Use typing.Self

Made use of pep-673 ``Self`` type for method chained methods such as
:meth:`.CacheRegion.configure` and :meth:`.ProxyBackend.wrap`. Pull request
courtesy Viicos.

Fixes: #240
Closes: #241
Pull-request: #241
Pull-request-sha: 33ea2b3

Change-Id: Ic981aebde7b2082f4cac7889b79c9eaa9774770b

Author: Viicos

docs/build/unreleased/240.rst

@@ -0,0 +1,7 @@
+.. change::
+    :tags: bug, typing
+    :tickets: 240
+
+    Made use of pep-673 ``Self`` type for method chained methods such as
+    :meth:`.CacheRegion.configure` and :meth:`.ProxyBackend.wrap`. Pull request
+    courtesy Viicos.

dogpile/cache/api.py

@@ -9,6 +9,8 @@
 from typing import Sequence
 from typing import Union
 
+from ..util.typing import Self
+
 
 class NoValue:
     """Describe a missing cache value.
@@ -18,7 +20,7 @@ class NoValue:
     """
 
     @property
-    def payload(self):
+    def payload(self) -> Self:
         return self
 
     def __repr__(self):
@@ -190,7 +192,9 @@ def __init__(self, arguments: BackendArguments):  # pragma NO COVERAGE
         raise NotImplementedError()
 
     @classmethod
-    def from_config_dict(cls, config_dict, prefix):
+    def from_config_dict(
+        cls, config_dict: Mapping[str, Any], prefix: str
+    ) -> Self:
         prefix_len = len(prefix)
         return cls(
             dict(

dogpile/cache/proxy.py

@@ -9,7 +9,6 @@
 .. versionadded:: 0.5.0  Added support for the :class:`.ProxyBackend` class.
 
 """
-
 from typing import Mapping
 from typing import Optional
 from typing import Sequence
@@ -20,6 +19,7 @@
 from .api import CacheMutex
 from .api import KeyType
 from .api import SerializedReturnType
+from ..util.typing import Self
 
 
 class ProxyBackend(CacheBackend):
@@ -67,7 +67,7 @@ def get(self, key):
     def __init__(self, *arg, **kw):
         pass
 
-    def wrap(self, backend: CacheBackend) -> "ProxyBackend":
+    def wrap(self, backend: CacheBackend) -> Self:
         """Take a backend as an argument and setup the self.proxied property.
         Return an object that be used as a backend by a :class:`.CacheRegion`
         object.

dogpile/cache/region.py

@@ -46,6 +46,7 @@
 from ..util import memoized_property
 from ..util import NameRegistry
 from ..util import PluginLoader
+from ..util.typing import Self
 
 value_version = 2
 """An integer placed in the :class:`.CachedValue`
@@ -426,7 +427,7 @@ def configure(
         wrap: Sequence[Union[ProxyBackend, Type[ProxyBackend]]] = (),
         replace_existing_backend: bool = False,
         region_invalidator: Optional[RegionInvalidationStrategy] = None,
-    ) -> "CacheRegion":
+    ) -> Self:
         """Configure a :class:`.CacheRegion`.
 
         The :class:`.CacheRegion` itself

dogpile/util/typing.py

@@ -0,0 +1,6 @@
+import sys
+
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self  # noqa: F401

setup.cfg

@@ -24,6 +24,7 @@ project_urls =
 install_requires =
   decorator>=4.0.0
   stevedore>=3.0.0
+  typing_extensions>=4.0.1;python_version<'3.11'
 zip_safe = False
 packages = find:
 python_requires = >=3.6