gistfile1.py

class DeprecationDisplayTest(unittest.TestCase):
    # tests for 19546
    def setUp(self):
        self.new_stderr = StringIO()
        self.new_out = StringIO()
        self.old_stdout = sys.stdout
        self.old_stderr = sys.stderr
        sys.stdout = self.new_out
        sys.stderr = self.new_stderr

    def tearDown(self):
        sys.stderr = self.old_stderr
        sys.stdout = self.old_stdout
        print self.results

    def test_warning_output(self):
        # sys.stderr.write("blah blah")
        warnings.warn("Foo deprecated", DeprecationWarning)
        result = force_text(self.new_stderr.getvalue())
        resultb = force_text(self.new_stderr.getvalue())
        self.results = result + resultb
        # fails
        self.assertTrue("Foo deprecated" in result)