testmagicmethods.py 14 KB

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  1. import unittest
  2. import inspect
  3. import sys
  4. from unittest.mock import Mock, MagicMock, _magics
  5. class TestMockingMagicMethods(unittest.TestCase):
  6. def test_deleting_magic_methods(self):
  7. mock = Mock()
  8. self.assertFalse(hasattr(mock, '__getitem__'))
  9. mock.__getitem__ = Mock()
  10. self.assertTrue(hasattr(mock, '__getitem__'))
  11. del mock.__getitem__
  12. self.assertFalse(hasattr(mock, '__getitem__'))
  13. def test_magicmock_del(self):
  14. mock = MagicMock()
  15. # before using getitem
  16. del mock.__getitem__
  17. self.assertRaises(TypeError, lambda: mock['foo'])
  18. mock = MagicMock()
  19. # this time use it first
  20. mock['foo']
  21. del mock.__getitem__
  22. self.assertRaises(TypeError, lambda: mock['foo'])
  23. def test_magic_method_wrapping(self):
  24. mock = Mock()
  25. def f(self, name):
  26. return self, 'fish'
  27. mock.__getitem__ = f
  28. self.assertIsNot(mock.__getitem__, f)
  29. self.assertEqual(mock['foo'], (mock, 'fish'))
  30. self.assertEqual(mock.__getitem__('foo'), (mock, 'fish'))
  31. mock.__getitem__ = mock
  32. self.assertIs(mock.__getitem__, mock)
  33. def test_magic_methods_isolated_between_mocks(self):
  34. mock1 = Mock()
  35. mock2 = Mock()
  36. mock1.__iter__ = Mock(return_value=iter([]))
  37. self.assertEqual(list(mock1), [])
  38. self.assertRaises(TypeError, lambda: list(mock2))
  39. def test_repr(self):
  40. mock = Mock()
  41. self.assertEqual(repr(mock), "<Mock id='%s'>" % id(mock))
  42. mock.__repr__ = lambda s: 'foo'
  43. self.assertEqual(repr(mock), 'foo')
  44. def test_str(self):
  45. mock = Mock()
  46. self.assertEqual(str(mock), object.__str__(mock))
  47. mock.__str__ = lambda s: 'foo'
  48. self.assertEqual(str(mock), 'foo')
  49. def test_dict_methods(self):
  50. mock = Mock()
  51. self.assertRaises(TypeError, lambda: mock['foo'])
  52. def _del():
  53. del mock['foo']
  54. def _set():
  55. mock['foo'] = 3
  56. self.assertRaises(TypeError, _del)
  57. self.assertRaises(TypeError, _set)
  58. _dict = {}
  59. def getitem(s, name):
  60. return _dict[name]
  61. def setitem(s, name, value):
  62. _dict[name] = value
  63. def delitem(s, name):
  64. del _dict[name]
  65. mock.__setitem__ = setitem
  66. mock.__getitem__ = getitem
  67. mock.__delitem__ = delitem
  68. self.assertRaises(KeyError, lambda: mock['foo'])
  69. mock['foo'] = 'bar'
  70. self.assertEqual(_dict, {'foo': 'bar'})
  71. self.assertEqual(mock['foo'], 'bar')
  72. del mock['foo']
  73. self.assertEqual(_dict, {})
  74. def test_numeric(self):
  75. original = mock = Mock()
  76. mock.value = 0
  77. self.assertRaises(TypeError, lambda: mock + 3)
  78. def add(self, other):
  79. mock.value += other
  80. return self
  81. mock.__add__ = add
  82. self.assertEqual(mock + 3, mock)
  83. self.assertEqual(mock.value, 3)
  84. del mock.__add__
  85. def iadd(mock):
  86. mock += 3
  87. self.assertRaises(TypeError, iadd, mock)
  88. mock.__iadd__ = add
  89. mock += 6
  90. self.assertEqual(mock, original)
  91. self.assertEqual(mock.value, 9)
  92. self.assertRaises(TypeError, lambda: 3 + mock)
  93. mock.__radd__ = add
  94. self.assertEqual(7 + mock, mock)
  95. self.assertEqual(mock.value, 16)
  96. def test_division(self):
  97. original = mock = Mock()
  98. mock.value = 32
  99. self.assertRaises(TypeError, lambda: mock / 2)
  100. def truediv(self, other):
  101. mock.value /= other
  102. return self
  103. mock.__truediv__ = truediv
  104. self.assertEqual(mock / 2, mock)
  105. self.assertEqual(mock.value, 16)
  106. del mock.__truediv__
  107. def itruediv(mock):
  108. mock /= 4
  109. self.assertRaises(TypeError, itruediv, mock)
  110. mock.__itruediv__ = truediv
  111. mock /= 8
  112. self.assertEqual(mock, original)
  113. self.assertEqual(mock.value, 2)
  114. self.assertRaises(TypeError, lambda: 8 / mock)
  115. mock.__rtruediv__ = truediv
  116. self.assertEqual(0.5 / mock, mock)
  117. self.assertEqual(mock.value, 4)
  118. def test_hash(self):
  119. mock = Mock()
  120. # test delegation
  121. self.assertEqual(hash(mock), Mock.__hash__(mock))
  122. def _hash(s):
  123. return 3
  124. mock.__hash__ = _hash
  125. self.assertEqual(hash(mock), 3)
  126. def test_nonzero(self):
  127. m = Mock()
  128. self.assertTrue(bool(m))
  129. m.__bool__ = lambda s: False
  130. self.assertFalse(bool(m))
  131. def test_comparison(self):
  132. mock = Mock()
  133. def comp(s, o):
  134. return True
  135. mock.__lt__ = mock.__gt__ = mock.__le__ = mock.__ge__ = comp
  136. self. assertTrue(mock < 3)
  137. self. assertTrue(mock > 3)
  138. self. assertTrue(mock <= 3)
  139. self. assertTrue(mock >= 3)
  140. self.assertRaises(TypeError, lambda: MagicMock() < object())
  141. self.assertRaises(TypeError, lambda: object() < MagicMock())
  142. self.assertRaises(TypeError, lambda: MagicMock() < MagicMock())
  143. self.assertRaises(TypeError, lambda: MagicMock() > object())
  144. self.assertRaises(TypeError, lambda: object() > MagicMock())
  145. self.assertRaises(TypeError, lambda: MagicMock() > MagicMock())
  146. self.assertRaises(TypeError, lambda: MagicMock() <= object())
  147. self.assertRaises(TypeError, lambda: object() <= MagicMock())
  148. self.assertRaises(TypeError, lambda: MagicMock() <= MagicMock())
  149. self.assertRaises(TypeError, lambda: MagicMock() >= object())
  150. self.assertRaises(TypeError, lambda: object() >= MagicMock())
  151. self.assertRaises(TypeError, lambda: MagicMock() >= MagicMock())
  152. def test_equality(self):
  153. for mock in Mock(), MagicMock():
  154. self.assertEqual(mock == mock, True)
  155. self.assertIsInstance(mock == mock, bool)
  156. self.assertEqual(mock != mock, False)
  157. self.assertIsInstance(mock != mock, bool)
  158. self.assertEqual(mock == object(), False)
  159. self.assertEqual(mock != object(), True)
  160. def eq(self, other):
  161. return other == 3
  162. mock.__eq__ = eq
  163. self.assertTrue(mock == 3)
  164. self.assertFalse(mock == 4)
  165. def ne(self, other):
  166. return other == 3
  167. mock.__ne__ = ne
  168. self.assertTrue(mock != 3)
  169. self.assertFalse(mock != 4)
  170. mock = MagicMock()
  171. mock.__eq__.return_value = True
  172. self.assertIsInstance(mock == 3, bool)
  173. self.assertEqual(mock == 3, True)
  174. mock.__ne__.return_value = False
  175. self.assertIsInstance(mock != 3, bool)
  176. self.assertEqual(mock != 3, False)
  177. def test_len_contains_iter(self):
  178. mock = Mock()
  179. self.assertRaises(TypeError, len, mock)
  180. self.assertRaises(TypeError, iter, mock)
  181. self.assertRaises(TypeError, lambda: 'foo' in mock)
  182. mock.__len__ = lambda s: 6
  183. self.assertEqual(len(mock), 6)
  184. mock.__contains__ = lambda s, o: o == 3
  185. self.assertIn(3, mock)
  186. self.assertNotIn(6, mock)
  187. mock.__iter__ = lambda s: iter('foobarbaz')
  188. self.assertEqual(list(mock), list('foobarbaz'))
  189. def test_magicmock(self):
  190. mock = MagicMock()
  191. mock.__iter__.return_value = iter([1, 2, 3])
  192. self.assertEqual(list(mock), [1, 2, 3])
  193. getattr(mock, '__bool__').return_value = False
  194. self.assertFalse(hasattr(mock, '__nonzero__'))
  195. self.assertFalse(bool(mock))
  196. for entry in _magics:
  197. self.assertTrue(hasattr(mock, entry))
  198. self.assertFalse(hasattr(mock, '__imaginery__'))
  199. def test_magic_mock_equality(self):
  200. mock = MagicMock()
  201. self.assertIsInstance(mock == object(), bool)
  202. self.assertIsInstance(mock != object(), bool)
  203. self.assertEqual(mock == object(), False)
  204. self.assertEqual(mock != object(), True)
  205. self.assertEqual(mock == mock, True)
  206. self.assertEqual(mock != mock, False)
  207. def test_magicmock_defaults(self):
  208. mock = MagicMock()
  209. self.assertEqual(int(mock), 1)
  210. self.assertEqual(complex(mock), 1j)
  211. self.assertEqual(float(mock), 1.0)
  212. self.assertNotIn(object(), mock)
  213. self.assertEqual(len(mock), 0)
  214. self.assertEqual(list(mock), [])
  215. self.assertEqual(hash(mock), object.__hash__(mock))
  216. self.assertEqual(str(mock), object.__str__(mock))
  217. self.assertTrue(bool(mock))
  218. # in Python 3 oct and hex use __index__
  219. # so these tests are for __index__ in py3k
  220. self.assertEqual(oct(mock), '0o1')
  221. self.assertEqual(hex(mock), '0x1')
  222. # how to test __sizeof__ ?
  223. def test_magic_methods_and_spec(self):
  224. class Iterable(object):
  225. def __iter__(self):
  226. pass
  227. mock = Mock(spec=Iterable)
  228. self.assertRaises(AttributeError, lambda: mock.__iter__)
  229. mock.__iter__ = Mock(return_value=iter([]))
  230. self.assertEqual(list(mock), [])
  231. class NonIterable(object):
  232. pass
  233. mock = Mock(spec=NonIterable)
  234. self.assertRaises(AttributeError, lambda: mock.__iter__)
  235. def set_int():
  236. mock.__int__ = Mock(return_value=iter([]))
  237. self.assertRaises(AttributeError, set_int)
  238. mock = MagicMock(spec=Iterable)
  239. self.assertEqual(list(mock), [])
  240. self.assertRaises(AttributeError, set_int)
  241. def test_magic_methods_and_spec_set(self):
  242. class Iterable(object):
  243. def __iter__(self):
  244. pass
  245. mock = Mock(spec_set=Iterable)
  246. self.assertRaises(AttributeError, lambda: mock.__iter__)
  247. mock.__iter__ = Mock(return_value=iter([]))
  248. self.assertEqual(list(mock), [])
  249. class NonIterable(object):
  250. pass
  251. mock = Mock(spec_set=NonIterable)
  252. self.assertRaises(AttributeError, lambda: mock.__iter__)
  253. def set_int():
  254. mock.__int__ = Mock(return_value=iter([]))
  255. self.assertRaises(AttributeError, set_int)
  256. mock = MagicMock(spec_set=Iterable)
  257. self.assertEqual(list(mock), [])
  258. self.assertRaises(AttributeError, set_int)
  259. def test_setting_unsupported_magic_method(self):
  260. mock = MagicMock()
  261. def set_setattr():
  262. mock.__setattr__ = lambda self, name: None
  263. self.assertRaisesRegex(AttributeError,
  264. "Attempting to set unsupported magic method '__setattr__'.",
  265. set_setattr
  266. )
  267. def test_attributes_and_return_value(self):
  268. mock = MagicMock()
  269. attr = mock.foo
  270. def _get_type(obj):
  271. # the type of every mock (or magicmock) is a custom subclass
  272. # so the real type is the second in the mro
  273. return type(obj).__mro__[1]
  274. self.assertEqual(_get_type(attr), MagicMock)
  275. returned = mock()
  276. self.assertEqual(_get_type(returned), MagicMock)
  277. def test_magic_methods_are_magic_mocks(self):
  278. mock = MagicMock()
  279. self.assertIsInstance(mock.__getitem__, MagicMock)
  280. mock[1][2].__getitem__.return_value = 3
  281. self.assertEqual(mock[1][2][3], 3)
  282. def test_magic_method_reset_mock(self):
  283. mock = MagicMock()
  284. str(mock)
  285. self.assertTrue(mock.__str__.called)
  286. mock.reset_mock()
  287. self.assertFalse(mock.__str__.called)
  288. def test_dir(self):
  289. # overriding the default implementation
  290. for mock in Mock(), MagicMock():
  291. def _dir(self):
  292. return ['foo']
  293. mock.__dir__ = _dir
  294. self.assertEqual(dir(mock), ['foo'])
  295. @unittest.skipIf('PyPy' in sys.version, "This fails differently on pypy")
  296. def test_bound_methods(self):
  297. m = Mock()
  298. # XXXX should this be an expected failure instead?
  299. # this seems like it should work, but is hard to do without introducing
  300. # other api inconsistencies. Failure message could be better though.
  301. m.__iter__ = [3].__iter__
  302. self.assertRaises(TypeError, iter, m)
  303. def test_magic_method_type(self):
  304. class Foo(MagicMock):
  305. pass
  306. foo = Foo()
  307. self.assertIsInstance(foo.__int__, Foo)
  308. def test_descriptor_from_class(self):
  309. m = MagicMock()
  310. type(m).__str__.return_value = 'foo'
  311. self.assertEqual(str(m), 'foo')
  312. def test_iterable_as_iter_return_value(self):
  313. m = MagicMock()
  314. m.__iter__.return_value = [1, 2, 3]
  315. self.assertEqual(list(m), [1, 2, 3])
  316. self.assertEqual(list(m), [1, 2, 3])
  317. m.__iter__.return_value = iter([4, 5, 6])
  318. self.assertEqual(list(m), [4, 5, 6])
  319. self.assertEqual(list(m), [])
  320. def test_matmul(self):
  321. m = MagicMock()
  322. self.assertIsInstance(m @ 1, MagicMock)
  323. m.__matmul__.return_value = 42
  324. m.__rmatmul__.return_value = 666
  325. m.__imatmul__.return_value = 24
  326. self.assertEqual(m @ 1, 42)
  327. self.assertEqual(1 @ m, 666)
  328. m @= 24
  329. self.assertEqual(m, 24)
  330. def test_divmod_and_rdivmod(self):
  331. m = MagicMock()
  332. self.assertIsInstance(divmod(5, m), MagicMock)
  333. m.__divmod__.return_value = (2, 1)
  334. self.assertEqual(divmod(m, 2), (2, 1))
  335. m = MagicMock()
  336. foo = divmod(2, m)
  337. self.assertIsInstance(foo, MagicMock)
  338. foo_direct = m.__divmod__(2)
  339. self.assertIsInstance(foo_direct, MagicMock)
  340. bar = divmod(m, 2)
  341. self.assertIsInstance(bar, MagicMock)
  342. bar_direct = m.__rdivmod__(2)
  343. self.assertIsInstance(bar_direct, MagicMock)
  344. # http://bugs.python.org/issue23310
  345. # Check if you can change behaviour of magic methds in MagicMock init
  346. def test_magic_in_initialization(self):
  347. m = MagicMock(**{'__str__.return_value': "12"})
  348. self.assertEqual(str(m), "12")
  349. def test_changing_magic_set_in_initialization(self):
  350. m = MagicMock(**{'__str__.return_value': "12"})
  351. m.__str__.return_value = "13"
  352. self.assertEqual(str(m), "13")
  353. m = MagicMock(**{'__str__.return_value': "12"})
  354. m.configure_mock(**{'__str__.return_value': "14"})
  355. self.assertEqual(str(m), "14")
  356. if __name__ == '__main__':
  357. unittest.main()