more v3 unstable dtype warnings, and their exemptions from tests

Author: d-v-b

src/zarr/core/dtype/common.py

@@ -77,9 +77,9 @@ def v3_unstable_dtype_warning(dtype: object) -> None:
     """
     msg = (
         f"The data type ({dtype}) does not have a Zarr V3 specification. "
-        "That means that the representation of data saved with this data type may change without "
+        "That means that the representation of array saved with this data type may change without "
         "warning in a future version of Zarr Python. "
-        "Arrays stored with this data type may be unreadable by other Zarr libraries "
+        "Arrays stored with this data type may be unreadable by other Zarr libraries. "
         "Use this data type at your own risk! "
         "Check https://github.com/zarr-developers/zarr-extensions/tree/main/data-types for the "
         "status of data type specifications for Zarr V3."

src/zarr/core/dtype/npy/bytes.py

@@ -154,6 +154,7 @@ def to_json(self, zarr_format: ZarrFormat) -> str | RawBytesJSONV3:
         if zarr_format == 2:
             return self.to_native_dtype().str
         elif zarr_format == 3:
+            v3_unstable_dtype_warning(self)
             return {"name": self._zarr_v3_name, "configuration": {"length_bytes": self.length}}
         raise ValueError(f"zarr_format must be 2 or 3, got {zarr_format}")  # pragma: no cover
 

src/zarr/core/dtype/npy/string.py

@@ -259,6 +259,7 @@ def to_json(self, zarr_format: ZarrFormat) -> Literal["|O", "variable_length_utf
             if zarr_format == 2:
                 return "|O"
             elif zarr_format == 3:
+                v3_unstable_dtype_warning(self)
                 return self._zarr_v3_name
             raise ValueError(f"zarr_format must be 2 or 3, got {zarr_format}")  # pragma: no cover
 

tests/test_array.py

@@ -1300,6 +1300,7 @@ async def test_v2_chunk_encoding(
 
     @staticmethod
     @pytest.mark.parametrize("dtype", [UInt8(), Float32(), VariableLengthUTF8()])
+    @pytest.mark.filterwarnings("ignore::zarr.core.dtype.common.UnstableSpecificationWarning")
     async def test_default_filters_compressors(
         store: MemoryStore, dtype: UInt8 | Float32 | VariableLengthUTF8, zarr_format: ZarrFormat
     ) -> None:

tests/test_config.py

@@ -306,6 +306,7 @@ class NewCodec2(BytesCodec):
 
 
 @pytest.mark.parametrize("dtype_category", ["variable-length-string", "default"])
+@pytest.mark.filterwarnings("ignore::zarr.core.dtype.common.UnstableSpecificationWarning")
 async def test_default_codecs(dtype_category: str) -> None:
     """
     Test that the default compressors are sensitive to the current setting of the config.

tests/test_dtype/test_npy/test_bytes.py

@@ -1,6 +1,8 @@
 import numpy as np
+import pytest
 
 from tests.test_dtype.test_wrapper import BaseTestZDType, V2JsonTestParams
+from zarr.core.dtype.common import UnstableSpecificationWarning
 from zarr.core.dtype.npy.bytes import NullTerminatedBytes, RawBytes, VariableLengthBytes
 
 
@@ -136,3 +138,17 @@ class TestVariableLengthBytes(BaseTestZDType):
         VariableLengthBytes(),
         VariableLengthBytes(),
     )
+
+
+@pytest.mark.parametrize(
+    "zdtype", [NullTerminatedBytes(length=10), RawBytes(length=10), VariableLengthBytes()]
+)
+def test_unstable_dtype_warning(
+    zdtype: NullTerminatedBytes | RawBytes | VariableLengthBytes,
+) -> None:
+    """
+    Test that we get a warning when serializing a dtype without a zarr v3 spec to json
+    when zarr_format is 3
+    """
+    with pytest.raises(UnstableSpecificationWarning):
+        zdtype.to_json(zarr_format=3)

tests/test_dtype/test_npy/test_string.py

@@ -1,9 +1,11 @@
 from __future__ import annotations
 
 import numpy as np
+import pytest
 
 from tests.test_dtype.test_wrapper import BaseTestZDType, V2JsonTestParams
 from zarr.core.dtype import FixedLengthUTF32
+from zarr.core.dtype.common import UnstableSpecificationWarning
 from zarr.core.dtype.npy.string import _NUMPY_SUPPORTS_VLEN_STRING, VariableLengthUTF8
 
 if _NUMPY_SUPPORTS_VLEN_STRING:
@@ -113,3 +115,13 @@ class TestFixedLengthUTF32(BaseTestZDType):
         FixedLengthUTF32(length=4),
         FixedLengthUTF32(length=10),
     )
+
+
+@pytest.mark.parametrize("zdtype", [FixedLengthUTF32(length=10), VariableLengthUTF8()])
+def test_unstable_dtype_warning(zdtype: FixedLengthUTF32 | VariableLengthUTF8) -> None:
+    """
+    Test that we get a warning when serializing a dtype without a zarr v3 spec to json
+    when zarr_format is 3
+    """
+    with pytest.raises(UnstableSpecificationWarning):
+        zdtype.to_json(zarr_format=3)

tests/test_store/test_stateful.py

@@ -15,6 +15,7 @@
 ]
 
 
+@pytest.mark.filterwarnings("ignore::zarr.core.dtype.common.UnstableSpecificationWarning")
 def test_zarr_hierarchy(sync_store: Store):
     def mk_test_instance_sync() -> ZarrHierarchyStateMachine:
         return ZarrHierarchyStateMachine(sync_store)