From 2422e81e9940e891220b70eed4d92d49815388aa Mon Sep 17 00:00:00 2001
From: sobolevn <mail@sobolevn.me>
Date: Wed, 10 Sep 2025 17:42:49 +0300
Subject: [PATCH] [3.13] gh-138729: Cover `inspect.formatannotationrelativeto`
 with tests (GH-138730) (#138748)

(cherry picked from commit f5fa336579d124e389b1c36a5431e7908aaf5e53)
---
 Lib/test/test_inspect/test_inspect.py | 43 ++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_inspect/test_inspect.py b/Lib/test/test_inspect/test_inspect.py
index f7f73b25b8cb..3e73dc5fe269 100644
--- a/Lib/test/test_inspect/test_inspect.py
+++ b/Lib/test/test_inspect/test_inspect.py
@@ -1986,10 +1986,51 @@ class TestClassesAndFunctions(unittest.TestCase):
 
 class TestFormatAnnotation(unittest.TestCase):
     def test_typing_replacement(self):
-        from test.typinganndata.ann_module9 import ann, ann1
+        from test.typinganndata.ann_module9 import A, ann, ann1
         self.assertEqual(inspect.formatannotation(ann), 'Union[List[str], int]')
         self.assertEqual(inspect.formatannotation(ann1), 'Union[List[testModule.typing.A], int]')
 
+        self.assertEqual(inspect.formatannotation(A, 'testModule.typing'), 'A')
+        self.assertEqual(inspect.formatannotation(A, 'other'), 'testModule.typing.A')
+        self.assertEqual(
+            inspect.formatannotation(ann1, 'testModule.typing'),
+            'Union[List[testModule.typing.A], int]',
+        )
+
+    def test_formatannotationrelativeto(self):
+        from test.typinganndata.ann_module9 import A, ann1
+
+        # Builtin types:
+        self.assertEqual(
+            inspect.formatannotationrelativeto(object)(type),
+            'type',
+        )
+
+        # Custom types:
+        self.assertEqual(
+            inspect.formatannotationrelativeto(None)(A),
+            'testModule.typing.A',
+        )
+
+        class B: ...
+        B.__module__ = 'testModule.typing'
+
+        self.assertEqual(
+            inspect.formatannotationrelativeto(B)(A),
+            'A',
+        )
+
+        self.assertEqual(
+            inspect.formatannotationrelativeto(object)(A),
+            'testModule.typing.A',
+        )
+
+        # Not an instance of "type":
+        self.assertEqual(
+            inspect.formatannotationrelativeto(A)(ann1),
+            'Union[List[testModule.typing.A], int]',
+        )
+
 
 class TestIsMethodDescriptor(unittest.TestCase):
 
-- 
2.47.3