robuster

src/zarr/api/asynchronous.py

@@ -14,6 +14,7 @@
 from zarr.core.group import AsyncGroup
 from zarr.core.metadata.v2 import ArrayV2Metadata
 from zarr.core.metadata.v3 import ArrayV3Metadata
+from zarr.errors import NodeTypeValidationError
 from zarr.storage import (
     StoreLike,
     StorePath,
@@ -247,9 +248,9 @@ async def open(
 
     try:
         return await open_array(store=store_path, zarr_format=zarr_format, **kwargs)
-    except (KeyError, ValueError):
+    except (KeyError, NodeTypeValidationError):
         # KeyError for a missing key
-        # ValueError for failing to parse node metadata as an array when it's
+        # NodeTypeValidationError for failing to parse node metadata as an array when it's
         # actually a group
         return await open_group(store=store_path, zarr_format=zarr_format, **kwargs)
 

src/zarr/core/metadata/v3.py

@@ -28,6 +28,7 @@
 from zarr.core.common import ZARR_JSON, parse_named_configuration, parse_shapelike
 from zarr.core.config import config
 from zarr.core.metadata.common import ArrayMetadata, parse_attributes
+from zarr.errors import MetadataValidationError, NodeTypeValidationError
 from zarr.registry import get_codec_class
 
 DEFAULT_DTYPE = "float64"
@@ -36,13 +37,13 @@
 def parse_zarr_format(data: object) -> Literal[3]:
     if data == 3:
         return 3
-    raise ValueError(f"Invalid value. Expected 3. Got {data}.")
+    raise MetadataValidationError(f"Invalid value. Expected 3. Got {data}.")
 
 
 def parse_node_type_array(data: object) -> Literal["array"]:
     if data == "array":
         return "array"
-    raise ValueError(f"Invalid value. Expected 'array'. Got {data}.")
+    raise NodeTypeValidationError(f"Invalid value. Expected 'array'. Got {data}.")
 
 
 def parse_codecs(data: object) -> tuple[Codec, ...]:

src/zarr/errors.py

@@ -25,6 +25,19 @@ class ContainsArrayAndGroupError(_BaseZarrError):
     )
 
 
+class MetadataValidationError(_BaseZarrError):
+    """An exception raised when the Zarr metadata is invalid in some way"""
+
+
+class NodeTypeValidationError(MetadataValidationError):
+    """
+    Specialized exception when the node_type of the metadata document is incorrect..
+
+    This can be raised when the value is invalid or unexpected given the context,
+    for example an 'array' node when we expected a 'group'.
+    """
+
+
 __all__ = [
     "ContainsArrayAndGroupError",
     "ContainsArrayError",