check for unexpected zarr metadata keys and codec configuration

Author: brokkoli71

src/zarr/core/common.py

@@ -118,6 +118,8 @@ def parse_named_configuration(
 ) -> tuple[str, JSON | None]:
     if not isinstance(data, dict):
         raise TypeError(f"Expected dict, got {type(data)}")
+    if set(data) - {"name", "configuration"}:
+        raise ValueError(f"Named configuration expects keys 'name' and 'configuration'. Got {list(data.keys())}.")
     if "name" not in data:
         raise ValueError(f"Named configuration does not have a 'name' key. Got {data}.")
     name_parsed = parse_name(data["name"], expected_name)

src/zarr/core/metadata/v3.py

@@ -69,13 +69,16 @@ def parse_codecs(data: object) -> tuple[Codec, ...]:
 
     if not isinstance(data, Iterable):
         raise TypeError(f"Expected iterable, got {type(data)}")
-
+    if isinstance(data, str):
+        data = [data]
     for c in data:
         if isinstance(
             c, ArrayArrayCodec | ArrayBytesCodec | BytesBytesCodec
         ):  # Can't use Codec here because of mypy limitation
             out += (c,)
         else:
+            if isinstance(c, str):
+                c = {"name":c}
             name_parsed, _ = parse_named_configuration(c, require_configuration=False)
             out += (get_codec_class(name_parsed).from_dict(c),)
 
@@ -259,10 +262,14 @@ def __init__(
         attributes: dict[str, JSON] | None,
         dimension_names: Iterable[str] | None,
         storage_transformers: Iterable[dict[str, JSON]] | None = None,
+        **kwargs: dict[str, Any],
     ) -> None:
         """
         Because the class is a frozen dataclass, we set attributes using object.__setattr__
         """
+        if kwargs:
+            raise ValueError(f"Unexpected zarr metadata keys: {list(kwargs.keys())}")
+
         shape_parsed = parse_shapelike(shape)
         data_type_parsed = DataType.parse(data_type)
         chunk_grid_parsed = ChunkGrid.from_dict(chunk_grid)

tests/test_metadata/test_v3.py

@@ -412,6 +412,35 @@ def test_dtypes(dtype_str: str) -> None:
         # return type for vlen types may vary depending on numpy version
         assert dt.byte_count is None
 
+def default_metadata_dict(**kwargs) -> dict[str, Any]:
+    d= {
+        "zarr_format": 3,
+        "node_type": "array",
+        "shape": (1,),
+        "chunk_grid": {"name": "regular", "configuration": {"chunk_shape": (1,)}},
+        "data_type": "float64",
+        "chunk_key_encoding": {"name": "default", "separator": "."},
+        "codecs": [{"name": "bytes"}],
+        "fill_value": 0,
+    }
+    for k,v in kwargs.items():
+        d[k]=v
+    return d
 
 def test_fail_on_invalid_value() -> None:
-    pass
+    ArrayV3Metadata.from_dict(default_metadata_dict())
+    with pytest.raises(ValueError, match=re.escape("Unexpected zarr metadata keys: ['unknown']")):
+        ArrayV3Metadata.from_dict(default_metadata_dict(unknown="value"))
+    with pytest.raises(ValueError, match=re.escape("Named configuration expects keys 'name' and 'configuration'. Got ['name', 'unknown'].")):
+        ArrayV3Metadata.from_dict(default_metadata_dict(codecs=[{"name":"bytes","unknown": "value"}]))
+
+
+def test_string_codecs() -> None:
+    expected = ArrayV3Metadata.from_dict(default_metadata_dict(data_type="bool", codecs=[{"name": "bytes"}]))
+    result1 = ArrayV3Metadata.from_dict(default_metadata_dict(data_type="bool",codecs=["bytes"]))
+    assert result1.codecs == expected.codecs
+    result2 = ArrayV3Metadata.from_dict(default_metadata_dict(data_type="bool",codecs="bytes"))
+    assert result2.codecs == expected.codecs
+    ArrayV3Metadata.from_dict(default_metadata_dict(data_type="int16", codecs=["bytes"]))
+    with pytest.raises(ValueError, match="Expected bytes codec to specify argument endian for data_type=int16"):
+        ArrayV3Metadata.from_dict(default_metadata_dict(data_type="int16", codecs=["bytes"]))