Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 1 | """Unit tests for zero-argument super() & related machinery.""" |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 2 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 3 | import unittest |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 4 | |
| 5 | |
| 6 | class A: |
| 7 | def f(self): |
| 8 | return 'A' |
| 9 | @classmethod |
| 10 | def cm(cls): |
| 11 | return (cls, 'A') |
| 12 | |
| 13 | class B(A): |
| 14 | def f(self): |
| 15 | return super().f() + 'B' |
| 16 | @classmethod |
| 17 | def cm(cls): |
| 18 | return (cls, super().cm(), 'B') |
| 19 | |
| 20 | class C(A): |
| 21 | def f(self): |
| 22 | return super().f() + 'C' |
| 23 | @classmethod |
| 24 | def cm(cls): |
| 25 | return (cls, super().cm(), 'C') |
| 26 | |
| 27 | class D(C, B): |
| 28 | def f(self): |
| 29 | return super().f() + 'D' |
| 30 | def cm(cls): |
| 31 | return (cls, super().cm(), 'D') |
| 32 | |
| 33 | class E(D): |
| 34 | pass |
| 35 | |
| 36 | class F(E): |
| 37 | f = E.f |
| 38 | |
| 39 | class G(A): |
| 40 | pass |
| 41 | |
| 42 | |
| 43 | class TestSuper(unittest.TestCase): |
| 44 | |
Benjamin Peterson | a29ac45 | 2013-05-17 11:33:26 -0500 | [diff] [blame] | 45 | def tearDown(self): |
| 46 | # This fixes the damage that test_various___class___pathologies does. |
| 47 | nonlocal __class__ |
| 48 | __class__ = TestSuper |
| 49 | |
Benjamin Peterson | 206cd1c | 2011-06-19 17:49:13 -0500 | [diff] [blame] | 50 | def test_basics_working(self): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 51 | self.assertEqual(D().f(), 'ABCD') |
| 52 | |
Benjamin Peterson | 206cd1c | 2011-06-19 17:49:13 -0500 | [diff] [blame] | 53 | def test_class_getattr_working(self): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 54 | self.assertEqual(D.f(D()), 'ABCD') |
| 55 | |
Benjamin Peterson | 206cd1c | 2011-06-19 17:49:13 -0500 | [diff] [blame] | 56 | def test_subclass_no_override_working(self): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 57 | self.assertEqual(E().f(), 'ABCD') |
| 58 | self.assertEqual(E.f(E()), 'ABCD') |
| 59 | |
Benjamin Peterson | 206cd1c | 2011-06-19 17:49:13 -0500 | [diff] [blame] | 60 | def test_unbound_method_transfer_working(self): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 61 | self.assertEqual(F().f(), 'ABCD') |
| 62 | self.assertEqual(F.f(F()), 'ABCD') |
| 63 | |
Benjamin Peterson | 206cd1c | 2011-06-19 17:49:13 -0500 | [diff] [blame] | 64 | def test_class_methods_still_working(self): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 65 | self.assertEqual(A.cm(), (A, 'A')) |
| 66 | self.assertEqual(A().cm(), (A, 'A')) |
| 67 | self.assertEqual(G.cm(), (G, 'A')) |
| 68 | self.assertEqual(G().cm(), (G, 'A')) |
| 69 | |
Benjamin Peterson | 206cd1c | 2011-06-19 17:49:13 -0500 | [diff] [blame] | 70 | def test_super_in_class_methods_working(self): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 71 | d = D() |
| 72 | self.assertEqual(d.cm(), (d, (D, (D, (D, 'A'), 'B'), 'C'), 'D')) |
| 73 | e = E() |
| 74 | self.assertEqual(e.cm(), (e, (E, (E, (E, 'A'), 'B'), 'C'), 'D')) |
| 75 | |
Benjamin Peterson | 206cd1c | 2011-06-19 17:49:13 -0500 | [diff] [blame] | 76 | def test_super_with_closure(self): |
Barry Warsaw | 91cc8fb | 2008-11-20 20:01:57 +0000 | [diff] [blame] | 77 | # Issue4360: super() did not work in a function that |
| 78 | # contains a closure |
| 79 | class E(A): |
| 80 | def f(self): |
| 81 | def nested(): |
| 82 | self |
| 83 | return super().f() + 'E' |
| 84 | |
| 85 | self.assertEqual(E().f(), 'AE') |
| 86 | |
Benjamin Peterson | 312595c | 2013-05-15 15:26:42 -0500 | [diff] [blame] | 87 | def test_various___class___pathologies(self): |
Benjamin Peterson | f5ff223 | 2011-06-19 19:42:22 -0500 | [diff] [blame] | 88 | # See issue #12370 |
| 89 | class X(A): |
| 90 | def f(self): |
| 91 | return super().f() |
| 92 | __class__ = 413 |
| 93 | x = X() |
| 94 | self.assertEqual(x.f(), 'A') |
| 95 | self.assertEqual(x.__class__, 413) |
Benjamin Peterson | 312595c | 2013-05-15 15:26:42 -0500 | [diff] [blame] | 96 | class X: |
| 97 | x = __class__ |
| 98 | def f(): |
| 99 | __class__ |
| 100 | self.assertIs(X.x, type(self)) |
| 101 | with self.assertRaises(NameError) as e: |
| 102 | exec("""class X: |
| 103 | __class__ |
| 104 | def f(): |
| 105 | __class__""", globals(), {}) |
| 106 | self.assertIs(type(e.exception), NameError) # Not UnboundLocalError |
| 107 | class X: |
| 108 | global __class__ |
| 109 | __class__ = 42 |
| 110 | def f(): |
| 111 | __class__ |
| 112 | self.assertEqual(globals()["__class__"], 42) |
| 113 | del globals()["__class__"] |
| 114 | self.assertNotIn("__class__", X.__dict__) |
| 115 | class X: |
| 116 | nonlocal __class__ |
| 117 | __class__ = 42 |
| 118 | def f(): |
| 119 | __class__ |
| 120 | self.assertEqual(__class__, 42) |
Benjamin Peterson | f5ff223 | 2011-06-19 19:42:22 -0500 | [diff] [blame] | 121 | |
Nick Coghlan | 0b43bcf | 2012-05-27 18:17:07 +1000 | [diff] [blame] | 122 | def test___class___instancemethod(self): |
| 123 | # See issue #14857 |
| 124 | class X: |
| 125 | def f(self): |
| 126 | return __class__ |
| 127 | self.assertIs(X().f(), X) |
| 128 | |
| 129 | def test___class___classmethod(self): |
| 130 | # See issue #14857 |
| 131 | class X: |
| 132 | @classmethod |
| 133 | def f(cls): |
| 134 | return __class__ |
| 135 | self.assertIs(X.f(), X) |
| 136 | |
| 137 | def test___class___staticmethod(self): |
| 138 | # See issue #14857 |
| 139 | class X: |
| 140 | @staticmethod |
| 141 | def f(): |
| 142 | return __class__ |
| 143 | self.assertIs(X.f(), X) |
| 144 | |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 145 | def test___class___new(self): |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 146 | # See issue #23722 |
| 147 | # Ensure zero-arg super() works as soon as type.__new__() is completed |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 148 | test_class = None |
| 149 | |
| 150 | class Meta(type): |
| 151 | def __new__(cls, name, bases, namespace): |
| 152 | nonlocal test_class |
| 153 | self = super().__new__(cls, name, bases, namespace) |
| 154 | test_class = self.f() |
| 155 | return self |
| 156 | |
| 157 | class A(metaclass=Meta): |
| 158 | @staticmethod |
| 159 | def f(): |
| 160 | return __class__ |
| 161 | |
| 162 | self.assertIs(test_class, A) |
| 163 | |
| 164 | def test___class___delayed(self): |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 165 | # See issue #23722 |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 166 | test_namespace = None |
| 167 | |
| 168 | class Meta(type): |
| 169 | def __new__(cls, name, bases, namespace): |
| 170 | nonlocal test_namespace |
| 171 | test_namespace = namespace |
| 172 | return None |
| 173 | |
Serhiy Storchaka | f5e7b19 | 2018-05-20 08:48:12 +0300 | [diff] [blame] | 174 | class A(metaclass=Meta): |
| 175 | @staticmethod |
| 176 | def f(): |
| 177 | return __class__ |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 178 | |
| 179 | self.assertIs(A, None) |
| 180 | |
| 181 | B = type("B", (), test_namespace) |
| 182 | self.assertIs(B.f(), B) |
| 183 | |
| 184 | def test___class___mro(self): |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 185 | # See issue #23722 |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 186 | test_class = None |
| 187 | |
| 188 | class Meta(type): |
| 189 | def mro(self): |
| 190 | # self.f() doesn't work yet... |
| 191 | self.__dict__["f"]() |
| 192 | return super().mro() |
| 193 | |
| 194 | class A(metaclass=Meta): |
| 195 | def f(): |
| 196 | nonlocal test_class |
| 197 | test_class = __class__ |
| 198 | |
| 199 | self.assertIs(test_class, A) |
| 200 | |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 201 | def test___classcell___expected_behaviour(self): |
| 202 | # See issue #23722 |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 203 | class Meta(type): |
| 204 | def __new__(cls, name, bases, namespace): |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 205 | nonlocal namespace_snapshot |
| 206 | namespace_snapshot = namespace.copy() |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 207 | return super().__new__(cls, name, bases, namespace) |
| 208 | |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 209 | # __classcell__ is injected into the class namespace by the compiler |
| 210 | # when at least one method needs it, and should be omitted otherwise |
| 211 | namespace_snapshot = None |
| 212 | class WithoutClassRef(metaclass=Meta): |
| 213 | pass |
| 214 | self.assertNotIn("__classcell__", namespace_snapshot) |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 215 | |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 216 | # With zero-arg super() or an explicit __class__ reference, |
| 217 | # __classcell__ is the exact cell reference to be populated by |
| 218 | # type.__new__ |
| 219 | namespace_snapshot = None |
| 220 | class WithClassRef(metaclass=Meta): |
| 221 | def f(self): |
| 222 | return __class__ |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 223 | |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 224 | class_cell = namespace_snapshot["__classcell__"] |
| 225 | method_closure = WithClassRef.f.__closure__ |
| 226 | self.assertEqual(len(method_closure), 1) |
| 227 | self.assertIs(class_cell, method_closure[0]) |
| 228 | # Ensure the cell reference *doesn't* get turned into an attribute |
| 229 | with self.assertRaises(AttributeError): |
| 230 | WithClassRef.__classcell__ |
| 231 | |
| 232 | def test___classcell___missing(self): |
| 233 | # See issue #23722 |
| 234 | # Some metaclasses may not pass the original namespace to type.__new__ |
| 235 | # We test that case here by forcibly deleting __classcell__ |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 236 | class Meta(type): |
| 237 | def __new__(cls, name, bases, namespace): |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 238 | namespace.pop('__classcell__', None) |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 239 | return super().__new__(cls, name, bases, namespace) |
| 240 | |
Serhiy Storchaka | f5e7b19 | 2018-05-20 08:48:12 +0300 | [diff] [blame] | 241 | # The default case should continue to work without any errors |
| 242 | class WithoutClassRef(metaclass=Meta): |
| 243 | pass |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 244 | |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 245 | # With zero-arg super() or an explicit __class__ reference, we expect |
Serhiy Storchaka | f5e7b19 | 2018-05-20 08:48:12 +0300 | [diff] [blame] | 246 | # __build_class__ to raise a RuntimeError complaining that |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 247 | # __class__ was not set, and asking if __classcell__ was propagated |
| 248 | # to type.__new__. |
Serhiy Storchaka | f5e7b19 | 2018-05-20 08:48:12 +0300 | [diff] [blame] | 249 | expected_error = '__class__ not set.*__classcell__ propagated' |
| 250 | with self.assertRaisesRegex(RuntimeError, expected_error): |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 251 | class WithClassRef(metaclass=Meta): |
| 252 | def f(self): |
| 253 | return __class__ |
Nick Coghlan | 19d2467 | 2016-12-05 16:47:55 +1000 | [diff] [blame] | 254 | |
| 255 | def test___classcell___overwrite(self): |
| 256 | # See issue #23722 |
| 257 | # Overwriting __classcell__ with nonsense is explicitly prohibited |
| 258 | class Meta(type): |
| 259 | def __new__(cls, name, bases, namespace, cell): |
| 260 | namespace['__classcell__'] = cell |
| 261 | return super().__new__(cls, name, bases, namespace) |
| 262 | |
| 263 | for bad_cell in (None, 0, "", object()): |
| 264 | with self.subTest(bad_cell=bad_cell): |
| 265 | with self.assertRaises(TypeError): |
| 266 | class A(metaclass=Meta, cell=bad_cell): |
| 267 | pass |
| 268 | |
| 269 | def test___classcell___wrong_cell(self): |
| 270 | # See issue #23722 |
| 271 | # Pointing the cell reference at the wrong class is also prohibited |
| 272 | class Meta(type): |
| 273 | def __new__(cls, name, bases, namespace): |
| 274 | cls = super().__new__(cls, name, bases, namespace) |
| 275 | B = type("B", (), namespace) |
| 276 | return cls |
| 277 | |
| 278 | with self.assertRaises(TypeError): |
| 279 | class A(metaclass=Meta): |
| 280 | def f(self): |
| 281 | return __class__ |
Nick Coghlan | 944368e | 2016-09-11 14:45:49 +1000 | [diff] [blame] | 282 | |
Benjamin Peterson | 6a42bd6 | 2012-09-01 23:04:38 -0400 | [diff] [blame] | 283 | def test_obscure_super_errors(self): |
| 284 | def f(): |
| 285 | super() |
| 286 | self.assertRaises(RuntimeError, f) |
| 287 | def f(x): |
| 288 | del x |
| 289 | super() |
| 290 | self.assertRaises(RuntimeError, f, None) |
| 291 | class X: |
| 292 | def f(x): |
| 293 | nonlocal __class__ |
| 294 | del __class__ |
| 295 | super() |
| 296 | self.assertRaises(RuntimeError, X().f) |
| 297 | |
Benjamin Peterson | 159ae41 | 2013-05-12 18:16:06 -0500 | [diff] [blame] | 298 | def test_cell_as_self(self): |
| 299 | class X: |
| 300 | def meth(self): |
| 301 | super() |
| 302 | |
| 303 | def f(): |
| 304 | k = X() |
| 305 | def g(): |
| 306 | return k |
| 307 | return g |
| 308 | c = f().__closure__[0] |
| 309 | self.assertRaises(TypeError, X.meth, c) |
| 310 | |
Serhiy Storchaka | 3d74976 | 2016-04-13 15:27:33 +0300 | [diff] [blame] | 311 | def test_super_init_leaks(self): |
| 312 | # Issue #26718: super.__init__ leaked memory if called multiple times. |
| 313 | # This will be caught by regrtest.py -R if this leak. |
| 314 | # NOTE: Despite the use in the test a direct call of super.__init__ |
| 315 | # is not endorsed. |
| 316 | sp = super(float, 1.0) |
| 317 | for i in range(1000): |
| 318 | super.__init__(sp, int, i) |
| 319 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 320 | |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 321 | if __name__ == "__main__": |
| 322 | unittest.main() |