def test_getsourcevalue_raises_keyerrors(self):
f = Filter('fieldname')
with self.assertRaises(KeyError):
f.get_source_value('legume', {'foo': 'bar'})
def test_getsourcevalue_does_what_it_says_on_the_tin(self):
f = Filter('fieldname')
bar = f.get_source_value('foo', {'foo': 'bar'})
assert bar == 'bar'