Improve typing of inference functions

astroid/inference.py

@@ -254,7 +254,6 @@ def infer_name(
     return bases._infer_stmts(stmts, context, frame)
 
 
-# pylint: disable=no-value-for-parameter
 # The order of the decorators here is important
 # See https://github.com/pylint-dev/astroid/commit/0a8a75db30da060a24922e05048bc270230f5
 nodes.Name._infer = decorators.raise_if_nothing_inferred(

astroid/inference_tip.py

@@ -6,20 +6,19 @@
 
 from __future__ import annotations
 
-import sys
 from collections.abc import Callable, Iterator
+from typing import TYPE_CHECKING
 
 from astroid.context import InferenceContext
 from astroid.exceptions import InferenceOverwriteError, UseInferenceDefault
 from astroid.nodes import NodeNG
-from astroid.typing import InferenceResult, InferFn
-
-if sys.version_info >= (3, 11):
-    from typing import ParamSpec
-else:
-    from typing_extensions import ParamSpec
-
-_P = ParamSpec("_P")
+from astroid.typing import (
+    _P,
+    InferenceResult,
+    InferFn,
+    InferFnExplicit,
+    InferFnTransform,
+)
 
 _cache: dict[
     tuple[InferFn, NodeNG, InferenceContext | None], list[InferenceResult]
@@ -35,12 +34,18 @@ def clear_inference_tip_cache() -> None:
 
 def _inference_tip_cached(
     func: Callable[_P, Iterator[InferenceResult]],
-) -> Callable[_P, Iterator[InferenceResult]]:
+) -> InferFnExplicit:
     """Cache decorator used for inference tips."""
 
-    def inner(*args: _P.args, **kwargs: _P.kwargs) -> Iterator[InferenceResult]:
+    def inner(
+        *args: _P.args, **kwargs: _P.kwargs
+    ) -> Iterator[InferenceResult] | list[InferenceResult]:
         node = args[0]
         context = args[1]
+        if TYPE_CHECKING:
+            assert isinstance(node, NodeNG)
+            assert context is None or isinstance(context, InferenceContext)
+
         partial_cache_key = (func, node)
         if partial_cache_key in _CURRENTLY_INFERRING:
             # If through recursion we end up trying to infer the same
@@ -64,7 +69,9 @@ def inner(*args: _P.args, **kwargs: _P.kwargs) -> Iterator[InferenceResult]:
     return inner
 
 
-def inference_tip(infer_function: InferFn, raise_on_overwrite: bool = False) -> InferFn:
+def inference_tip(
+    infer_function: InferFn, raise_on_overwrite: bool = False
+) -> InferFnTransform:
     """Given an instance specific inference function, return a function to be
     given to AstroidManager().register_transform to set this inference function.
 
@@ -100,7 +107,6 @@ def transform(node: NodeNG, infer_function: InferFn = infer_function) -> NodeNG:
                     node=node,
                 )
             )
-        # pylint: disable=no-value-for-parameter
         node._explicit_inference = _inference_tip_cached(infer_function)
         return node
 

astroid/nodes/node_ng.py

@@ -35,7 +35,7 @@
 from astroid.nodes.as_string import AsStringVisitor
 from astroid.nodes.const import OP_PRECEDENCE
 from astroid.nodes.utils import Position
-from astroid.typing import InferenceErrorInfo, InferenceResult, InferFn
+from astroid.typing import InferenceErrorInfo, InferenceResult, InferFnExplicit
 
 if TYPE_CHECKING:
     from astroid import nodes
@@ -80,7 +80,7 @@ class NodeNG:
     _other_other_fields: ClassVar[tuple[str, ...]] = ()
     """Attributes that contain AST-dependent fields."""
     # instance specific inference function infer(node, context)
-    _explicit_inference: InferFn | None = None
+    _explicit_inference: InferFnExplicit | None = None
 
     def __init__(
         self,

astroid/typing.py

@@ -4,14 +4,28 @@
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Any, Callable, Generator, TypedDict, TypeVar, Union
+import sys
+from typing import (
+    TYPE_CHECKING,
+    Callable,
+    Generator,
+    Iterator,
+    TypedDict,
+    TypeVar,
+    Union,
+)
 
 if TYPE_CHECKING:
     from astroid import bases, exceptions, nodes, transforms, util
     from astroid.context import InferenceContext
     from astroid.interpreter._import import spec
 
+if sys.version_info >= (3, 11):
+    from typing import ParamSpec
+else:
+    from typing_extensions import ParamSpec
 
+_P = ParamSpec("_P")
 _NodesT = TypeVar("_NodesT", bound="nodes.NodeNG")
 
 
@@ -24,9 +38,6 @@ class InferenceErrorInfo(TypedDict):
     context: InferenceContext | None
 
 
-InferFn = Callable[..., Any]
-
-
 class AstroidManagerBrain(TypedDict):
     """Dictionary to store relevant information for a AstroidManager class."""
 
@@ -67,3 +78,7 @@ class AstroidManagerBrain(TypedDict):
     ],
     Generator[InferenceResult, None, None],
 ]
+
+InferFn = Callable[..., Iterator[InferenceResult]]
+InferFnExplicit = Callable[_P, Union[Iterator[InferenceResult], list[InferenceResult]]]
+InferFnTransform = Callable[[_NodesT, InferFn], _NodesT]