to ``root['subgroup']`` when using consolidated metadata.

src/zarr/core/group.py

@@ -735,7 +735,7 @@ def _getitem_consolidated(
         assert self.metadata.consolidated_metadata is not None
 
         # we support nested getitems like group/subgroup/array
-        indexers = key.split("/")
+        indexers = normalize_path(key).split("/")
         indexers.reverse()
         metadata: ArrayV2Metadata | ArrayV3Metadata | GroupMetadata = self.metadata
 

tests/test_metadata/test_consolidated.py

@@ -692,6 +692,21 @@ async def test_use_consolidated_for_children_members(
         expected = ["b", "b/c"]
         assert result == expected
 
+    async def test_absolute_path_for_subgroup(self, memory_store: zarr.storage.MemoryStore) -> None:
+        root = await zarr.api.asynchronous.create_group(store=memory_store)
+        await root.create_group("a/b")
+        with pytest.warns(
+            ZarrUserWarning,
+            match="Consolidated metadata is currently not part in the Zarr format 3 specification.",
+        ):
+            await zarr.api.asynchronous.consolidate_metadata(memory_store)
+
+        group = await zarr.api.asynchronous.open_group(store=memory_store)
+        subgroup = await group.getitem("/a")
+        assert isinstance(subgroup, AsyncGroup)
+        members = [x async for x in subgroup.keys()]  # noqa: SIM118
+        assert members == ["b"]
+
 
 @pytest.mark.parametrize("fill_value", [np.nan, np.inf, -np.inf])
 async def test_consolidated_metadata_encodes_special_chars(