def test_wrapping(self):
a1 = Mock()
a1.f = Mock(__name__='f', side_effect=IOError)
a2 = Mock()
a2.f = Mock(__name__='f', return_value=2)
a = RetryGoRound([a1, a2], lambda ex: isinstance(ex, IOError))
self.assertEqual(a.f('foo', bar='baz'), 2)
a1.f.assert_called_once_with('foo', bar='baz')
a2.f.assert_called_once_with('foo', bar='baz')
self.assertEqual(a.f.__name__, 'f')
def test_can_wrap_around(self):
a1 = Mock()
a1.f = Mock(__name__='f', side_effect=[IOError, 1])
a2 = Mock()
a2.f = Mock(__name__='f', side_effect=[2, IOError])
a = RetryGoRound([a1, a2], lambda ex: isinstance(ex, IOError))
self.assertEqual(a.f(), 2)
self.assertEqual(a.f(), 1)
self.assertEqual(a1.f.call_count, 2)
self.assertEqual(a2.f.call_count, 2)
def test_success(self):
a1 = Mock()
# need __name__ so wraps() will work
a1.f = Mock(__name__='f', return_value=1)
a2 = Mock()
a2.f = Mock(__name__='f', return_value=2)
a = RetryGoRound([a1, a2], lambda ex: isinstance(ex, IOError))
self.assertEqual(a.f(), 1)
self.assertEqual(a1.f.call_count, 1)
# never needed to try a2.f()
self.assertEqual(a2.f.call_count, 0)
def test_one_failure(self):
a1 = Mock()
a1.f = Mock(__name__='f', side_effect=IOError)
a1.x = 100
a2 = Mock()
a2.f = Mock(__name__='f', return_value=2)
a2.x = 200
a = RetryGoRound([a1, a2], lambda ex: isinstance(ex, IOError))
self.assertEqual(a.x, 100)
self.assertEqual(a.f(), 2)
# a2 was the last alternative that worked, so now we get x from it
self.assertEqual(a.x, 200)
# this time we should skip calling a1.f() entirely
self.assertEqual(a.f(), 2)
self.assertEqual(a1.f.call_count, 1)
self.assertEqual(a2.f.call_count, 2)
def test_unrecoverable_error(self):
a1 = Mock()
a1.f = Mock(__name__='f', side_effect=ValueError)
a2 = Mock()
a2.f = Mock(__name__='f', return_value=2)
a = RetryGoRound([a1, a2], lambda ex: isinstance(ex, IOError))
self.assertRaises(ValueError, a.f)
self.assertRaises(ValueError, a.f)
self.assertEqual(a1.f.call_count, 2)
self.assertEqual(a2.f.call_count, 0)
def test_all_fail(self):
a1 = Mock()
a1.f = Mock(__name__='f', side_effect=IOError)
a1.x = 100
a2 = Mock()
a2.f = Mock(__name__='f', side_effect=IOError)
a2.x = 200
a = RetryGoRound([a1, a2], lambda ex: isinstance(ex, IOError))
self.assertEqual(a.x, 100)
# ran out of alternatives
self.assertRaises(IOError, a.f)
# nothing worked, so we're still pointing at a1
self.assertEqual(a.x, 100)
# yep, still broken
self.assertRaises(IOError, a.f)
self.assertEqual(a1.f.call_count, 2)
self.assertEqual(a2.f.call_count, 2)