Issue #20530: Argument Clinic's signature format has been revised again.

The new syntax is highly human readable while still preventing false
positives.  The syntax also extends Python syntax to denote "self" and
positional-only parameters, allowing inspect.Signature objects to be
totally accurate for all supported builtins in Python 3.4.

2 files changed, 78 insertions, 12 deletions

diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 10e8c4e..ba7c38d 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -126,20 +126,29 @@ class CAPITest(unittest.TestCase):
         self.assertEqual(_testcapi.docstring_no_signature.__text_signature__, None)
 
         self.assertEqual(_testcapi.docstring_with_invalid_signature.__doc__,
-            "sig= (module, boo)\n"
+            "docstring_with_invalid_signature($module, /, boo)\n"
             "\n"
             "This docstring has an invalid signature."
             )
         self.assertEqual(_testcapi.docstring_with_invalid_signature.__text_signature__, None)
 
+        self.assertEqual(_testcapi.docstring_with_invalid_signature2.__doc__,
+            "docstring_with_invalid_signature2($module, /, boo)\n"
+            "\n"
+            "--\n"
+            "\n"
+            "This docstring also has an invalid signature."
+            )
+        self.assertEqual(_testcapi.docstring_with_invalid_signature2.__text_signature__, None)
+
         self.assertEqual(_testcapi.docstring_with_signature.__doc__,
             "This docstring has a valid signature.")
-        self.assertEqual(_testcapi.docstring_with_signature.__text_signature__, "(module, sig)")
+        self.assertEqual(_testcapi.docstring_with_signature.__text_signature__, "($module, /, sig)")
 
         self.assertEqual(_testcapi.docstring_with_signature_and_extra_newlines.__doc__,
-            "This docstring has a valid signature and some extra newlines.")
+            "\nThis docstring has a valid signature and some extra newlines.")
         self.assertEqual(_testcapi.docstring_with_signature_and_extra_newlines.__text_signature__,
-            "(module, parameter)")
+            "($module, /, parameter)")
 
 
 @unittest.skipUnless(threading, 'Threading required for this test.')
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 862ef82..3f20419 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -1684,7 +1684,6 @@ class TestSignatureObject(unittest.TestCase):
         self.assertEqual(p('sys'), sys.maxsize)
         self.assertEqual(p('exp'), sys.maxsize - 1)
 
-        test_callable(type)
         test_callable(object)
 
         # normal method
@@ -1710,9 +1709,12 @@ class TestSignatureObject(unittest.TestCase):
         # support for 'method-wrapper'
         test_callable(min.__call__)
 
-        class ThisWorksNow:
-            __call__ = type
-        test_callable(ThisWorksNow())
+        # This doesn't work now.
+        # (We don't have a valid signature for "type" in 3.4)
+        with self.assertRaisesRegex(ValueError, "no signature found"):
+            class ThisWorksNow:
+                __call__ = type
+            test_callable(ThisWorksNow())
 
     @cpython_only
     @unittest.skipIf(MISSING_C_DOCSTRINGS,
@@ -2213,11 +2215,11 @@ class TestSignatureObject(unittest.TestCase):
 
         # Test meta-classes without user-defined __init__ or __new__
         class C(type): pass
-        self.assertEqual(str(inspect.signature(C)),
-                         '(object_or_name, bases, dict)')
         class D(C): pass
-        self.assertEqual(str(inspect.signature(D)),
-                         '(object_or_name, bases, dict)')
+        with self.assertRaisesRegex(ValueError, "callable.*is not supported"):
+            self.assertEqual(inspect.signature(C), None)
+        with self.assertRaisesRegex(ValueError, "callable.*is not supported"):
+            self.assertEqual(inspect.signature(D), None)
 
     @unittest.skipIf(MISSING_C_DOCSTRINGS,
                      "Signature information for builtins requires docstrings")
@@ -2768,6 +2770,61 @@ class TestSignaturePrivateHelpers(unittest.TestCase):
         self.assertEqual(getter('($self, obj)'), 'self')
         self.assertEqual(getter('($cls, /, obj)'), 'cls')
 
+    def _strip_non_python_syntax(self, input,
+        clean_signature, self_parameter, last_positional_only):
+        computed_clean_signature, \
+            computed_self_parameter, \
+            computed_last_positional_only = \
+            inspect._signature_strip_non_python_syntax(input)
+        self.assertEqual(computed_clean_signature, clean_signature)
+        self.assertEqual(computed_self_parameter, self_parameter)
+        self.assertEqual(computed_last_positional_only, last_positional_only)
+
+    def test_signature_strip_non_python_syntax(self):
+        self._strip_non_python_syntax(
+            "($module, /, path, mode, *, dir_fd=None, " +
+                "effective_ids=False,\n       follow_symlinks=True)",
+            "(module, path, mode, *, dir_fd=None, " +
+                "effective_ids=False, follow_symlinks=True)",
+            0,
+            0)
+
+        self._strip_non_python_syntax(
+            "($module, word, salt, /)",
+            "(module, word, salt)",
+            0,
+            2)
+
+        self._strip_non_python_syntax(
+            "(x, y=None, z=None, /)",
+            "(x, y=None, z=None)",
+            None,
+            2)
+
+        self._strip_non_python_syntax(
+            "(x, y=None, z=None)",
+            "(x, y=None, z=None)",
+            None,
+            None)
+
+        self._strip_non_python_syntax(
+            "(x,\n    y=None,\n      z = None  )",
+            "(x, y=None, z=None)",
+            None,
+            None)
+
+        self._strip_non_python_syntax(
+            "",
+            "",
+            None,
+            None)
+
+        self._strip_non_python_syntax(
+            None,
+            None,
+            None,
+            None)
+
 
 class TestUnwrap(unittest.TestCase):