fix: allow covariance in ZDType

Author: ilan-gold

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

@@ -86,7 +86,7 @@ def to_native_dtype(self) -> DType:
         """
 
         byte_order = endianness_to_numpy_str(self.endianness)
-        return self.dtype_cls().newbyteorder(byte_order)  # type: ignore[return-value]
+        return self.dtype_cls().newbyteorder(byte_order)  # type: ignore[no-any-return,call-overload]
 
     @classmethod
     def _check_json_v2(cls, data: DTypeJSON) -> TypeGuard[DTypeConfig_V2[str, None]]:

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

@@ -74,7 +74,7 @@ def to_native_dtype(self) -> DType:
             The NumPy data type.
         """
         byte_order = endianness_to_numpy_str(self.endianness)
-        return self.dtype_cls().newbyteorder(byte_order)  # type: ignore[return-value]
+        return self.dtype_cls().newbyteorder(byte_order)  # type: ignore[no-any-return,call-overload]
 
     @classmethod
     def _check_json_v2(cls, data: DTypeJSON) -> TypeGuard[DTypeConfig_V2[str, None]]:

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

@@ -740,7 +740,7 @@ class VariableLengthUTF8(UTF8Base[np.dtypes.StringDType]):  # type: ignore[type-
             The object codec ID for this data type.
         """
 
-        dtype_cls = np.dtypes.StringDType
+        dtype_cls = np.dtypes.StringDType  # type: ignore[assignment]
 
         def to_native_dtype(self) -> np.dtypes.StringDType:
             """

src/zarr/core/dtype/wrapper.py

@@ -70,7 +70,7 @@ class variable, and it should generally be unique across different data types.
     """
 
     # this class will create a native data type
-    dtype_cls: ClassVar[type[DType]]
+    dtype_cls: ClassVar[type[TBaseDType]]
     _zarr_v3_name: ClassVar[str]
 
     @classmethod