fix issue101: wrong args to unittest.TestCase test function now

produce better output

CHANGELOG

@@ -3,6 +3,9 @@ Changes between 2.2.1 and 2.2.2.dev
 
 - make monkeypatch more robust against intermediate dict/env deletions
 - use distribute_setup script defaulting to 0.6.24 if no setuptools is installed
+- fix issue101: wrong args to unittest.TestCase test function now
+  produce better output
+  
 
 Changes between 2.2.0 and 2.2.1
 ----------------------------------------

_pytest/__init__.py

@@ -1,2 +1,2 @@
 #
-__version__ = '2.2.2.dev1'
+__version__ = '2.2.2.dev2'

_pytest/unittest.py

@@ -108,7 +108,10 @@ class TestCaseFunction(pytest.Function):
 
     def _prunetraceback(self, excinfo):
         pytest.Function._prunetraceback(self, excinfo)
-        excinfo.traceback = excinfo.traceback.filter(lambda x:not x.frame.f_globals.get('__unittest'))
+        traceback = excinfo.traceback.filter(
+            lambda x:not x.frame.f_globals.get('__unittest'))
+        if traceback:
+            excinfo.traceback = traceback
 
 @pytest.mark.tryfirst
 def pytest_runtest_makereport(item, call):

setup.py

@@ -24,7 +24,7 @@ def main():
         name='pytest',
         description='py.test: simple powerful testing with Python',
         long_description = long_description,
-        version='2.2.2.dev1',
+        version='2.2.2.dev2',
         url='http://pytest.org',
         license='MIT license',
         platforms=['unix', 'linux', 'osx', 'cygwin', 'win32'],

testing/test_unittest.py

@@ -448,3 +448,14 @@ def test_unorderable_types(testdir):
     result = testdir.runpytest()
     assert "TypeError" not in result.stdout.str()
     assert result.ret == 0
+
+def test_unittest_typerror_traceback(testdir):
+    testdir.makepyfile("""
+        import unittest
+        class TestJoinEmpty(unittest.TestCase):
+            def test_hello(self, arg1):
+                pass
+    """)
+    result = testdir.runpytest()
+    assert "TypeError" in result.stdout.str()
+    assert result.ret == 1