Added two tests for f(*, **kw) syntax

Lib/test/test_ast.py

@@ -58,6 +58,9 @@ exec_tests = [
     "break",
     # Continue
     "continue",
+    # kw only funcs
+    "def f(*, kw=1): pass",
+    "def f(*, **kw): pass",
 ]
 
 # These are compiled through "single"

Lib/test/test_keywordonlyarg.py

@@ -144,6 +144,13 @@ class KeywordOnlyArgTestCase(unittest.TestCase):
         except TypeError:
             pass
 
+    def test_doublestar_only(self):
+        def f(*, **kw):
+            return kw
+
+        self.assertEqual(f(), {})
+        self.assertEqual(f(k1=1, k2=2), {'k1' : 1, 'k2' : 2})
+
 def test_main():
     run_unittest(KeywordOnlyArgTestCase)