test_design_patterns.py

import unittest

from monty.design_patterns import cached_class, singleton


class SingletonTest(unittest.TestCase):
    def test_singleton(self):
        @singleton
        class A:
            pass

        a1 = A()
        a2 = A()

        self.assertEqual(id(a1), id(a2))


@cached_class
class A:
    def __init__(self, val):
        self.val = val

    def __eq__(self, other):
        return self.val == other.val

    def __getinitargs__(self):
        return (self.val,)

    def __getnewargs__(self):
        return (self.val,)


class CachedClassTest(unittest.TestCase):
    def test_cached_class(self):
        a1a = A(1)
        a1b = A(1)
        a2 = A(2)

        self.assertEqual(id(a1a), id(a1b))
        self.assertNotEqual(id(a1a), id(a2))

    # def test_pickle(self):
    #     a = A(2)
    #     o = pickle.dumps(a)
    #     self.assertEqual(a, pickle.loads(o))


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