An implementation vows.js style macros in Python

client.py

class Response(object):
    def __init__(self, status=200):
        self.status = status

class Client:
    def get(self, path):
        return Response(200)

    def post(self, path):
        return Response(405)

console output

$ python tests.py
.F.
======================================================================
FAIL: GET /resources (no key): should respond with a 403
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/joshbohde/code/minstrel/vows.py", line 26, in inner
    func(self, *args)
  File "tests.py", line 13, in <lambda>
    return lambda self, response: self.assertEquals(response.status, status)
AssertionError: 200 != 403

----------------------------------------------------------------------
Ran 3 tests in 0.000s

FAILED (failures=1)

test.py

import unittest

from vows import Describe
from client import Client

def responds_with(status):
    def topic(self, name):
        req, path = name.split()[:2]
        client = Client()
        return getattr(client, req.lower())(path)

    def assertStatus(status):
        return lambda self, response: self.assertEquals(response.status, status)
    
    return dict([('topic', topic),
                 ('should respond with a %s' % (status), assertStatus(status))])



vows = Describe('Sample Test')
   
TestFour = vows.batch({
    'GET /': responds_with(200), 
    'POST /': responds_with(405), 
    'GET /resources (no key)': responds_with(403)
    })

if __name__ == '__main__':
    unittest.main()

vows.py

import unittest

class Describe:
    def __init__(self, name, *bases):
        if not bases:
            bases = (unittest.TestCase,)
        self.bases = tuple(bases)
        self.name = name

    def batch(self, contexts):
        def vow(name, context):
            topic = context.pop('topic')
            def inner(self):
                try:
                    args = topic(self, name)
                except TypeError:
                    args = topic

                if args is None:
                    args = []

                if not isinstance(args, (list, tuple)):
                    args = [args]

                for story, func in context.items():
                    func(self, *args)
            inner.__doc__ = '%s: %s' % (name, ', '.join(story for story in context))
            return inner

        attrs = (('test %s' % name,
                  vow(name, context)) for name, context in contexts.items())
        return type(self.name, self.bases, dict(attrs))