Clarify on non-Module roots

astroid/nodes/node_ng.py

@@ -21,7 +21,7 @@
     overload,
 )
 
-from astroid import util
+from astroid import nodes, util
 from astroid.context import InferenceContext
 from astroid.exceptions import (
     AstroidError,
@@ -43,7 +43,7 @@
 
 
 if TYPE_CHECKING:
     from astroid import nodes
     from astroid.nodes import _base_nodes
 
 
@@ -332,11 +332,13 @@
         :returns: The root node.
         """
         if not (parent := self.parent):
-            return self  # type: ignore[return-value] # Only 'Module' does not have a parent node.
+            assert isinstance(self, nodes.Module)
+            return self
 
         while parent.parent:
             parent = parent.parent
-        return parent  # type: ignore[return-value] # Only 'Module' does not have a parent node.
+        assert isinstance(parent, nodes.Module)
+        return parent
 
     def child_sequence(self, child):
         """Search for the sequence that contains this child.

astroid/nodes/scoped_nodes/scoped_nodes.py

@@ -40,15 +40,15 @@
 from astroid.interpreter.dunder_lookup import lookup
 from astroid.interpreter.objectmodel import ClassModel, FunctionModel, ModuleModel
 from astroid.manager import AstroidManager
 from astroid.nodes import (
     Arguments,
     Const,
     NodeNG,
     Unknown,
     _base_nodes,
     const_factory,
     node_classes,
 )
 from astroid.nodes.scoped_nodes.mixin import ComprehensionScope, LocalsDictNodeNG
 from astroid.nodes.scoped_nodes.utils import builtin_lookup
 from astroid.nodes.utils import Position
@@ -2037,7 +2037,7 @@
             col_offset=0,
             end_lineno=0,
             end_col_offset=0,
-            parent=Unknown(),
+            parent=caller.parent,
         )
 
         # Get the bases of the class.
@@ -2071,7 +2071,6 @@
                 if isinstance(attr, node_classes.Const) and isinstance(attr.value, str):
                     result.locals[attr.value] = [value]
 
-        result.parent = caller.parent
         return result
 
     def infer_call_result(

astroid/raw_building.py

@@ -670,9 +670,8 @@ def _astroid_bootstrapping() -> None:
             col_offset=0,
             end_lineno=0,
             end_col_offset=0,
-            parent=nodes.Unknown(),
+            parent=astroid_builtin,
         )
-        _UnionTypeType.parent = astroid_builtin
         union_type_doc_node = (
             nodes.Const(value=types.UnionType.__doc__)
             if types.UnionType.__doc__
@@ -707,9 +706,8 @@ def _astroid_bootstrapping() -> None:
                 col_offset=0,
                 end_lineno=0,
                 end_col_offset=0,
-                parent=nodes.Unknown(),
+                parent=astroid_builtin,
             )
-            klass.parent = astroid_builtin
             doc = _type.__doc__ if isinstance(_type.__doc__, str) else None
             klass.postinit(
                 bases=[],

tests/test_nodes.py

@@ -37,6 +37,7 @@
     ParentMissingError,
     StatementMissing,
 )
+from astroid.manager import AstroidManager
 from astroid.nodes.node_classes import (
     AssignAttr,
     AssignName,
@@ -1960,7 +1961,9 @@ def test_str_repr_no_warnings(node):
         if name == "self":
             continue
 
-        if "int" in param_type.annotation:
+        if name == "parent" and "NodeNG" in param_type.annotation:
+            args[name] = AstroidManager().adhoc_module
+        elif "int" in param_type.annotation:
             args[name] = random.randint(0, 50)
         elif (
             "NodeNG" in param_type.annotation