Issue 7815. __unittest in module globals trims frames from reported stacktraces in unittest.

Lib/test/test_unittest.py

@@ -2084,6 +2084,16 @@ class Test_TestResult(TestCase):
                 'Tests getDescription() for a method with a longer '
                 'docstring.'))
 
+    def testStackFrameTrimming(self):
+        class Frame(object):
+            class tb_frame(object):
+                f_globals = {}
+        result = unittest.TestResult()
+        self.assertFalse(result._is_relevant_tb_level(Frame))
+
+        Frame.tb_frame.f_globals['__unittest'] = True
+        self.assertTrue(result._is_relevant_tb_level(Frame))
+
 classDict = dict(unittest.TestResult.__dict__)
 for m in ('addSkip', 'addExpectedFailure', 'addUnexpectedSuccess',
            '__init__'):

Lib/unittest/__init__.py

@@ -64,3 +64,5 @@ from .runner import TextTestRunner, TextTestResult
 
 # deprecated
 _TextTestResult = TextTestResult
+
+__unittest = True

Lib/unittest/__main__.py

@@ -4,5 +4,8 @@ import sys
 if sys.argv[0].endswith("__main__.py"):
     sys.argv[0] = "unittest"
 
+__unittest = True
+
+
 from .main import main
 main(module=None)

Lib/unittest/case.py

@@ -12,6 +12,9 @@ from .util import (
     strclass, safe_repr, sorted_list_difference, unorderable_list_difference
 )
 
+__unittest = True
+
+
 class SkipTest(Exception):
     """
     Raise this exception in a test to skip it.

Lib/unittest/loader.py

@@ -10,6 +10,8 @@ from fnmatch import fnmatch
 
 from . import case, suite
 
+__unittest = True
+
 
 def _CmpToKey(mycmp):
     'Convert a cmp= function into a key= function'

Lib/unittest/main.py

@@ -6,6 +6,8 @@ import types
 
 from . import loader, runner
 
+__unittest = True
+
 
 USAGE_AS_MAIN = """\
 Usage: %(progName)s [options] [tests]

Lib/unittest/result.py

@@ -4,6 +4,8 @@ import traceback
 
 from . import util
 
+__unittest = True
+
 
 class TestResult(object):
     """Holder for test result information.
@@ -98,11 +100,7 @@ class TestResult(object):
         return ''.join(traceback.format_exception(exctype, value, tb))
 
     def _is_relevant_tb_level(self, tb):
-        globs = tb.tb_frame.f_globals
+        return '__unittest' in tb.tb_frame.f_globals
-        is_relevant =  '__name__' in globs and \
-            globs["__name__"].startswith("unittest")
-        del globs
-        return is_relevant
 
     def _count_relevant_tb_levels(self, tb):
         length = 0

Lib/unittest/runner.py

@@ -5,6 +5,8 @@ import time
 
 from . import result
 
+__unittest = True
+
 
 class _WritelnDecorator(object):
     """Used to decorate file-like objects with a handy 'writeln' method"""

Lib/unittest/suite.py

@@ -5,6 +5,8 @@ import sys
 from . import case
 from . import util
 
+__unittest = True
+
 
 class BaseTestSuite(object):
     """A simple test suite that doesn't provide class or module shared fixtures.

Lib/unittest/util.py

@@ -1,5 +1,8 @@
 """Various utility functions."""
 
+__unittest = True
+
+
 def safe_repr(obj):
     try:
         return repr(obj)