Fix some typing in helpers.py

Author: DanielNoord

astroid/brain/brain_builtin_inference.py

@@ -22,6 +22,7 @@
 )
 from astroid.manager import AstroidManager
 from astroid.nodes import scoped_nodes
+from astroid.typing import InferenceResult
 
 OBJECT_DUNDER_NEW = "object.__new__"
 
@@ -707,12 +708,12 @@ def infer_issubclass(callnode, context: InferenceContext | None = None):
     return nodes.Const(issubclass_bool)
 
 
-def infer_isinstance(callnode, context: InferenceContext | None = None):
+def infer_isinstance(
+    callnode: nodes.Call, context: InferenceContext | None = None
+) -> nodes.Const:
     """Infer isinstance calls.
 
     :param nodes.Call callnode: an isinstance call
-    :rtype nodes.Const: Boolean Const value of isinstance call
-
     :raises UseInferenceDefault: If the node cannot be inferred
     """
     call = arguments.CallSite.from_call(callnode, context=context)
@@ -744,7 +745,9 @@ def infer_isinstance(callnode, context: InferenceContext | None = None):
     return nodes.Const(isinstance_bool)
 
 
-def _class_or_tuple_to_container(node, context: InferenceContext | None = None):
+def _class_or_tuple_to_container(
+    node: InferenceResult, context: InferenceContext | None = None
+) -> list[InferenceResult]:
     # Move inferences results into container
     # to simplify later logic
     # raises InferenceError if any of the inferences fall through
@@ -761,9 +764,6 @@ def _class_or_tuple_to_container(node, context: InferenceContext | None = None):
             ]
         except StopIteration as e:
             raise InferenceError(node=node, context=context) from e
-        class_container = [
-            klass_node for klass_node in class_container if klass_node is not None
-        ]
     else:
         class_container = [node_infer]
     return class_container

astroid/helpers.py

@@ -28,7 +28,8 @@ def _build_proxy_class(cls_name: str, builtins: nodes.Module) -> nodes.ClassDef:
 
 
 def _function_type(
-    function: nodes.Lambda | bases.UnboundMethod, builtins: nodes.Module
+    function: nodes.Lambda | nodes.FunctionDef | bases.UnboundMethod,
+    builtins: nodes.Module,
 ) -> nodes.ClassDef:
     if isinstance(function, (scoped_nodes.Lambda, scoped_nodes.FunctionDef)):
         if function.root().name == "builtins":
@@ -96,20 +97,19 @@ def object_type(
 
 
 def _object_type_is_subclass(
-    obj_type, class_or_seq, context: InferenceContext | None = None
-):
-    if not isinstance(class_or_seq, (tuple, list)):
-        class_seq = (class_or_seq,)
-    else:
-        class_seq = class_or_seq
-
-    if isinstance(obj_type, util.UninferableBase):
+    obj_type: InferenceResult | None,
+    class_or_seq: list[InferenceResult],
+    context: InferenceContext | None = None,
+) -> util.UninferableBase | bool:
+    if isinstance(obj_type, util.UninferableBase) or not isinstance(
+        obj_type, nodes.ClassDef
+    ):
         return util.Uninferable
 
     # Instances are not types
     class_seq = [
         item if not isinstance(item, bases.Instance) else util.Uninferable
-        for item in class_seq
+        for item in class_or_seq
     ]
     # strict compatibility with issubclass
     # issubclass(type, (object, 1)) evaluates to true
@@ -124,13 +124,13 @@ def _object_type_is_subclass(
     return False
 
 
-def object_isinstance(node, class_or_seq, context: InferenceContext | None = None):
+def object_isinstance(
+    node: InferenceResult,
+    class_or_seq: list[InferenceResult],
+    context: InferenceContext | None = None,
+) -> util.UninferableBase | bool:
     """Check if a node 'isinstance' any node in class_or_seq.
 
-    :param node: A given node
-    :param class_or_seq: Union[nodes.NodeNG, Sequence[nodes.NodeNG]]
-    :rtype: bool
-
     :raises AstroidTypeError: if the given ``classes_or_seq`` are not types
     """
     obj_type = object_type(node, context)
@@ -139,13 +139,13 @@ def object_isinstance(node, class_or_seq, context: InferenceContext | None = Non
     return _object_type_is_subclass(obj_type, class_or_seq, context=context)
 
 
-def object_issubclass(node, class_or_seq, context: InferenceContext | None = None):
+def object_issubclass(
+    node: nodes.NodeNG,
+    class_or_seq: list[InferenceResult],
+    context: InferenceContext | None = None,
+) -> util.UninferableBase | bool:
     """Check if a type is a subclass of any node in class_or_seq.
 
-    :param node: A given node
-    :param class_or_seq: Union[Nodes.NodeNG, Sequence[nodes.NodeNG]]
-    :rtype: bool
-
     :raises AstroidTypeError: if the given ``classes_or_seq`` are not types
     :raises AstroidError: if the type of the given node cannot be inferred
         or its type's mro doesn't work
@@ -270,7 +270,7 @@ def object_len(node, context: InferenceContext | None = None):
     if (
         isinstance(node_frame, scoped_nodes.FunctionDef)
         and node_frame.name == "__len__"
-        and hasattr(inferred_node, "_proxied")
+        and isinstance(inferred_node, bases.Proxy)
         and inferred_node._proxied == node_frame.parent
     ):
         message = (