A way to test sys.exit with mocks

gistfile1.py

import sys
import unittest
import mock

@mock.patch('sys.exit')
class Test(unittest.TestCase):

    def test_ok(self, exit):
        sys.exit(-1)
        sys.exit.assert_called_with(-1)

    def test_fail(self, exit):
        sys.exit(-2)
        sys.exit.assert_called_with(-1)