test_format.py 文件源码

def test_it_catches_registered_errors(self):
        checker = FormatChecker()
        cause = self.fn.side_effect = ValueError()

        checker.checks("foo", raises=ValueError)(self.fn)

        with self.assertRaises(FormatError) as cm:
            checker.check("bar", "foo")

        self.assertIs(cm.exception.cause, cause)
        self.assertIs(cm.exception.__cause__, cause)

        # Unregistered errors should not be caught
        self.fn.side_effect = AttributeError
        with self.assertRaises(AttributeError):
            checker.check("bar", "foo")