1 | # Copyright 2007 Google, Inc. All Rights Reserved. |
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2 | # Licensed to PSF under a Contributor Agreement. |
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3 | |
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4 | """Unit tests for abc.py.""" |
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5 | |
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6 | import unittest, weakref |
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7 | from test import test_support |
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8 | |
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9 | import abc |
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10 | from inspect import isabstract |
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11 | |
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12 | |
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13 | class TestABC(unittest.TestCase): |
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14 | |
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15 | def test_abstractmethod_basics(self): |
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16 | @abc.abstractmethod |
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17 | def foo(self): pass |
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18 | self.assertTrue(foo.__isabstractmethod__) |
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19 | def bar(self): pass |
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20 | self.assertFalse(hasattr(bar, "__isabstractmethod__")) |
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21 | |
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22 | def test_abstractproperty_basics(self): |
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23 | @abc.abstractproperty |
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24 | def foo(self): pass |
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25 | self.assertTrue(foo.__isabstractmethod__) |
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26 | def bar(self): pass |
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27 | self.assertFalse(hasattr(bar, "__isabstractmethod__")) |
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28 | |
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29 | class C: |
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30 | __metaclass__ = abc.ABCMeta |
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31 | @abc.abstractproperty |
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32 | def foo(self): return 3 |
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33 | class D(C): |
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34 | @property |
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35 | def foo(self): return super(D, self).foo |
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36 | self.assertEqual(D().foo, 3) |
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37 | |
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38 | def test_abstractmethod_integration(self): |
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39 | for abstractthing in [abc.abstractmethod, abc.abstractproperty]: |
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40 | class C: |
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41 | __metaclass__ = abc.ABCMeta |
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42 | @abstractthing |
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43 | def foo(self): pass # abstract |
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44 | def bar(self): pass # concrete |
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45 | self.assertEqual(C.__abstractmethods__, set(["foo"])) |
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46 | self.assertRaises(TypeError, C) # because foo is abstract |
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47 | self.assertTrue(isabstract(C)) |
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48 | class D(C): |
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49 | def bar(self): pass # concrete override of concrete |
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50 | self.assertEqual(D.__abstractmethods__, set(["foo"])) |
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51 | self.assertRaises(TypeError, D) # because foo is still abstract |
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52 | self.assertTrue(isabstract(D)) |
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53 | class E(D): |
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54 | def foo(self): pass |
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55 | self.assertEqual(E.__abstractmethods__, set()) |
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56 | E() # now foo is concrete, too |
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57 | self.assertFalse(isabstract(E)) |
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58 | class F(E): |
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59 | @abstractthing |
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60 | def bar(self): pass # abstract override of concrete |
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61 | self.assertEqual(F.__abstractmethods__, set(["bar"])) |
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62 | self.assertRaises(TypeError, F) # because bar is abstract now |
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63 | self.assertTrue(isabstract(F)) |
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64 | |
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65 | def test_subclass_oldstyle_class(self): |
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66 | class A: |
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67 | __metaclass__ = abc.ABCMeta |
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68 | class OldstyleClass: |
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69 | pass |
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70 | self.assertFalse(issubclass(OldstyleClass, A)) |
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71 | self.assertFalse(issubclass(A, OldstyleClass)) |
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72 | |
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73 | def test_isinstance_class(self): |
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74 | class A: |
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75 | __metaclass__ = abc.ABCMeta |
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76 | class OldstyleClass: |
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77 | pass |
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78 | self.assertFalse(isinstance(OldstyleClass, A)) |
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79 | self.assertTrue(isinstance(OldstyleClass, type(OldstyleClass))) |
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80 | self.assertFalse(isinstance(A, OldstyleClass)) |
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81 | # This raises a recursion depth error, but is low-priority: |
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82 | # self.assertTrue(isinstance(A, abc.ABCMeta)) |
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83 | |
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84 | def test_registration_basics(self): |
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85 | class A: |
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86 | __metaclass__ = abc.ABCMeta |
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87 | class B(object): |
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88 | pass |
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89 | b = B() |
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90 | self.assertFalse(issubclass(B, A)) |
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91 | self.assertFalse(issubclass(B, (A,))) |
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92 | self.assertNotIsInstance(b, A) |
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93 | self.assertNotIsInstance(b, (A,)) |
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94 | A.register(B) |
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95 | self.assertTrue(issubclass(B, A)) |
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96 | self.assertTrue(issubclass(B, (A,))) |
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97 | self.assertIsInstance(b, A) |
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98 | self.assertIsInstance(b, (A,)) |
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99 | class C(B): |
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100 | pass |
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101 | c = C() |
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102 | self.assertTrue(issubclass(C, A)) |
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103 | self.assertTrue(issubclass(C, (A,))) |
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104 | self.assertIsInstance(c, A) |
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105 | self.assertIsInstance(c, (A,)) |
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106 | |
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107 | def test_isinstance_invalidation(self): |
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108 | class A: |
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109 | __metaclass__ = abc.ABCMeta |
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110 | class B(object): |
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111 | pass |
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112 | b = B() |
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113 | self.assertFalse(isinstance(b, A)) |
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114 | self.assertFalse(isinstance(b, (A,))) |
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115 | A.register(B) |
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116 | self.assertTrue(isinstance(b, A)) |
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117 | self.assertTrue(isinstance(b, (A,))) |
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118 | |
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119 | def test_registration_builtins(self): |
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120 | class A: |
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121 | __metaclass__ = abc.ABCMeta |
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122 | A.register(int) |
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123 | self.assertIsInstance(42, A) |
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124 | self.assertIsInstance(42, (A,)) |
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125 | self.assertTrue(issubclass(int, A)) |
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126 | self.assertTrue(issubclass(int, (A,))) |
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127 | class B(A): |
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128 | pass |
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129 | B.register(basestring) |
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130 | self.assertIsInstance("", A) |
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131 | self.assertIsInstance("", (A,)) |
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132 | self.assertTrue(issubclass(str, A)) |
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133 | self.assertTrue(issubclass(str, (A,))) |
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134 | |
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135 | def test_registration_edge_cases(self): |
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136 | class A: |
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137 | __metaclass__ = abc.ABCMeta |
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138 | A.register(A) # should pass silently |
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139 | class A1(A): |
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140 | pass |
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141 | self.assertRaises(RuntimeError, A1.register, A) # cycles not allowed |
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142 | class B(object): |
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143 | pass |
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144 | A1.register(B) # ok |
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145 | A1.register(B) # should pass silently |
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146 | class C(A): |
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147 | pass |
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148 | A.register(C) # should pass silently |
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149 | self.assertRaises(RuntimeError, C.register, A) # cycles not allowed |
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150 | C.register(B) # ok |
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151 | |
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152 | def test_register_non_class(self): |
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153 | class A(object): |
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154 | __metaclass__ = abc.ABCMeta |
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155 | self.assertRaisesRegexp(TypeError, "Can only register classes", |
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156 | A.register, 4) |
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157 | |
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158 | def test_registration_transitiveness(self): |
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159 | class A: |
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160 | __metaclass__ = abc.ABCMeta |
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161 | self.assertTrue(issubclass(A, A)) |
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162 | self.assertTrue(issubclass(A, (A,))) |
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163 | class B: |
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164 | __metaclass__ = abc.ABCMeta |
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165 | self.assertFalse(issubclass(A, B)) |
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166 | self.assertFalse(issubclass(A, (B,))) |
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167 | self.assertFalse(issubclass(B, A)) |
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168 | self.assertFalse(issubclass(B, (A,))) |
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169 | class C: |
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170 | __metaclass__ = abc.ABCMeta |
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171 | A.register(B) |
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172 | class B1(B): |
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173 | pass |
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174 | self.assertTrue(issubclass(B1, A)) |
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175 | self.assertTrue(issubclass(B1, (A,))) |
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176 | class C1(C): |
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177 | pass |
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178 | B1.register(C1) |
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179 | self.assertFalse(issubclass(C, B)) |
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180 | self.assertFalse(issubclass(C, (B,))) |
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181 | self.assertFalse(issubclass(C, B1)) |
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182 | self.assertFalse(issubclass(C, (B1,))) |
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183 | self.assertTrue(issubclass(C1, A)) |
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184 | self.assertTrue(issubclass(C1, (A,))) |
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185 | self.assertTrue(issubclass(C1, B)) |
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186 | self.assertTrue(issubclass(C1, (B,))) |
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187 | self.assertTrue(issubclass(C1, B1)) |
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188 | self.assertTrue(issubclass(C1, (B1,))) |
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189 | C1.register(int) |
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190 | class MyInt(int): |
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191 | pass |
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192 | self.assertTrue(issubclass(MyInt, A)) |
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193 | self.assertTrue(issubclass(MyInt, (A,))) |
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194 | self.assertIsInstance(42, A) |
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195 | self.assertIsInstance(42, (A,)) |
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196 | |
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197 | def test_all_new_methods_are_called(self): |
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198 | class A: |
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199 | __metaclass__ = abc.ABCMeta |
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200 | class B(object): |
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201 | counter = 0 |
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202 | def __new__(cls): |
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203 | B.counter += 1 |
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204 | return super(B, cls).__new__(cls) |
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205 | class C(A, B): |
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206 | pass |
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207 | self.assertEqual(B.counter, 0) |
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208 | C() |
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209 | self.assertEqual(B.counter, 1) |
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210 | |
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211 | def test_cache_leak(self): |
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212 | # See issue #2521. |
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213 | class A(object): |
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214 | __metaclass__ = abc.ABCMeta |
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215 | @abc.abstractmethod |
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216 | def f(self): |
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217 | pass |
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218 | class C(A): |
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219 | def f(self): |
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220 | A.f(self) |
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221 | r = weakref.ref(C) |
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222 | # Trigger cache. |
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223 | C().f() |
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224 | del C |
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225 | test_support.gc_collect() |
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226 | self.assertEqual(r(), None) |
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227 | |
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228 | def test_main(): |
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229 | test_support.run_unittest(TestABC) |
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230 | |
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231 | |
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232 | if __name__ == "__main__": |
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233 | unittest.main() |
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