Fix extraction of nested named expressions

CHANGELOG.md

@@ -1,8 +1,9 @@
 # **Upcoming release**
 
+- #871 Reject extraction of expressions with nested named expressions (@yangfan-yf-yf)
 - #850 Update and pin black version in pre-commit and Github Actions
 - #851 Bump supported python version to up to Python 3.14
-- #852 Implement patchedast handlers for TypeAlias 
+- #852 Implement patchedast handlers for TypeAlias
 - #853 Implement patchedast handlers TypeVar
 - #847 Avoid printing autoimport syntax errors (@yangfan-yf-yf)
 - #623, #819, #863 Support MatchOr, MatchSequence, MatchStar (@jheld, @lieryan)

rope/refactor/usefunction.py

@@ -192,6 +192,7 @@ def _Return(self, node):
 
     def _NamedExpr(self, node):
         self.named_expression += 1
+        self.visit(node.value)
 
     def _Yield(self, node):
         self.yields += 1

ropetest/refactor/extracttest.py

@@ -2373,18 +2373,11 @@ def foo(a):
         start, end = code.index(extract_target), code.index(extract_target) + len(
             extract_target
         )
-        refactored = self.do_extract_method(code, start, end, "new_func")
-        expected = dedent("""\
-            def foo(a):
-                if i, c := new_func(a):
-                    i += 1
-                    c += 1
-                print(i)
-
-            def new_func(a):
-                return (i := a == (c := 5))
-        """)
-        self.assertEqual(expected, refactored)
+        with self.assertRaisesRegex(
+            rope.base.exceptions.RefactoringError,
+            "Extracted piece cannot contain named expression \\(:= operator\\).",
+        ):
+            self.do_extract_method(code, start, end, "new_func")
 
     @testutils.only_for_versions_higher("3.8")
     def test_extract_function_expression_with_inline_assignment_in_inner_expression(