From 98a2e274b44caf7bf4afaf779a37b50a2209c137 Mon Sep 17 00:00:00 2001
From: sobolevn <mail@sobolevn.me>
Date: Wed, 10 Sep 2025 16:06:16 +0300
Subject: [PATCH] gh-138729: Cover `inspect.formatannotationrelativeto` with
 tests (GH-138730) (cherry picked from commit
 f5fa336579d124e389b1c36a5431e7908aaf5e53)

Co-authored-by: sobolevn <mail@sobolevn.me>
---
 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 0a8926e00cf8b9..dff3533591c5f1 100644
--- a/Lib/test/test_inspect/test_inspect.py
+++ b/Lib/test/test_inspect/test_inspect.py
@@ -1749,14 +1749,55 @@ class C(metaclass=M):
 
 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), 'List[str] | int')
         self.assertEqual(inspect.formatannotation(ann1), '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'),
+            'List[testModule.typing.A] | int',
+        )
+
     def test_forwardref(self):
         fwdref = ForwardRef('fwdref')
         self.assertEqual(inspect.formatannotation(fwdref), 'fwdref')
 
+    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),
+            'List[testModule.typing.A] | int',
+        )
+
 
 class TestIsMethodDescriptor(unittest.TestCase):