fix(storage): remove VerboseModule to make zarr.storage picklable (gh-4029)

src/zarr/storage/__init__.py

@@ -1,9 +1,3 @@
-import sys
-import warnings
-from types import ModuleType
-from typing import Any
-
-from zarr.errors import ZarrDeprecationWarning
 from zarr.storage._common import StoreLike, StorePath
 from zarr.storage._fsspec import FsspecStore
 from zarr.storage._local import LocalStore
@@ -27,18 +21,4 @@
 ]
 
 
-class VerboseModule(ModuleType):
-    def __setattr__(self, attr: str, value: Any) -> None:
-        if attr == "default_compressor":
-            warnings.warn(
-                "setting zarr.storage.default_compressor is deprecated, use "
-                "zarr.config to configure array.v2_default_compressor "
-                "e.g. config.set({'codecs.zstd':'numcodecs.Zstd', 'array.v2_default_compressor.numeric': 'zstd'})",
-                ZarrDeprecationWarning,
-                stacklevel=1,
-            )
-        else:
-            super().__setattr__(attr, value)
-
 
-sys.modules[__name__].__class__ = VerboseModule

tests/test_v2.py

@@ -224,9 +224,18 @@ def test_v2_non_contiguous(numpy_order: Literal["C", "F"], zarr_order: Literal["
         assert (sub_arr).flags.c_contiguous
 
 
-def test_default_compressor_deprecation_warning() -> None:
-    with pytest.warns(ZarrDeprecationWarning, match="default_compressor is deprecated"):
+def test_storage_module_is_picklable() -> None:
+    import pickle
+
+    # regression test for gh-4029
+    assert pickle.dumps(zarr.storage)
+
+
+def test_default_compressor_no_longer_warns() -> None:
+    # VerboseModule removed in gh-4029 to make zarr.storage picklable
+    with pytest.warns() as record:
         zarr.storage.default_compressor = "zarr.codecs.zstd.ZstdCodec()"  # type: ignore[attr-defined]
+    assert not any("default_compressor is deprecated" in str(w.message) for w in record)
 
 
 @pytest.mark.parametrize("fill_value", [None, (b"", 0, 0.0)], ids=["no_fill", "fill"])