Use strict type hinting for namedarray

pyproject.toml

@@ -93,6 +93,7 @@ module = [
   "cftime.*",
   "cubed.*",
   "cupy.*",
+  "dask.types.*",
   "fsspec.*",
   "h5netcdf.*",
   "h5py.*",
@@ -162,6 +163,41 @@ module = [
   "xarray.tests.test_weighted",
 ]
 
+# Use strict = true whenever namedarray has become standalone. In the meantime
+# don't forget to add all new files related to namedarray here:
+# ref: https://mypy.readthedocs.io/en/stable/existing_code.html#introduce-stricter-options
+[[tool.mypy.overrides]]
+# Start off with these
+warn_unused_configs = true
+warn_redundant_casts = true
+warn_unused_ignores = true
+
+# Getting these passing should be easy
+strict_equality = true
+strict_concatenate = true
+
+# Strongly recommend enabling this one as soon as you can
+check_untyped_defs = true
+
+# These shouldn't be too much additional work, but may be tricky to
+# get passing if you use a lot of untyped libraries
+disallow_subclassing_any = true
+disallow_untyped_decorators = true
+disallow_any_generics = true
+
+# These next few are various gradations of forcing use of type annotations
+disallow_untyped_calls = true
+disallow_incomplete_defs = true
+disallow_untyped_defs = true
+
+# This one isn't too hard to get passing, but return on investment is lower
+no_implicit_reexport = true
+
+# This one can be tricky to get passing if you use a lot of untyped libraries
+warn_return_any = true
+
+module = ["xarray.namedarray.*", "xarray.tests.test_namedarray"]
+
 [tool.ruff]
 builtins = ["ellipsis"]
 exclude = [

xarray/core/parallel.py

@@ -443,7 +443,7 @@ def subset_dataset_to_block(
                 for dim in variable.dims:
                     chunk = chunk[chunk_index[dim]]
 
-                chunk_variable_task = (f"{name}-{gname}-{chunk[0]}",) + chunk_tuple
+                chunk_variable_task = (f"{name}-{gname}-{chunk[0]!r}",) + chunk_tuple
                 graph[chunk_variable_task] = (
                     tuple,
                     [variable.dims, chunk, variable.attrs],