Tighten up type checking and type annotations (#609)

* Tighten up type checking and type annotations

* Fix type annotation for Python < 3.10

* Loosen overly strict type checking options

mypy.ini

@@ -19,6 +19,14 @@
 
 [mypy]
 files = *.py,pottery/,tests/
+disallow_incomplete_defs = True
+disallow_untyped_calls = True
+disallow_untyped_decorators = True
+disallow_any_unimported = True
+disallow_subclassing_any = True
+warn_unreachable = True
+warn_return_any = True
+warn_redundant_casts = True
 
 
 

pottery/cache.py

@@ -186,7 +186,7 @@ def cache_clear() -> None:
 
 def _set_expiration(func: F) -> F:
     @functools.wraps(func)
-    def wrapper(self, *args: Any, **kwargs: Any) -> Any:
+    def wrapper(self: Any, *args: Any, **kwargs: Any) -> Any:
         value = func(self, *args, **kwargs)
         if self._timeout:
             self._cache.redis.expire(self._cache.key, self._timeout)  # Available since Redis 1.0.0

pottery/list.py

@@ -66,10 +66,10 @@ class RedisList(Base, collections.abc.MutableSequence):
 
     def __slice_to_indices(self, slice_or_index: slice | int) -> range:
         if isinstance(slice_or_index, slice):
-            start, stop, step = cast(slice, slice_or_index).indices(len(self))
+            start, stop, step = slice_or_index.indices(len(self))
         elif isinstance(slice_or_index, int):
-            start = cast(int, slice_or_index)
-            stop = cast(int, slice_or_index) + 1
+            start = slice_or_index
+            stop = slice_or_index + 1
             step = 1
         else:
             raise TypeError(
@@ -146,14 +146,16 @@ def __getitem__(self, index: slice | int) -> Any:
         return value
 
     @_raise_on_error
-    def __setitem__(self, index: int, value: JSONTypes) -> None:  # type: ignore
+    def __setitem__(self, index: slice | int, value: JSONTypes) -> None:  # type: ignore
         'l.__setitem__(index, value) <==> l[index] = value.  O(n)'
         with self._watch() as pipeline:
             if isinstance(index, slice):
                 warnings.warn(
                     cast(str, InefficientAccessWarning.__doc__),
                     InefficientAccessWarning,
                 )
+                if not isinstance(value, Iterable):
+                    raise TypeError('can only assign an iterable')
                 encoded_values = [self._encode(value) for value in value]
                 indices = self.__slice_to_indices(index)
                 pipeline.multi()  # Available since Redis 1.2.0

pottery/monkey.py

@@ -26,6 +26,7 @@
 from typing import Callable
 from typing import Dict
 from typing import List
+from typing import Union
 from typing import cast
 
 # TODO: When we drop support for Python 3.7, change the following import to:
@@ -55,7 +56,7 @@ def _default(self: Any, obj: Any) -> Dict[str, Any] | List[Any] | str:
         )
     method = methods[0] if methods else _default.default  # type: ignore
     return_value = method(obj)  # type: ignore
-    return return_value
+    return cast(Union[Dict[str, Any], List[Any], str], return_value)
 
 import json  # isort: skip
 _default.default = json.JSONEncoder().default  # type: ignore

pottery/set.py

@@ -91,7 +91,7 @@ def contains_many(self, *values: JSONTypes) -> Generator[bool, None, None]:
             encoded_values.append(encoded_value)
 
         # Available since Redis 6.2.0:
-        for is_member in self.redis.smismember(self.key, encoded_values):
+        for is_member in self.redis.smismember(self.key, encoded_values):  # type: ignore
             yield bool(is_member)
 
     def __iter__(self) -> Generator[JSONTypes, None, None]:
@@ -197,7 +197,7 @@ def __set_op(self,
         with self._watch(*others):
             set_ = self.__to_set()
             method = getattr(set_, set_method)
-            return method(*others)
+            return cast(Set[Any], method(*others))
 
     # Where does this method come from?
     def issubset(self, other: Iterable[Any]) -> bool:
@@ -222,7 +222,7 @@ def __sub_or_super(self,
             if not isinstance(other, collections.abc.Set):
                 other = frozenset(other)
             method = getattr(self, set_method)
-            return method(other)
+            return cast(bool, method(other))
 
     # Where does this method come from?
     def symmetric_difference(self, other: Iterable[Any]) -> NoReturn:
@@ -283,7 +283,7 @@ def __update(self,
     def symmetric_difference_update(self, other: Iterable[JSONTypes]) -> NoReturn:
         raise NotImplementedError
 
-    def to_set(self):
+    def to_set(self) -> Set[JSONTypes]:
         'Convert a RedisSet into a plain Python set.'
         return set(self)