[3.13] gh-120722: Set position on RETURN_VALUE in lambda (GH-120724) (#120738)

(cherry picked from commit d8f27cb1141fd3575de816438ed80a916c0560ed)

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

1 files changed, 28 insertions, 1 deletions

diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
index 6be6155..e29c95e 100644
--- a/Lib/test/test_compile.py
+++ b/Lib/test/test_compile.py
@@ -15,7 +15,7 @@ import warnings
 import _testinternalcapi
 
 from test import support
-from test.support import (script_helper, requires_debug_ranges,
+from test.support import (script_helper, requires_debug_ranges, run_code,
                           requires_specialization, get_c_recursion_limit)
 from test.support.bytecode_helper import instructions_with_positions
 from test.support.os_helper import FakePath
@@ -2028,6 +2028,33 @@ class TestSourcePositions(unittest.TestCase):
             code, "LOAD_GLOBAL", line=3, end_line=3, column=4, end_column=9
         )
 
+    def test_lambda_return_position(self):
+        snippets = [
+            "f = lambda: x",
+            "f = lambda: 42",
+            "f = lambda: 1 + 2",
+            "f = lambda: a + b",
+        ]
+        for snippet in snippets:
+            with self.subTest(snippet=snippet):
+                lamb = run_code(snippet)["f"]
+                positions = lamb.__code__.co_positions()
+                # assert that all positions are within the lambda
+                for i, pos in enumerate(positions):
+                    with self.subTest(i=i, pos=pos):
+                        start_line, end_line, start_col, end_col = pos
+                        if i == 0 and start_col == end_col == 0:
+                            # ignore the RESUME in the beginning
+                            continue
+                        self.assertEqual(start_line, 1)
+                        self.assertEqual(end_line, 1)
+                        code_start = snippet.find(":") + 2
+                        code_end = len(snippet)
+                        self.assertGreaterEqual(start_col, code_start)
+                        self.assertLessEqual(end_col, code_end)
+                        self.assertGreaterEqual(end_col, start_col)
+                        self.assertLessEqual(end_col, code_end)
+
 
 class TestExpectedAttributes(unittest.TestCase):