Issue #19674: inspect.signature() now produces a correct signature

for some builtins.

2 files changed, 32 insertions, 4 deletions

diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 000079e..6f75b77 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -109,6 +109,35 @@ class CAPITest(unittest.TestCase):
         self.assertRaises(TypeError, _posixsubprocess.fork_exec,
                           Z(),[b'1'],3,[1, 2],5,6,7,8,9,10,11,12,13,14,15,16,17)
 
+    def test_docstring_signature_parsing(self):
+
+        self.assertEqual(_testcapi.no_docstring.__doc__, None)
+        self.assertEqual(_testcapi.no_docstring.__text_signature__, None)
+
+        self.assertEqual(_testcapi.docstring_empty.__doc__, "")
+        self.assertEqual(_testcapi.docstring_empty.__text_signature__, None)
+
+        self.assertEqual(_testcapi.docstring_no_signature.__doc__,
+            "This docstring has no signature.")
+        self.assertEqual(_testcapi.docstring_no_signature.__text_signature__, None)
+
+        self.assertEqual(_testcapi.docstring_with_invalid_signature.__doc__,
+            "docstring_with_invalid_signature (boo)\n"
+            "\n"
+            "This docstring has an invalid signature."
+            )
+        self.assertEqual(_testcapi.docstring_with_invalid_signature.__text_signature__, None)
+
+        self.assertEqual(_testcapi.docstring_with_signature.__doc__,
+            "This docstring has a valid signature.")
+        self.assertEqual(_testcapi.docstring_with_signature.__text_signature__, "(sig)")
+
+        self.assertEqual(_testcapi.docstring_with_signature_and_extra_newlines.__doc__,
+            "This docstring has a valid signature and some extra newlines.")
+        self.assertEqual(_testcapi.docstring_with_signature_and_extra_newlines.__text_signature__,
+            "(parameter)")
+
+
 @unittest.skipUnless(threading, 'Threading required for this test.')
 class TestPendingCalls(unittest.TestCase):
 
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 9d34904..0258d3df 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -1588,10 +1588,9 @@ class TestSignatureObject(unittest.TestCase):
         with self.assertRaisesRegex(ValueError, 'not supported by signature'):
             # support for 'method-wrapper'
             inspect.signature(min.__call__)
-        with self.assertRaisesRegex(ValueError,
-                                     'no signature found for builtin function'):
-            # support for 'method-wrapper'
-            inspect.signature(min)
+        self.assertEqual(inspect.signature(min), None)
+        signature = inspect.signature(os.stat)
+        self.assertTrue(isinstance(signature, inspect.Signature))
 
     def test_signature_on_non_function(self):
         with self.assertRaisesRegex(TypeError, 'is not a callable object'):