Add typing to ``_function_type`` and ``_build_proxy_class``

1 files changed, 5 insertions, 3 deletions

diff --git a/astroid/helpers.py b/astroid/helpers.py
index 6924e4af..928aeed6 100644
--- a/astroid/helpers.py
+++ b/astroid/helpers.py
@@ -21,13 +21,15 @@ from astroid.nodes import scoped_nodes
 from astroid.typing import InferenceResult
 
 
-def _build_proxy_class(cls_name, builtins):
+def _build_proxy_class(cls_name: str, builtins: nodes.Module) -> nodes.ClassDef:
     proxy = raw_building.build_class(cls_name)
     proxy.parent = builtins
     return proxy
 
 
-def _function_type(function, builtins):
+def _function_type(
+    function: nodes.Lambda | bases.UnboundMethod, builtins: nodes.Module
+) -> nodes.ClassDef:
     if isinstance(function, scoped_nodes.Lambda):
         if function.root().name == "builtins":
             cls_name = "builtin_function_or_method"
@@ -35,7 +37,7 @@ def _function_type(function, builtins):
             cls_name = "function"
     elif isinstance(function, bases.BoundMethod):
         cls_name = "method"
-    elif isinstance(function, bases.UnboundMethod):
+    else:
         cls_name = "function"
     return _build_proxy_class(cls_name, builtins)