Method _formatMessage

Lib/unittest/case.py:769–788

Honour the longMessage attribute when generating failure messages. If longMessage is False this means: * Use only an explicit message if it is provided * Otherwise use the standard message for the assert If longMessage is True: * Use the standard message

(self, msg, standardMsg)

            raise self.failureException(msg)

    def _formatMessage(self, msg, standardMsg):
        """Honour the longMessage attribute when generating failure messages.
        If longMessage is False this means:
        * Use only an explicit message if it is provided
        * Otherwise use the standard message for the assert

        If longMessage is True:
        * Use the standard message
        * If an explicit message is provided, plus ' : ' and the explicit message
        """
        if not self.longMessage:
            return msg or standardMsg
        if msg is None:
            return standardMsg
        try:
            # don't switch to '{}' formatting in Python 2.X
            # it changes the way unicode input is handled
            return '%s : %s' % (standardMsg, msg)
        except UnicodeDecodeError:
            return  '%s : %s' % (safe_repr(standardMsg), safe_repr(msg))

    def assertRaises(self, expected_exception, *args, **kwargs):
        """Fail unless an exception of class expected_exception is raised