bpo-45249: Ensure the traceback module prints correctly syntax errors with ranges (GH-28575)

(cherry picked from commit 20f439b6b9e1032930a31b88694ab9f37a09e6b4)

Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
index ee18383478..fabe5d01a9 100644
--- a/Lib/test/test_traceback.py
+++ b/Lib/test/test_traceback.py
@@ -39,6 +39,9 @@ class TracebackCases(unittest.TestCase):
     def syntax_error_with_caret_2(self):
         compile("1 +\n", "?", "exec")
 
+    def syntax_error_with_caret_range(self):
+        compile("f(x, y for y in range(30), z)", "?", "exec")
+
     def syntax_error_bad_indentation(self):
         compile("def spam():\n  print(1)\n print(2)", "?", "exec")
 
@@ -55,18 +58,28 @@ class TracebackCases(unittest.TestCase):
         self.assertTrue(err[1].strip() == "return x!")
         self.assertIn("^", err[2]) # third line has caret
         self.assertEqual(err[1].find("!"), err[2].find("^")) # in the right place
+        self.assertEqual(err[2].count("^"), 1)
 
         err = self.get_exception_format(self.syntax_error_with_caret_2,
                                         SyntaxError)
         self.assertIn("^", err[2]) # third line has caret
         self.assertEqual(err[2].count('\n'), 1)   # and no additional newline
         self.assertEqual(err[1].find("+") + 1, err[2].find("^"))  # in the right place
+        self.assertEqual(err[2].count("^"), 1)
 
         err = self.get_exception_format(self.syntax_error_with_caret_non_ascii,
                                         SyntaxError)
         self.assertIn("^", err[2]) # third line has caret
         self.assertEqual(err[2].count('\n'), 1)   # and no additional newline
         self.assertEqual(err[1].find("+") + 1, err[2].find("^"))  # in the right place
+        self.assertEqual(err[2].count("^"), 1)
+
+        err = self.get_exception_format(self.syntax_error_with_caret_range,
+                                        SyntaxError)
+        self.assertIn("^", err[2]) # third line has caret
+        self.assertEqual(err[2].count('\n'), 1)   # and no additional newline
+        self.assertEqual(err[1].find("y"), err[2].find("^"))  # in the right place
+        self.assertEqual(err[2].count("^"), len("y for y in range(30)"))
 
     def test_nocaret(self):
         exc = SyntaxError("error", ("x.py", 23, None, "bad syntax"))