Fix some typing

xarray/backends/zarr.py

@@ -768,7 +768,7 @@ def __init__(
             self._members = self._fetch_members()
 
     @property
-    def members(self) -> dict[str, ZarrArray]:
+    def members(self) -> dict[str, ZarrArray | ZarrGroup]:
         """
         Model the arrays and groups contained in self.zarr_group as a dict. If `self._cache_members`
         is true, the dict is cached. Otherwise, it is retrieved from storage.
@@ -778,7 +778,7 @@ def members(self) -> dict[str, ZarrArray]:
         else:
             return self._members
 
-    def _fetch_members(self) -> dict[str, ZarrArray]:
+    def _fetch_members(self) -> dict[str, ZarrArray | ZarrGroup]:
         """
         Get the arrays and groups defined in the zarr group modelled by this Store
         """
@@ -1066,6 +1066,8 @@ def _open_existing_array(self, *, name) -> ZarrArray:
         else:
             zarr_array = self.zarr_group[name]
 
+        if TYPE_CHECKING:
+            assert isinstance(zarr_array, ZarrArray)
         return zarr_array
 
     def _create_new_array(

xarray/core/types.py

@@ -71,7 +71,7 @@
     try:
         from zarr import Array as ZarrArray
     except ImportError:
-        ZarrArray = np.ndarray
+        ZarrArray = np.ndarray  # type: ignore[misc, assignment, unused-ignore]
 
     # Anything that can be coerced to a shape tuple
     _ShapeLike = Union[SupportsIndex, Sequence[SupportsIndex]]