Add assigned_stmts() to PEP 695 nodes (#2320)

ChangeLog

@@ -13,6 +13,9 @@ What's New in astroid 3.0.1?
 ============================
 Release date: TBA
 
+* Fix crashes linting code using PEP 695 (Python 3.12) generic type syntax.
+
+  Closes pylint-dev/pylint#9098
 
 
 What's New in astroid 3.0.0?

astroid/nodes/node_classes.py

@@ -3405,6 +3405,11 @@ def _infer(
     ) -> Iterator[ParamSpec]:
         yield self
 
+    assigned_stmts = protocols.generic_type_assigned_stmts
+    """Returns the assigned statement (non inferred) according to the assignment type.
+    See astroid/protocols.py for actual implementation.
+    """
+
 
 class Pass(_base_nodes.NoChildrenNode, _base_nodes.Statement):
     """Class representing an :class:`ast.Pass` node.
@@ -4153,6 +4158,11 @@ def _infer(
     ) -> Iterator[TypeVar]:
         yield self
 
+    assigned_stmts = protocols.generic_type_assigned_stmts
+    """Returns the assigned statement (non inferred) according to the assignment type.
+    See astroid/protocols.py for actual implementation.
+    """
+
 
 class TypeVarTuple(_base_nodes.AssignTypeNode):
     """Class representing a :class:`ast.TypeVarTuple` node.
@@ -4192,6 +4202,11 @@ def _infer(
     ) -> Iterator[TypeVarTuple]:
         yield self
 
+    assigned_stmts = protocols.generic_type_assigned_stmts
+    """Returns the assigned statement (non inferred) according to the assignment type.
+    See astroid/protocols.py for actual implementation.
+    """
+
 
 UNARY_OP_METHOD = {
     "+": "__pos__",

astroid/protocols.py

@@ -915,3 +915,17 @@ def match_as_assigned_stmts(
         and self.pattern is None
     ):
         yield self.parent.parent.subject
+
+
+@decorators.yes_if_nothing_inferred
+def generic_type_assigned_stmts(
+    self: nodes.TypeVar | nodes.TypeVarTuple | nodes.ParamSpec,
+    node: nodes.AssignName,
+    context: InferenceContext | None = None,
+    assign_path: None = None,
+) -> Generator[nodes.NodeNG, None, None]:
+    """Return empty generator (return -> raises StopIteration) so inferred value
+    is Uninferable.
+    """
+    return
+    yield

tests/test_protocols.py

@@ -13,7 +13,7 @@
 
 import astroid
 from astroid import extract_node, nodes
-from astroid.const import PY310_PLUS
+from astroid.const import PY310_PLUS, PY312_PLUS
 from astroid.exceptions import InferenceError
 from astroid.manager import AstroidManager
 from astroid.util import Uninferable, UninferableBase
@@ -415,3 +415,30 @@ def test_assigned_stmts_match_as():
         assert match_as.name
         assigned_match_as = next(match_as.name.assigned_stmts())
         assert assigned_match_as == subject
+
+
+@pytest.mark.skipif(not PY312_PLUS, reason="Generic typing syntax requires python 3.12")
+class TestGenericTypeSyntax:
+    @staticmethod
+    def test_assigned_stmts_type_var():
+        """The result is 'Uninferable' and no exception is raised."""
+        assign_stmts = extract_node("type Point[T] = tuple[float, float]")
+        type_var: nodes.TypeVar = assign_stmts.type_params[0]
+        assigned = next(type_var.name.assigned_stmts())
+        assert assigned is Uninferable
+
+    @staticmethod
+    def test_assigned_stmts_type_var_tuple():
+        """The result is 'Uninferable' and no exception is raised."""
+        assign_stmts = extract_node("type Alias[*Ts] = tuple[*Ts]")
+        type_var_tuple: nodes.TypeVarTuple = assign_stmts.type_params[0]
+        assigned = next(type_var_tuple.name.assigned_stmts())
+        assert assigned is Uninferable
+
+    @staticmethod
+    def test_assigned_stmts_param_spec():
+        """The result is 'Uninferable' and no exception is raised."""
+        assign_stmts = extract_node("type Alias[**P] = Callable[P, int]")
+        param_spec: nodes.ParamSpec = assign_stmts.type_params[0]
+        assigned = next(param_spec.name.assigned_stmts())
+        assert assigned is Uninferable