test_with_inputs.py

import functools
import unittest
import mock

__inputoutput__ = "__inputoutput__"

def with_inputs(input, output, identifier=None):
    def decorator(f):
        try:
            io = getattr(f, __inputoutput__)
        except AttributeError:
            io = []
            setattr(f, __inputoutput__, io)
        io.append((input, output, identifier))
        return f
    return decorator

class TestWithData(unittest.TestCase):
    class __metaclass__(type):
        def __new__(meta, name, bases, clsdict):
            to_remove = []
            for methodname, method in clsdict.items():
                if not hasattr(method, __inputoutput__):
                    continue
                to_remove.append(methodname)
                io = getattr(method, __inputoutput__)
                delattr(method, __inputoutput__)
                for input, output, identifier in io:
                    @functools.wraps(method)
                    def dummy(self, method=method, input=input, output=output):
                        method(self, input, output)
                    if identifier:
                        test_name = '_'.join((methodname, identifier))
                    else:
                        test_name = '%s(%s, %s)' % (methodname, input, output)
                    dummy.__name__ = test_name
                    if test_name in clsdict:
                        raise ValueError('Already defined %s' % test_name)
                    clsdict[test_name] = dummy

            for methodname in to_remove:
                del clsdict[methodname]

            return type.__new__(meta, name, bases, clsdict)

class TestAdd(TestWithData):
    @with_inputs((2, 3), 5)
    @with_inputs((1, 1), 2)
    @with_inputs((1, 1), 3, 'foo')
    @with_inputs((1, 1), 3, 'bar')
    def test_add(self, input, output):
        a, b = input
        self.assertEqual(a + b, output)

    @with_inputs(1, 1)
    @with_inputs(1, 2)
    @mock.patch('sys.path')
    def test_reflexive(self, input, output, mock_sys):
        print mock_sys
        self.assertEqual(input, output)