Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 1 | import types |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 2 | import unittest |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 3 | |
| 4 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 5 | class Test(unittest.TestCase): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 6 | def test_init_subclass(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 7 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 8 | initialized = False |
| 9 | |
| 10 | def __init_subclass__(cls): |
| 11 | super().__init_subclass__() |
| 12 | cls.initialized = True |
| 13 | |
| 14 | class B(A): |
| 15 | pass |
| 16 | |
| 17 | self.assertFalse(A.initialized) |
| 18 | self.assertTrue(B.initialized) |
| 19 | |
| 20 | def test_init_subclass_dict(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 21 | class A(dict): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 22 | initialized = False |
| 23 | |
| 24 | def __init_subclass__(cls): |
| 25 | super().__init_subclass__() |
| 26 | cls.initialized = True |
| 27 | |
| 28 | class B(A): |
| 29 | pass |
| 30 | |
| 31 | self.assertFalse(A.initialized) |
| 32 | self.assertTrue(B.initialized) |
| 33 | |
| 34 | def test_init_subclass_kwargs(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 35 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 36 | def __init_subclass__(cls, **kwargs): |
| 37 | cls.kwargs = kwargs |
| 38 | |
| 39 | class B(A, x=3): |
| 40 | pass |
| 41 | |
| 42 | self.assertEqual(B.kwargs, dict(x=3)) |
| 43 | |
| 44 | def test_init_subclass_error(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 45 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 46 | def __init_subclass__(cls): |
| 47 | raise RuntimeError |
| 48 | |
| 49 | with self.assertRaises(RuntimeError): |
| 50 | class B(A): |
| 51 | pass |
| 52 | |
| 53 | def test_init_subclass_wrong(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 54 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 55 | def __init_subclass__(cls, whatever): |
| 56 | pass |
| 57 | |
| 58 | with self.assertRaises(TypeError): |
| 59 | class B(A): |
| 60 | pass |
| 61 | |
| 62 | def test_init_subclass_skipped(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 63 | class BaseWithInit: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 64 | def __init_subclass__(cls, **kwargs): |
| 65 | super().__init_subclass__(**kwargs) |
| 66 | cls.initialized = cls |
| 67 | |
| 68 | class BaseWithoutInit(BaseWithInit): |
| 69 | pass |
| 70 | |
| 71 | class A(BaseWithoutInit): |
| 72 | pass |
| 73 | |
| 74 | self.assertIs(A.initialized, A) |
| 75 | self.assertIs(BaseWithoutInit.initialized, BaseWithoutInit) |
| 76 | |
| 77 | def test_init_subclass_diamond(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 78 | class Base: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 79 | def __init_subclass__(cls, **kwargs): |
| 80 | super().__init_subclass__(**kwargs) |
| 81 | cls.calls = [] |
| 82 | |
| 83 | class Left(Base): |
| 84 | pass |
| 85 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 86 | class Middle: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 87 | def __init_subclass__(cls, middle, **kwargs): |
| 88 | super().__init_subclass__(**kwargs) |
| 89 | cls.calls += [middle] |
| 90 | |
| 91 | class Right(Base): |
| 92 | def __init_subclass__(cls, right="right", **kwargs): |
| 93 | super().__init_subclass__(**kwargs) |
| 94 | cls.calls += [right] |
| 95 | |
| 96 | class A(Left, Middle, Right, middle="middle"): |
| 97 | pass |
| 98 | |
| 99 | self.assertEqual(A.calls, ["right", "middle"]) |
| 100 | self.assertEqual(Left.calls, []) |
| 101 | self.assertEqual(Right.calls, []) |
| 102 | |
| 103 | def test_set_name(self): |
| 104 | class Descriptor: |
| 105 | def __set_name__(self, owner, name): |
| 106 | self.owner = owner |
| 107 | self.name = name |
| 108 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 109 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 110 | d = Descriptor() |
| 111 | |
| 112 | self.assertEqual(A.d.name, "d") |
| 113 | self.assertIs(A.d.owner, A) |
| 114 | |
| 115 | def test_set_name_metaclass(self): |
| 116 | class Meta(type): |
| 117 | def __new__(cls, name, bases, ns): |
| 118 | ret = super().__new__(cls, name, bases, ns) |
| 119 | self.assertEqual(ret.d.name, "d") |
| 120 | self.assertIs(ret.d.owner, ret) |
| 121 | return 0 |
| 122 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 123 | class Descriptor: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 124 | def __set_name__(self, owner, name): |
| 125 | self.owner = owner |
| 126 | self.name = name |
| 127 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 128 | class A(metaclass=Meta): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 129 | d = Descriptor() |
| 130 | self.assertEqual(A, 0) |
| 131 | |
| 132 | def test_set_name_error(self): |
| 133 | class Descriptor: |
| 134 | def __set_name__(self, owner, name): |
Serhiy Storchaka | d5d32d2 | 2016-10-21 17:13:31 +0300 | [diff] [blame] | 135 | 1/0 |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 136 | |
Serhiy Storchaka | d5d32d2 | 2016-10-21 17:13:31 +0300 | [diff] [blame] | 137 | with self.assertRaises(RuntimeError) as cm: |
| 138 | class NotGoingToWork: |
| 139 | attr = Descriptor() |
| 140 | |
| 141 | exc = cm.exception |
| 142 | self.assertRegex(str(exc), r'\bNotGoingToWork\b') |
| 143 | self.assertRegex(str(exc), r'\battr\b') |
| 144 | self.assertRegex(str(exc), r'\bDescriptor\b') |
| 145 | self.assertIsInstance(exc.__cause__, ZeroDivisionError) |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 146 | |
| 147 | def test_set_name_wrong(self): |
| 148 | class Descriptor: |
| 149 | def __set_name__(self): |
| 150 | pass |
| 151 | |
Serhiy Storchaka | d5d32d2 | 2016-10-21 17:13:31 +0300 | [diff] [blame] | 152 | with self.assertRaises(RuntimeError) as cm: |
| 153 | class NotGoingToWork: |
| 154 | attr = Descriptor() |
| 155 | |
| 156 | exc = cm.exception |
| 157 | self.assertRegex(str(exc), r'\bNotGoingToWork\b') |
| 158 | self.assertRegex(str(exc), r'\battr\b') |
| 159 | self.assertRegex(str(exc), r'\bDescriptor\b') |
| 160 | self.assertIsInstance(exc.__cause__, TypeError) |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 161 | |
Serhiy Storchaka | afd02a4 | 2016-09-21 15:54:59 +0300 | [diff] [blame] | 162 | def test_set_name_lookup(self): |
| 163 | resolved = [] |
| 164 | class NonDescriptor: |
| 165 | def __getattr__(self, name): |
| 166 | resolved.append(name) |
| 167 | |
| 168 | class A: |
| 169 | d = NonDescriptor() |
| 170 | |
| 171 | self.assertNotIn('__set_name__', resolved, |
| 172 | '__set_name__ is looked up in instance dict') |
| 173 | |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 174 | def test_set_name_init_subclass(self): |
| 175 | class Descriptor: |
| 176 | def __set_name__(self, owner, name): |
| 177 | self.owner = owner |
| 178 | self.name = name |
| 179 | |
| 180 | class Meta(type): |
| 181 | def __new__(cls, name, bases, ns): |
| 182 | self = super().__new__(cls, name, bases, ns) |
| 183 | self.meta_owner = self.owner |
| 184 | self.meta_name = self.name |
| 185 | return self |
| 186 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 187 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 188 | def __init_subclass__(cls): |
| 189 | cls.owner = cls.d.owner |
| 190 | cls.name = cls.d.name |
| 191 | |
| 192 | class B(A, metaclass=Meta): |
| 193 | d = Descriptor() |
| 194 | |
| 195 | self.assertIs(B.owner, B) |
| 196 | self.assertEqual(B.name, 'd') |
| 197 | self.assertIs(B.meta_owner, B) |
| 198 | self.assertEqual(B.name, 'd') |
| 199 | |
Serhiy Storchaka | 9ec0772 | 2016-11-29 09:54:17 +0200 | [diff] [blame] | 200 | def test_set_name_modifying_dict(self): |
| 201 | notified = [] |
| 202 | class Descriptor: |
| 203 | def __set_name__(self, owner, name): |
| 204 | setattr(owner, name + 'x', None) |
| 205 | notified.append(name) |
| 206 | |
| 207 | class A: |
| 208 | a = Descriptor() |
| 209 | b = Descriptor() |
| 210 | c = Descriptor() |
| 211 | d = Descriptor() |
| 212 | e = Descriptor() |
| 213 | |
| 214 | self.assertCountEqual(notified, ['a', 'b', 'c', 'd', 'e']) |
| 215 | |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 216 | def test_errors(self): |
| 217 | class MyMeta(type): |
| 218 | pass |
| 219 | |
| 220 | with self.assertRaises(TypeError): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 221 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 222 | pass |
| 223 | |
| 224 | with self.assertRaises(TypeError): |
| 225 | types.new_class("MyClass", (object,), |
| 226 | dict(metaclass=MyMeta, otherarg=1)) |
| 227 | types.prepare_class("MyClass", (object,), |
| 228 | dict(metaclass=MyMeta, otherarg=1)) |
| 229 | |
| 230 | class MyMeta(type): |
| 231 | def __init__(self, name, bases, namespace, otherarg): |
| 232 | super().__init__(name, bases, namespace) |
| 233 | |
| 234 | with self.assertRaises(TypeError): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 235 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 236 | pass |
| 237 | |
| 238 | class MyMeta(type): |
| 239 | def __new__(cls, name, bases, namespace, otherarg): |
| 240 | return super().__new__(cls, name, bases, namespace) |
| 241 | |
| 242 | def __init__(self, name, bases, namespace, otherarg): |
| 243 | super().__init__(name, bases, namespace) |
| 244 | self.otherarg = otherarg |
| 245 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 246 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 247 | pass |
| 248 | |
| 249 | self.assertEqual(MyClass.otherarg, 1) |
| 250 | |
| 251 | def test_errors_changed_pep487(self): |
| 252 | # These tests failed before Python 3.6, PEP 487 |
| 253 | class MyMeta(type): |
| 254 | def __new__(cls, name, bases, namespace): |
| 255 | return super().__new__(cls, name=name, bases=bases, |
| 256 | dict=namespace) |
| 257 | |
| 258 | with self.assertRaises(TypeError): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 259 | class MyClass(metaclass=MyMeta): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 260 | pass |
| 261 | |
| 262 | class MyMeta(type): |
| 263 | def __new__(cls, name, bases, namespace, otherarg): |
| 264 | self = super().__new__(cls, name, bases, namespace) |
| 265 | self.otherarg = otherarg |
| 266 | return self |
| 267 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 268 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 269 | pass |
| 270 | |
| 271 | self.assertEqual(MyClass.otherarg, 1) |
| 272 | |
| 273 | def test_type(self): |
| 274 | t = type('NewClass', (object,), {}) |
| 275 | self.assertIsInstance(t, type) |
| 276 | self.assertEqual(t.__name__, 'NewClass') |
| 277 | |
| 278 | with self.assertRaises(TypeError): |
| 279 | type(name='NewClass', bases=(object,), dict={}) |
| 280 | |
| 281 | |
| 282 | if __name__ == "__main__": |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 283 | unittest.main() |