def test_parse_date_arg_raises_error_on_invalid_format(self):
with self.assertRaises(ValueError):
# Missing days part.
cli.parse_date_arg('2016-01')
with self.assertRaises(ValueError):
# Invalid month (31).
cli.parse_date_arg('2016-31-05')
with self.assertRaises(ValueError):
# Empty string.
cli.parse_date_arg('')
def test_parse_date_arg_succeeds_when_date_has_valid_format(self):
self.assertEqual(
datetime.datetime(2016, 1, 11), cli.parse_date_arg('2016-01-11'))
