Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 1 | import sys |
| 2 | import types |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 3 | import unittest |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 4 | |
| 5 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 6 | class Test(unittest.TestCase): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 7 | def test_init_subclass(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 8 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 9 | initialized = False |
| 10 | |
| 11 | def __init_subclass__(cls): |
| 12 | super().__init_subclass__() |
| 13 | cls.initialized = True |
| 14 | |
| 15 | class B(A): |
| 16 | pass |
| 17 | |
| 18 | self.assertFalse(A.initialized) |
| 19 | self.assertTrue(B.initialized) |
| 20 | |
| 21 | def test_init_subclass_dict(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 22 | class A(dict): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 23 | initialized = False |
| 24 | |
| 25 | def __init_subclass__(cls): |
| 26 | super().__init_subclass__() |
| 27 | cls.initialized = True |
| 28 | |
| 29 | class B(A): |
| 30 | pass |
| 31 | |
| 32 | self.assertFalse(A.initialized) |
| 33 | self.assertTrue(B.initialized) |
| 34 | |
| 35 | def test_init_subclass_kwargs(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 36 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 37 | def __init_subclass__(cls, **kwargs): |
| 38 | cls.kwargs = kwargs |
| 39 | |
| 40 | class B(A, x=3): |
| 41 | pass |
| 42 | |
| 43 | self.assertEqual(B.kwargs, dict(x=3)) |
| 44 | |
| 45 | def test_init_subclass_error(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 46 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 47 | def __init_subclass__(cls): |
| 48 | raise RuntimeError |
| 49 | |
| 50 | with self.assertRaises(RuntimeError): |
| 51 | class B(A): |
| 52 | pass |
| 53 | |
| 54 | def test_init_subclass_wrong(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 55 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 56 | def __init_subclass__(cls, whatever): |
| 57 | pass |
| 58 | |
| 59 | with self.assertRaises(TypeError): |
| 60 | class B(A): |
| 61 | pass |
| 62 | |
| 63 | def test_init_subclass_skipped(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 64 | class BaseWithInit: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 65 | def __init_subclass__(cls, **kwargs): |
| 66 | super().__init_subclass__(**kwargs) |
| 67 | cls.initialized = cls |
| 68 | |
| 69 | class BaseWithoutInit(BaseWithInit): |
| 70 | pass |
| 71 | |
| 72 | class A(BaseWithoutInit): |
| 73 | pass |
| 74 | |
| 75 | self.assertIs(A.initialized, A) |
| 76 | self.assertIs(BaseWithoutInit.initialized, BaseWithoutInit) |
| 77 | |
| 78 | def test_init_subclass_diamond(self): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 79 | class Base: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 80 | def __init_subclass__(cls, **kwargs): |
| 81 | super().__init_subclass__(**kwargs) |
| 82 | cls.calls = [] |
| 83 | |
| 84 | class Left(Base): |
| 85 | pass |
| 86 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 87 | class Middle: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 88 | def __init_subclass__(cls, middle, **kwargs): |
| 89 | super().__init_subclass__(**kwargs) |
| 90 | cls.calls += [middle] |
| 91 | |
| 92 | class Right(Base): |
| 93 | def __init_subclass__(cls, right="right", **kwargs): |
| 94 | super().__init_subclass__(**kwargs) |
| 95 | cls.calls += [right] |
| 96 | |
| 97 | class A(Left, Middle, Right, middle="middle"): |
| 98 | pass |
| 99 | |
| 100 | self.assertEqual(A.calls, ["right", "middle"]) |
| 101 | self.assertEqual(Left.calls, []) |
| 102 | self.assertEqual(Right.calls, []) |
| 103 | |
| 104 | def test_set_name(self): |
| 105 | class Descriptor: |
| 106 | def __set_name__(self, owner, name): |
| 107 | self.owner = owner |
| 108 | self.name = name |
| 109 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 110 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 111 | d = Descriptor() |
| 112 | |
| 113 | self.assertEqual(A.d.name, "d") |
| 114 | self.assertIs(A.d.owner, A) |
| 115 | |
| 116 | def test_set_name_metaclass(self): |
| 117 | class Meta(type): |
| 118 | def __new__(cls, name, bases, ns): |
| 119 | ret = super().__new__(cls, name, bases, ns) |
| 120 | self.assertEqual(ret.d.name, "d") |
| 121 | self.assertIs(ret.d.owner, ret) |
| 122 | return 0 |
| 123 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 124 | class Descriptor: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 125 | def __set_name__(self, owner, name): |
| 126 | self.owner = owner |
| 127 | self.name = name |
| 128 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 129 | class A(metaclass=Meta): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 130 | d = Descriptor() |
| 131 | self.assertEqual(A, 0) |
| 132 | |
| 133 | def test_set_name_error(self): |
| 134 | class Descriptor: |
| 135 | def __set_name__(self, owner, name): |
Serhiy Storchaka | d5d32d2 | 2016-10-21 17:13:31 +0300 | [diff] [blame] | 136 | 1/0 |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 137 | |
Serhiy Storchaka | d5d32d2 | 2016-10-21 17:13:31 +0300 | [diff] [blame] | 138 | with self.assertRaises(RuntimeError) as cm: |
| 139 | class NotGoingToWork: |
| 140 | attr = Descriptor() |
| 141 | |
| 142 | exc = cm.exception |
| 143 | self.assertRegex(str(exc), r'\bNotGoingToWork\b') |
| 144 | self.assertRegex(str(exc), r'\battr\b') |
| 145 | self.assertRegex(str(exc), r'\bDescriptor\b') |
| 146 | self.assertIsInstance(exc.__cause__, ZeroDivisionError) |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 147 | |
| 148 | def test_set_name_wrong(self): |
| 149 | class Descriptor: |
| 150 | def __set_name__(self): |
| 151 | pass |
| 152 | |
Serhiy Storchaka | d5d32d2 | 2016-10-21 17:13:31 +0300 | [diff] [blame] | 153 | with self.assertRaises(RuntimeError) as cm: |
| 154 | class NotGoingToWork: |
| 155 | attr = Descriptor() |
| 156 | |
| 157 | exc = cm.exception |
| 158 | self.assertRegex(str(exc), r'\bNotGoingToWork\b') |
| 159 | self.assertRegex(str(exc), r'\battr\b') |
| 160 | self.assertRegex(str(exc), r'\bDescriptor\b') |
| 161 | self.assertIsInstance(exc.__cause__, TypeError) |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 162 | |
Serhiy Storchaka | afd02a4 | 2016-09-21 15:54:59 +0300 | [diff] [blame] | 163 | def test_set_name_lookup(self): |
| 164 | resolved = [] |
| 165 | class NonDescriptor: |
| 166 | def __getattr__(self, name): |
| 167 | resolved.append(name) |
| 168 | |
| 169 | class A: |
| 170 | d = NonDescriptor() |
| 171 | |
| 172 | self.assertNotIn('__set_name__', resolved, |
| 173 | '__set_name__ is looked up in instance dict') |
| 174 | |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 175 | def test_set_name_init_subclass(self): |
| 176 | class Descriptor: |
| 177 | def __set_name__(self, owner, name): |
| 178 | self.owner = owner |
| 179 | self.name = name |
| 180 | |
| 181 | class Meta(type): |
| 182 | def __new__(cls, name, bases, ns): |
| 183 | self = super().__new__(cls, name, bases, ns) |
| 184 | self.meta_owner = self.owner |
| 185 | self.meta_name = self.name |
| 186 | return self |
| 187 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 188 | class A: |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 189 | def __init_subclass__(cls): |
| 190 | cls.owner = cls.d.owner |
| 191 | cls.name = cls.d.name |
| 192 | |
| 193 | class B(A, metaclass=Meta): |
| 194 | d = Descriptor() |
| 195 | |
| 196 | self.assertIs(B.owner, B) |
| 197 | self.assertEqual(B.name, 'd') |
| 198 | self.assertIs(B.meta_owner, B) |
| 199 | self.assertEqual(B.name, 'd') |
| 200 | |
Serhiy Storchaka | 9ec0772 | 2016-11-29 09:54:17 +0200 | [diff] [blame] | 201 | def test_set_name_modifying_dict(self): |
| 202 | notified = [] |
| 203 | class Descriptor: |
| 204 | def __set_name__(self, owner, name): |
| 205 | setattr(owner, name + 'x', None) |
| 206 | notified.append(name) |
| 207 | |
| 208 | class A: |
| 209 | a = Descriptor() |
| 210 | b = Descriptor() |
| 211 | c = Descriptor() |
| 212 | d = Descriptor() |
| 213 | e = Descriptor() |
| 214 | |
| 215 | self.assertCountEqual(notified, ['a', 'b', 'c', 'd', 'e']) |
| 216 | |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 217 | def test_errors(self): |
| 218 | class MyMeta(type): |
| 219 | pass |
| 220 | |
| 221 | with self.assertRaises(TypeError): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 222 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 223 | pass |
| 224 | |
| 225 | with self.assertRaises(TypeError): |
| 226 | types.new_class("MyClass", (object,), |
| 227 | dict(metaclass=MyMeta, otherarg=1)) |
| 228 | types.prepare_class("MyClass", (object,), |
| 229 | dict(metaclass=MyMeta, otherarg=1)) |
| 230 | |
| 231 | class MyMeta(type): |
| 232 | def __init__(self, name, bases, namespace, otherarg): |
| 233 | super().__init__(name, bases, namespace) |
| 234 | |
| 235 | with self.assertRaises(TypeError): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 236 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 237 | pass |
| 238 | |
| 239 | class MyMeta(type): |
| 240 | def __new__(cls, name, bases, namespace, otherarg): |
| 241 | return super().__new__(cls, name, bases, namespace) |
| 242 | |
| 243 | def __init__(self, name, bases, namespace, otherarg): |
| 244 | super().__init__(name, bases, namespace) |
| 245 | self.otherarg = otherarg |
| 246 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 247 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 248 | pass |
| 249 | |
| 250 | self.assertEqual(MyClass.otherarg, 1) |
| 251 | |
| 252 | def test_errors_changed_pep487(self): |
| 253 | # These tests failed before Python 3.6, PEP 487 |
| 254 | class MyMeta(type): |
| 255 | def __new__(cls, name, bases, namespace): |
| 256 | return super().__new__(cls, name=name, bases=bases, |
| 257 | dict=namespace) |
| 258 | |
| 259 | with self.assertRaises(TypeError): |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 260 | class MyClass(metaclass=MyMeta): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 261 | pass |
| 262 | |
| 263 | class MyMeta(type): |
| 264 | def __new__(cls, name, bases, namespace, otherarg): |
| 265 | self = super().__new__(cls, name, bases, namespace) |
| 266 | self.otherarg = otherarg |
| 267 | return self |
| 268 | |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 269 | class MyClass(metaclass=MyMeta, otherarg=1): |
Nick Coghlan | d78448e | 2016-07-30 16:26:03 +1000 | [diff] [blame] | 270 | pass |
| 271 | |
| 272 | self.assertEqual(MyClass.otherarg, 1) |
| 273 | |
| 274 | def test_type(self): |
| 275 | t = type('NewClass', (object,), {}) |
| 276 | self.assertIsInstance(t, type) |
| 277 | self.assertEqual(t.__name__, 'NewClass') |
| 278 | |
| 279 | with self.assertRaises(TypeError): |
| 280 | type(name='NewClass', bases=(object,), dict={}) |
| 281 | |
| 282 | |
| 283 | if __name__ == "__main__": |
Berker Peksag | 01d1719 | 2016-07-30 14:06:15 +0300 | [diff] [blame] | 284 | unittest.main() |