# Copyright 2019 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import unittest
from .composition_parts import Component
from .composition_parts import Identifier
from .make_copy import make_copy
class MakeCopyTest(unittest.TestCase):
def test_primitives(self):
self.assertEqual(None, make_copy(None))
self.assertEqual(True, make_copy(True))
self.assertEqual(False, make_copy(False))
self.assertEqual(42, make_copy(42))
self.assertEqual(3.14, make_copy(3.14))
self.assertEqual('abc', make_copy('abc'))
def test_primitives_subclasses(self):
# Identifier and Component are subclasses of str. Copies of them
# shouldn't change their type.
original = (Identifier('x'), Component('x'))
copy = make_copy(original)
self.assertEqual(original[0], copy[0])
self.assertEqual(original[1], copy[1])
self.assertIsInstance(copy[0], Identifier)
self.assertIsInstance(copy[1], Component)
def test_object_identity(self):
# A diamond structure must be preserved when making a copy.
# /--> B --\
# A --> D
# \--> C --/
# A1->B1, A1->C1, B1->D1, C1->D1 will be copied as;
# A2->B2, A2->C2, B2->D2, C2->D2 where X2 is a copy of X1.
class Obj(object):
pass
class Ref(object):
def __init__(self, value=None):
self.value = value
obj = Obj()
ref1 = Ref(obj)
ref2 = Ref(obj)
self.assertNotEqual(ref1, ref2)
self.assertIs(ref1.value, ref2.value)
copy = make_copy((ref1, ref2))
self.assertIsInstance(copy, tuple)
self.assertIsInstance(copy[0], Ref)
self.assertIsInstance(copy[1], Ref)
self.assertIsNot(copy[0], copy[1])
self.assertIs(copy[0].value, copy[1].value)