Add typing and small refactors to namedtuple brain (#1681)

Author: DanielNoord

astroid/brain/brain_namedtuple_enum.py

@@ -12,8 +12,8 @@
 from textwrap import dedent
 
 import astroid
-from astroid import arguments, inference_tip, nodes, util
-from astroid.builder import AstroidBuilder, extract_node
+from astroid import arguments, bases, inference_tip, nodes, util
+from astroid.builder import AstroidBuilder, _extract_single_node, extract_node
 from astroid.context import InferenceContext
 from astroid.exceptions import (
     AstroidTypeError,
@@ -72,7 +72,7 @@ def _extract_namedtuple_arg_or_keyword(  # pylint: disable=inconsistent-return-s
 
 def infer_func_form(
     node: nodes.Call,
-    base_type: nodes.NodeNG,
+    base_type: list[nodes.NodeNG],
     context: InferenceContext | None = None,
     enum: bool = False,
 ) -> tuple[nodes.ClassDef, str, list[str]]:
@@ -146,7 +146,7 @@ def infer_func_form(
     class_node.parent = node.parent
     class_node.postinit(
         # set base class=tuple
-        bases=[base_type],
+        bases=base_type,
         body=[],
         decorators=None,
     )
@@ -186,7 +186,7 @@ def infer_named_tuple(
     node: nodes.Call, context: InferenceContext | None = None
 ) -> Iterator[nodes.ClassDef]:
     """Specific inference function for namedtuple Call node"""
-    tuple_base_name = nodes.Name(name="tuple", parent=node.root())
+    tuple_base_name: list[nodes.NodeNG] = [nodes.Name(name="tuple", parent=node.root())]
     class_node, name, attributes = infer_func_form(
         node, tuple_base_name, context=context
     )
@@ -295,9 +295,11 @@ def _check_namedtuple_attributes(typename, attributes, rename=False):
     return attributes
 
 
-def infer_enum(node, context=None):
+def infer_enum(
+    node: nodes.Call, context: InferenceContext | None = None
+) -> Iterator[bases.Instance]:
     """Specific inference function for enum Call node."""
-    enum_meta = extract_node(
+    enum_meta = _extract_single_node(
         """
     class EnumMeta(object):
         'docstring'
@@ -331,7 +333,7 @@ def value(self):
         __members__ = ['']
     """
     )
-    class_node = infer_func_form(node, enum_meta, context=context, enum=True)[0]
+    class_node = infer_func_form(node, [enum_meta], context=context, enum=True)[0]
     return iter([class_node.instantiate_class()])
 
 

astroid/nodes/scoped_nodes/scoped_nodes.py

@@ -2508,12 +2508,10 @@ def instance_attr(self, name, context=None):
             return values
         raise AttributeInferenceError(target=self, attribute=name, context=context)
 
-    def instantiate_class(self):
+    def instantiate_class(self) -> bases.Instance:
         """Get an :class:`Instance` of the :class:`ClassDef` node.
 
-        :returns: An :class:`Instance` of the :class:`ClassDef` node,
-            or self if this is not possible.
-        :rtype: Instance or ClassDef
+        :returns: An :class:`Instance` of the :class:`ClassDef` node
         """
         try:
             if any(cls.name in EXCEPTION_BASE_CLASSES for cls in self.mro()):