Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 1 | """Unit tests for __instancecheck__ and __subclasscheck__.""" |
| 2 | |
| 3 | import unittest |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 4 | |
| 5 | |
| 6 | class ABC(type): |
| 7 | |
| 8 | def __instancecheck__(cls, inst): |
| 9 | """Implement isinstance(inst, cls).""" |
| 10 | return any(cls.__subclasscheck__(c) |
| 11 | for c in {type(inst), inst.__class__}) |
| 12 | |
| 13 | def __subclasscheck__(cls, sub): |
| 14 | """Implement issubclass(sub, cls).""" |
| 15 | candidates = cls.__dict__.get("__subclass__", set()) | {cls} |
| 16 | return any(c in candidates for c in sub.mro()) |
| 17 | |
| 18 | |
| 19 | class Integer(metaclass=ABC): |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 20 | __subclass__ = {int} |
| 21 | |
| 22 | |
| 23 | class SubInt(Integer): |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 24 | pass |
| 25 | |
| 26 | |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 27 | class TypeChecksTest(unittest.TestCase): |
| 28 | |
| 29 | def testIsSubclassInternal(self): |
| 30 | self.assertEqual(Integer.__subclasscheck__(int), True) |
| 31 | self.assertEqual(Integer.__subclasscheck__(float), False) |
| 32 | |
| 33 | def testIsSubclassBuiltin(self): |
| 34 | self.assertEqual(issubclass(int, Integer), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 35 | self.assertEqual(issubclass(int, (Integer,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 36 | self.assertEqual(issubclass(float, Integer), False) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 37 | self.assertEqual(issubclass(float, (Integer,)), False) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 38 | |
| 39 | def testIsInstanceBuiltin(self): |
| 40 | self.assertEqual(isinstance(42, Integer), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 41 | self.assertEqual(isinstance(42, (Integer,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 42 | self.assertEqual(isinstance(3.14, Integer), False) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 43 | self.assertEqual(isinstance(3.14, (Integer,)), False) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 44 | |
| 45 | def testIsInstanceActual(self): |
| 46 | self.assertEqual(isinstance(Integer(), Integer), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 47 | self.assertEqual(isinstance(Integer(), (Integer,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 48 | |
| 49 | def testIsSubclassActual(self): |
| 50 | self.assertEqual(issubclass(Integer, Integer), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 51 | self.assertEqual(issubclass(Integer, (Integer,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 52 | |
| 53 | def testSubclassBehavior(self): |
| 54 | self.assertEqual(issubclass(SubInt, Integer), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 55 | self.assertEqual(issubclass(SubInt, (Integer,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 56 | self.assertEqual(issubclass(SubInt, SubInt), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 57 | self.assertEqual(issubclass(SubInt, (SubInt,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 58 | self.assertEqual(issubclass(Integer, SubInt), False) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 59 | self.assertEqual(issubclass(Integer, (SubInt,)), False) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 60 | self.assertEqual(issubclass(int, SubInt), False) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 61 | self.assertEqual(issubclass(int, (SubInt,)), False) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 62 | self.assertEqual(isinstance(SubInt(), Integer), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 63 | self.assertEqual(isinstance(SubInt(), (Integer,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 64 | self.assertEqual(isinstance(SubInt(), SubInt), True) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 65 | self.assertEqual(isinstance(SubInt(), (SubInt,)), True) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 66 | self.assertEqual(isinstance(42, SubInt), False) |
Antoine Pitrou | ec569b7 | 2008-08-26 22:40:48 +0000 | [diff] [blame] | 67 | self.assertEqual(isinstance(42, (SubInt,)), False) |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 68 | |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 69 | |
Guido van Rossum | adee45e | 2007-05-25 17:55:52 +0000 | [diff] [blame] | 70 | if __name__ == "__main__": |
| 71 | unittest.main() |