Check untyped defs on v3

pyproject.toml

@@ -148,7 +148,7 @@ extend-exclude = [
 ]
 
 [tool.mypy]
-python_version = "3.8"
+python_version = "3.10"
 ignore_missing_imports = true
 namespace_packages = false
 
@@ -157,6 +157,24 @@ warn_redundant_casts = true
 warn_unused_ignores = true
 
 
+check_untyped_defs = true
+
+[[tool.mypy.overrides]]
+module = [
+    "zarr._storage.store",
+    "zarr._storage.v3_storage_transformers",
+    "zarr.v3.group",
+    "zarr.core",
+    "zarr.hierarchy",
+    "zarr.indexing",
+    "zarr.storage",
+    "zarr.sync",
+    "zarr.util",
+    "tests.*",
+]
+check_untyped_defs = false
+
+
 [tool.pytest.ini_options]
 doctest_optionflags = [
     "NORMALIZE_WHITESPACE",

src/zarr/attrs.py

@@ -1,3 +1,4 @@
+from typing import Any
 import warnings
 from collections.abc import MutableMapping
 
@@ -39,7 +40,7 @@ def _get_nosync(self):
         try:
             data = self.store[self.key]
         except KeyError:
-            d = dict()
+            d: dict[str, Any] = dict()
             if self._version > 2:
                 d["attributes"] = {}
         else:

src/zarr/n5.py

@@ -325,10 +325,9 @@ class N5FSStore(FSStore):
 
     def __init__(self, *args, **kwargs):
         if "dimension_separator" in kwargs:
-            kwargs.pop("dimension_separator")
             warnings.warn("Keyword argument `dimension_separator` will be ignored")
-        dimension_separator = "."
-        super().__init__(*args, dimension_separator=dimension_separator, **kwargs)
+        kwargs["dimension_separator"] = "."
+        super().__init__(*args, **kwargs)
 
     @staticmethod
     def _swap_separator(key: str):

src/zarr/v3/sync.py

@@ -90,8 +90,9 @@ def _get_loop():
             # repeat the check just in case the loop got filled between the
             # previous two calls from another thread
             if loop[0] is None:
-                loop[0] = asyncio.new_event_loop()
-                th = threading.Thread(target=loop[0].run_forever, name="zarrIO")
+                new_loop = asyncio.new_event_loop()
+                loop[0] = new_loop
+                th = threading.Thread(target=new_loop.run_forever, name="zarrIO")
                 th.daemon = True
                 th.start()
                 iothread[0] = th