SuccessResultOf

matchers.py

from testtools.matchers import Mismatch


class SuccessResultOf(object):
    """
    Match if a Deferred has fired with a result.
    """
    def __init__(self, resultMatcher=None):
        self.resultMatcher = resultMatcher


    def __str__(self):
        return 'SuccessResultOf(%s)' % (self.resultMatcher or '')


    def match(self, matchee):
        result = []
        matchee.addBoth(result.append)
        if not result:
            return Mismatch(
                'Success result expected on %r, found no result instead' % (
                    matchee,))
        elif isinstance(result[0], Failure):
            return Mismatch(
                'Success result expected on %r,'
                ' found failure result instead:\n%s' % (
                    matchee, result[0].getTraceback()))
        elif self.resultMatcher:
            return self.resultMatcher.match(result[0])
        return None