import unittest import inspect import sys from unittest.mock import Mock, MagicMock, _magics class TestMockingMagicMethods(unittest.TestCase): def test_deleting_magic_methods(self): mock = Mock() self.assertFalse(hasattr(mock, '__getitem__')) mock.__getitem__ = Mock() self.assertTrue(hasattr(mock, '__getitem__')) del mock.__getitem__ self.assertFalse(hasattr(mock, '__getitem__')) def test_magicmock_del(self): mock = MagicMock() # before using getitem del mock.__getitem__ self.assertRaises(TypeError, lambda: mock['foo']) mock = MagicMock() # this time use it first mock['foo'] del mock.__getitem__ self.assertRaises(TypeError, lambda: mock['foo']) def test_magic_method_wrapping(self): mock = Mock() def f(self, name): return self, 'fish' mock.__getitem__ = f self.assertIsNot(mock.__getitem__, f) self.assertEqual(mock['foo'], (mock, 'fish')) self.assertEqual(mock.__getitem__('foo'), (mock, 'fish')) mock.__getitem__ = mock self.assertIs(mock.__getitem__, mock) def test_magic_methods_isolated_between_mocks(self): mock1 = Mock() mock2 = Mock() mock1.__iter__ = Mock(return_value=iter([])) self.assertEqual(list(mock1), []) self.assertRaises(TypeError, lambda: list(mock2)) def test_repr(self): mock = Mock() self.assertEqual(repr(mock), "" % id(mock)) mock.__repr__ = lambda s: 'foo' self.assertEqual(repr(mock), 'foo') def test_str(self): mock = Mock() self.assertEqual(str(mock), object.__str__(mock)) mock.__str__ = lambda s: 'foo' self.assertEqual(str(mock), 'foo') def test_dict_methods(self): mock = Mock() self.assertRaises(TypeError, lambda: mock['foo']) def _del(): del mock['foo'] def _set(): mock['foo'] = 3 self.assertRaises(TypeError, _del) self.assertRaises(TypeError, _set) _dict = {} def getitem(s, name): return _dict[name] def setitem(s, name, value): _dict[name] = value def delitem(s, name): del _dict[name] mock.__setitem__ = setitem mock.__getitem__ = getitem mock.__delitem__ = delitem self.assertRaises(KeyError, lambda: mock['foo']) mock['foo'] = 'bar' self.assertEqual(_dict, {'foo': 'bar'}) self.assertEqual(mock['foo'], 'bar') del mock['foo'] self.assertEqual(_dict, {}) def test_numeric(self): original = mock = Mock() mock.value = 0 self.assertRaises(TypeError, lambda: mock + 3) def add(self, other): mock.value += other return self mock.__add__ = add self.assertEqual(mock + 3, mock) self.assertEqual(mock.value, 3) del mock.__add__ def iadd(mock): mock += 3 self.assertRaises(TypeError, iadd, mock) mock.__iadd__ = add mock += 6 self.assertEqual(mock, original) self.assertEqual(mock.value, 9) self.assertRaises(TypeError, lambda: 3 + mock) mock.__radd__ = add self.assertEqual(7 + mock, mock) self.assertEqual(mock.value, 16) def test_hash(self): mock = Mock() # test delegation self.assertEqual(hash(mock), Mock.__hash__(mock)) def _hash(s): return 3 mock.__hash__ = _hash self.assertEqual(hash(mock), 3) def test_nonzero(self): m = Mock() self.assertTrue(bool(m)) m.__bool__ = lambda s: False self.assertFalse(bool(m)) def test_comparison(self): mock = Mock() def comp(s, o): return True mock.__lt__ = mock.__gt__ = mock.__le__ = mock.__ge__ = comp self. assertTrue(mock < 3) self. assertTrue(mock > 3) self. assertTrue(mock <= 3) self. assertTrue(mock >= 3) self.assertRaises(TypeError, lambda: MagicMock() < object()) self.assertRaises(TypeError, lambda: object() < MagicMock()) self.assertRaises(TypeError, lambda: MagicMock() < MagicMock()) self.assertRaises(TypeError, lambda: MagicMock() > object()) self.assertRaises(TypeError, lambda: object() > MagicMock()) self.assertRaises(TypeError, lambda: MagicMock() > MagicMock()) self.assertRaises(TypeError, lambda: MagicMock() <= object()) self.assertRaises(TypeError, lambda: object() <= MagicMock()) self.assertRaises(TypeError, lambda: MagicMock() <= MagicMock()) self.assertRaises(TypeError, lambda: MagicMock() >= object()) self.assertRaises(TypeError, lambda: object() >= MagicMock()) self.assertRaises(TypeError, lambda: MagicMock() >= MagicMock()) def test_equality(self): for mock in Mock(), MagicMock(): self.assertEqual(mock == mock, True) self.assertIsInstance(mock == mock, bool) self.assertEqual(mock != mock, False) self.assertIsInstance(mock != mock, bool) self.assertEqual(mock == object(), False) self.assertEqual(mock != object(), True) def eq(self, other): return other == 3 mock.__eq__ = eq self.assertTrue(mock == 3) self.assertFalse(mock == 4) def ne(self, other): return other == 3 mock.__ne__ = ne self.assertTrue(mock != 3) self.assertFalse(mock != 4) mock = MagicMock() mock.__eq__.return_value = True self.assertIsInstance(mock == 3, bool) self.assertEqual(mock == 3, True) mock.__ne__.return_value = False self.assertIsInstance(mock != 3, bool) self.assertEqual(mock != 3, False) def test_len_contains_iter(self): mock = Mock() self.assertRaises(TypeError, len, mock) self.assertRaises(TypeError, iter, mock) self.assertRaises(TypeError, lambda: 'foo' in mock) mock.__len__ = lambda s: 6 self.assertEqual(len(mock), 6) mock.__contains__ = lambda s, o: o == 3 self.assertIn(3, mock) self.assertNotIn(6, mock) mock.__iter__ = lambda s: iter('foobarbaz') self.assertEqual(list(mock), list('foobarbaz')) def test_magicmock(self): mock = MagicMock() mock.__iter__.return_value = iter([1, 2, 3]) self.assertEqual(list(mock), [1, 2, 3]) getattr(mock, '__bool__').return_value = False self.assertFalse(hasattr(mock, '__nonzero__')) self.assertFalse(bool(mock)) for entry in _magics: self.assertTrue(hasattr(mock, entry)) self.assertFalse(hasattr(mock, '__imaginery__')) def test_magic_mock_equality(self): mock = MagicMock() self.assertIsInstance(mock == object(), bool) self.assertIsInstance(mock != object(), bool) self.assertEqual(mock == object(), False) self.assertEqual(mock != object(), True) self.assertEqual(mock == mock, True) self.assertEqual(mock != mock, False) def test_magicmock_defaults(self): mock = MagicMock() self.assertEqual(int(mock), 1) self.assertEqual(complex(mock), 1j) self.assertEqual(float(mock), 1.0) self.assertNotIn(object(), mock) self.assertEqual(len(mock), 0) self.assertEqual(list(mock), []) self.assertEqual(hash(mock), object.__hash__(mock)) self.assertEqual(str(mock), object.__str__(mock)) self.assertTrue(bool(mock)) # in Python 3 oct and hex use __index__ # so these tests are for __index__ in py3k self.assertEqual(oct(mock), '0o1') self.assertEqual(hex(mock), '0x1') # how to test __sizeof__ ? def test_magic_methods_and_spec(self): class Iterable(object): def __iter__(self): pass mock = Mock(spec=Iterable) self.assertRaises(AttributeError, lambda: mock.__iter__) mock.__iter__ = Mock(return_value=iter([])) self.assertEqual(list(mock), []) class NonIterable(object): pass mock = Mock(spec=NonIterable) self.assertRaises(AttributeError, lambda: mock.__iter__) def set_int(): mock.__int__ = Mock(return_value=iter([])) self.assertRaises(AttributeError, set_int) mock = MagicMock(spec=Iterable) self.assertEqual(list(mock), []) self.assertRaises(AttributeError, set_int) def test_magic_methods_and_spec_set(self): class Iterable(object): def __iter__(self): pass mock = Mock(spec_set=Iterable) self.assertRaises(AttributeError, lambda: mock.__iter__) mock.__iter__ = Mock(return_value=iter([])) self.assertEqual(list(mock), []) class NonIterable(object): pass mock = Mock(spec_set=NonIterable) self.assertRaises(AttributeError, lambda: mock.__iter__) def set_int(): mock.__int__ = Mock(return_value=iter([])) self.assertRaises(AttributeError, set_int) mock = MagicMock(spec_set=Iterable) self.assertEqual(list(mock), []) self.assertRaises(AttributeError, set_int) def test_setting_unsupported_magic_method(self): mock = MagicMock() def set_setattr(): mock.__setattr__ = lambda self, name: None self.assertRaisesRegex(AttributeError, "Attempting to set unsupported magic method '__setattr__'.", set_setattr ) def test_attributes_and_return_value(self): mock = MagicMock() attr = mock.foo def _get_type(obj): # the type of every mock (or magicmock) is a custom subclass # so the real type is the second in the mro return type(obj).__mro__[1] self.assertEqual(_get_type(attr), MagicMock) returned = mock() self.assertEqual(_get_type(returned), MagicMock) def test_magic_methods_are_magic_mocks(self): mock = MagicMock() self.assertIsInstance(mock.__getitem__, MagicMock) mock[1][2].__getitem__.return_value = 3 self.assertEqual(mock[1][2][3], 3) def test_magic_method_reset_mock(self): mock = MagicMock() str(mock) self.assertTrue(mock.__str__.called) mock.reset_mock() self.assertFalse(mock.__str__.called) def test_dir(self): # overriding the default implementation for mock in Mock(), MagicMock(): def _dir(self): return ['foo'] mock.__dir__ = _dir self.assertEqual(dir(mock), ['foo']) @unittest.skipIf('PyPy' in sys.version, "This fails differently on pypy") def test_bound_methods(self): m = Mock() # XXXX should this be an expected failure instead? # this seems like it should work, but is hard to do without introducing # other api inconsistencies. Failure message could be better though. m.__iter__ = [3].__iter__ self.assertRaises(TypeError, iter, m) def test_magic_method_type(self): class Foo(MagicMock): pass foo = Foo() self.assertIsInstance(foo.__int__, Foo) def test_descriptor_from_class(self): m = MagicMock() type(m).__str__.return_value = 'foo' self.assertEqual(str(m), 'foo') def test_iterable_as_iter_return_value(self): m = MagicMock() m.__iter__.return_value = [1, 2, 3] self.assertEqual(list(m), [1, 2, 3]) self.assertEqual(list(m), [1, 2, 3]) m.__iter__.return_value = iter([4, 5, 6]) self.assertEqual(list(m), [4, 5, 6]) self.assertEqual(list(m), []) if __name__ == '__main__': unittest.main()