fix typing

Signed-off-by: Frost Ming <[email protected]>

src/resolvelib/providers.py

@@ -12,7 +12,11 @@
 from .structs import CT, KT, RT, Matches, RequirementInformation
 
 if TYPE_CHECKING:
-    from _typeshed import SupportsRichComparison
+    from typing import Any, Protocol
+
+    class Preference(Protocol):
+        def __lt__(self, __other: Any) -> bool:
+            ...
 
 
 class AbstractProvider(Generic[RT, CT, KT]):
@@ -34,7 +38,7 @@ def get_preference(
         candidates: Mapping[KT, Iterator[CT]],
         information: Mapping[KT, Iterator[RequirementInformation[RT, CT]]],
         backtrack_causes: Sequence[RequirementInformation[RT, CT]],
-    ) -> SupportsRichComparison:
+    ) -> Preference:
         """Produce a sort key for given requirement based on preference.
 
         The preference is defined as "I think this requirement should be

src/resolvelib/resolvers.py

@@ -29,7 +29,7 @@
 )
 
 if TYPE_CHECKING:
-    from _typeshed import SupportsRichComparison
+    from .providers import Preference
 
     class Result(NamedTuple, Generic[RT, CT, KT]):
         mapping: Mapping[KT, CT]
@@ -197,7 +197,7 @@ def _remove_information_from_criteria(
                 criterion.incompatibilities,
             )
 
-    def _get_preference(self, name: KT) -> SupportsRichComparison:
+    def _get_preference(self, name: KT) -> Preference:
         return self._p.get_preference(
             identifier=name,
             resolutions=self.state.mapping,

tests/test_resolvers.py

@@ -203,7 +203,7 @@ def test_pin_conflict_with_self(monkeypatch, reporter):
         ],
     }
 
-    class Provider(AbstractProvider[str, str, Candidate]):
+    class Provider(AbstractProvider[str, Candidate, str]):
         def identify(self, requirement_or_candidate: str | Candidate) -> str:
             result = (
                 Requirement(requirement_or_candidate).name
@@ -260,7 +260,7 @@ def get_updated_criteria_patch(self, candidate):
         Resolution, "_get_updated_criteria", get_updated_criteria_patch
     )
 
-    resolver: Resolver[str, str, Candidate] = Resolver(Provider(), reporter)
+    resolver: Resolver[str, Candidate, str] = Resolver(Provider(), reporter)
     result = resolver.resolve(["child", "parent"])
 
     def get_child_versions(