54 lines
1.5 KiB
Python
54 lines
1.5 KiB
Python
"""Test module for `archey.singleton`"""
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import unittest
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from abc import ABCMeta
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from archey.singleton import Singleton
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class _SimpleCounter(metaclass=Singleton):
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def __init__(self):
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self._counter = 0
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self.an_object = {}
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def increment(self):
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"""Adds `1` to the internal counter"""
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self._counter += 1
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def get(self):
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"""Returns the internal counter value"""
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return self._counter
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class TestSingleton(unittest.TestCase):
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"""Test cases for our `Singleton` meta-class"""
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def test_singleton_itself(self):
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"""Verifies `Singleton` hierarchy"""
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self.assertTrue(issubclass(Singleton, type))
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self.assertTrue(issubclass(Singleton, ABCMeta))
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self.assertTrue(isinstance(_SimpleCounter, Singleton))
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def test_singleton_subclass_instances(self):
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"""Simple tests for `Singleton` sub-class instantiation results"""
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counter_1 = _SimpleCounter()
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counter_2 = _SimpleCounter()
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self.assertIs(counter_1, counter_2)
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self.assertEqual(counter_1, counter_2)
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# Modifies `counter_1`'s internal value.
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counter_1.increment()
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# These values should be equals.
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self.assertEqual(counter_1.get(), counter_2.get())
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# Internal objects are also the same.
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self.assertIs(counter_1.an_object, counter_2.an_object)
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def test_singleton_instantiations(self):
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"""Simple test for `Singleton` (direct) instantiation"""
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self.assertRaises(TypeError, Singleton)
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if __name__ == "__main__":
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unittest.main()
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