Include a test case for methods with double-underscore names

jpype/_pykeywords.py

@@ -70,7 +70,7 @@ def pysafe(s: str) -> typing.Optional[str]:
     Python that is guaranteed to not collide with the Python grammar.
 
     """
-    if s.startswith("__") and s.endswith('__'):
+    if s.startswith("__") and s.endswith("__") and len(s) >= 4:
         # Dunder methods should not be considered safe.
         # (see system defined names in the Python documentation
         # https://docs.python.org/3/reference/lexical_analysis.html#reserved-classes-of-identifiers

test/harness/jpype/attr/TestKeywords.java

@@ -0,0 +1,30 @@
+/* ****************************************************************************
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+  See NOTICE file for details.
+**************************************************************************** */
+package jpype.attr;
+
+public class TestKeywords
+{
+
+  public String __leading_double_underscore()
+  {
+    return "foo";
+  }
+
+  public String __dunder_name__()
+  {
+    return "foo";
+  }
+}

test/jpypetest/common.py

@@ -127,8 +127,6 @@ def setUp(self):
             jpype.startJVM(jvm_path, *args,
                            convertStrings=self._convertStrings)
         self.jpype = jpype.JPackage('jpype')
-        if sys.version < '3':
-            self.assertCountEqual = self.assertItemsEqual
 
     def tearDown(self):
         pass

test/jpypetest/test_keywords.py

@@ -20,6 +20,7 @@
 import pytest
 
 import jpype
+import common
 
 
 @pytest.mark.parametrize(
@@ -29,6 +30,7 @@
         # Print is no longer a keyword in Python 3, but still protected to
         # avoid API breaking in JPype v1.
         'print',
+        '____',  # Not allowed.
     ]
 )
 def testPySafe__Keywords(identifier):
@@ -48,7 +50,15 @@ def testPySafe__Keywords(identifier):
         'notSpecial__',
         '_notSpecial_',
         '_not__special_',
+        '__', '___',  # Technically these are fine.
     ])
 def testPySafe__NotKeywords(identifier):
     safe = jpype._pykeywords.pysafe(identifier)
     assert safe == identifier
+
+
+class AttributeTestCase(common.JPypeTestCase):
+    def testPySafe(self):
+        cls = jpype.JPackage("jpype").attr.TestKeywords
+        self.assertTrue(hasattr(cls, "__leading_double_underscore"))
+        self.assertFalse(hasattr(cls, "__dunder_name__"))