1"Test delegator, coverage 100%."
2
3from idlelib.delegator import Delegator
4import unittest
5
6
7class DelegatorTest(unittest.TestCase):
8
9    def test_mydel(self):
10        # Test a simple use scenario.
11
12        # Initialize an int delegator.
13        mydel = Delegator(int)
14        self.assertIs(mydel.delegate, int)
15        self.assertEqual(mydel._Delegator__cache, set())
16        # Trying to access a non-attribute of int fails.
17        self.assertRaises(AttributeError, mydel.__getattr__, 'xyz')
18
19        # Add real int attribute 'bit_length' by accessing it.
20        bl = mydel.bit_length
21        self.assertIs(bl, int.bit_length)
22        self.assertIs(mydel.__dict__['bit_length'], int.bit_length)
23        self.assertEqual(mydel._Delegator__cache, {'bit_length'})
24
25        # Add attribute 'numerator'.
26        mydel.numerator
27        self.assertEqual(mydel._Delegator__cache, {'bit_length', 'numerator'})
28
29        # Delete 'numerator'.
30        del mydel.numerator
31        self.assertNotIn('numerator', mydel.__dict__)
32        # The current implementation leaves  it in the name cache.
33        # self.assertIn('numerator', mydel._Delegator__cache)
34        # However, this is not required and not part of the specification
35
36        # Change delegate to float, first resetting the attributes.
37        mydel.setdelegate(float)  # calls resetcache
38        self.assertNotIn('bit_length', mydel.__dict__)
39        self.assertEqual(mydel._Delegator__cache, set())
40        self.assertIs(mydel.delegate, float)
41
42
43if __name__ == '__main__':
44    unittest.main(verbosity=2, exit=2)
45