Python code coverage for Lib/test/test_subclassinit.py

#	count	content
1	n/a	import types
2	n/a	import unittest
3	n/a
4	n/a
5	n/a	class Test(unittest.TestCase):
6	n/a	def test_init_subclass(self):
7	n/a	class A:
8	n/a	initialized = False
9	n/a
10	n/a	def __init_subclass__(cls):
11	n/a	super().__init_subclass__()
12	n/a	cls.initialized = True
13	n/a
14	n/a	class B(A):
15	n/a	pass
16	n/a
17	n/a	self.assertFalse(A.initialized)
18	n/a	self.assertTrue(B.initialized)
19	n/a
20	n/a	def test_init_subclass_dict(self):
21	n/a	class A(dict):
22	n/a	initialized = False
23	n/a
24	n/a	def __init_subclass__(cls):
25	n/a	super().__init_subclass__()
26	n/a	cls.initialized = True
27	n/a
28	n/a	class B(A):
29	n/a	pass
30	n/a
31	n/a	self.assertFalse(A.initialized)
32	n/a	self.assertTrue(B.initialized)
33	n/a
34	n/a	def test_init_subclass_kwargs(self):
35	n/a	class A:
36	n/a	def __init_subclass__(cls, **kwargs):
37	n/a	cls.kwargs = kwargs
38	n/a
39	n/a	class B(A, x=3):
40	n/a	pass
41	n/a
42	n/a	self.assertEqual(B.kwargs, dict(x=3))
43	n/a
44	n/a	def test_init_subclass_error(self):
45	n/a	class A:
46	n/a	def __init_subclass__(cls):
47	n/a	raise RuntimeError
48	n/a
49	n/a	with self.assertRaises(RuntimeError):
50	n/a	class B(A):
51	n/a	pass
52	n/a
53	n/a	def test_init_subclass_wrong(self):
54	n/a	class A:
55	n/a	def __init_subclass__(cls, whatever):
56	n/a	pass
57	n/a
58	n/a	with self.assertRaises(TypeError):
59	n/a	class B(A):
60	n/a	pass
61	n/a
62	n/a	def test_init_subclass_skipped(self):
63	n/a	class BaseWithInit:
64	n/a	def __init_subclass__(cls, **kwargs):
65	n/a	super().__init_subclass__(**kwargs)
66	n/a	cls.initialized = cls
67	n/a
68	n/a	class BaseWithoutInit(BaseWithInit):
69	n/a	pass
70	n/a
71	n/a	class A(BaseWithoutInit):
72	n/a	pass
73	n/a
74	n/a	self.assertIs(A.initialized, A)
75	n/a	self.assertIs(BaseWithoutInit.initialized, BaseWithoutInit)
76	n/a
77	n/a	def test_init_subclass_diamond(self):
78	n/a	class Base:
79	n/a	def __init_subclass__(cls, **kwargs):
80	n/a	super().__init_subclass__(**kwargs)
81	n/a	cls.calls = []
82	n/a
83	n/a	class Left(Base):
84	n/a	pass
85	n/a
86	n/a	class Middle:
87	n/a	def __init_subclass__(cls, middle, **kwargs):
88	n/a	super().__init_subclass__(**kwargs)
89	n/a	cls.calls += [middle]
90	n/a
91	n/a	class Right(Base):
92	n/a	def __init_subclass__(cls, right="right", **kwargs):
93	n/a	super().__init_subclass__(**kwargs)
94	n/a	cls.calls += [right]
95	n/a
96	n/a	class A(Left, Middle, Right, middle="middle"):
97	n/a	pass
98	n/a
99	n/a	self.assertEqual(A.calls, ["right", "middle"])
100	n/a	self.assertEqual(Left.calls, [])
101	n/a	self.assertEqual(Right.calls, [])
102	n/a
103	n/a	def test_set_name(self):
104	n/a	class Descriptor:
105	n/a	def __set_name__(self, owner, name):
106	n/a	self.owner = owner
107	n/a	self.name = name
108	n/a
109	n/a	class A:
110	n/a	d = Descriptor()
111	n/a
112	n/a	self.assertEqual(A.d.name, "d")
113	n/a	self.assertIs(A.d.owner, A)
114	n/a
115	n/a	def test_set_name_metaclass(self):
116	n/a	class Meta(type):
117	n/a	def __new__(cls, name, bases, ns):
118	n/a	ret = super().__new__(cls, name, bases, ns)
119	n/a	self.assertEqual(ret.d.name, "d")
120	n/a	self.assertIs(ret.d.owner, ret)
121	n/a	return 0
122	n/a
123	n/a	class Descriptor:
124	n/a	def __set_name__(self, owner, name):
125	n/a	self.owner = owner
126	n/a	self.name = name
127	n/a
128	n/a	class A(metaclass=Meta):
129	n/a	d = Descriptor()
130	n/a	self.assertEqual(A, 0)
131	n/a
132	n/a	def test_set_name_error(self):
133	n/a	class Descriptor:
134	n/a	def __set_name__(self, owner, name):
135	n/a	1/0
136	n/a
137	n/a	with self.assertRaises(RuntimeError) as cm:
138	n/a	class NotGoingToWork:
139	n/a	attr = Descriptor()
140	n/a
141	n/a	exc = cm.exception
142	n/a	self.assertRegex(str(exc), r'\bNotGoingToWork\b')
143	n/a	self.assertRegex(str(exc), r'\battr\b')
144	n/a	self.assertRegex(str(exc), r'\bDescriptor\b')
145	n/a	self.assertIsInstance(exc.__cause__, ZeroDivisionError)
146	n/a
147	n/a	def test_set_name_wrong(self):
148	n/a	class Descriptor:
149	n/a	def __set_name__(self):
150	n/a	pass
151	n/a
152	n/a	with self.assertRaises(RuntimeError) as cm:
153	n/a	class NotGoingToWork:
154	n/a	attr = Descriptor()
155	n/a
156	n/a	exc = cm.exception
157	n/a	self.assertRegex(str(exc), r'\bNotGoingToWork\b')
158	n/a	self.assertRegex(str(exc), r'\battr\b')
159	n/a	self.assertRegex(str(exc), r'\bDescriptor\b')
160	n/a	self.assertIsInstance(exc.__cause__, TypeError)
161	n/a
162	n/a	def test_set_name_lookup(self):
163	n/a	resolved = []
164	n/a	class NonDescriptor:
165	n/a	def __getattr__(self, name):
166	n/a	resolved.append(name)
167	n/a
168	n/a	class A:
169	n/a	d = NonDescriptor()
170	n/a
171	n/a	self.assertNotIn('__set_name__', resolved,
172	n/a	'__set_name__ is looked up in instance dict')
173	n/a
174	n/a	def test_set_name_init_subclass(self):
175	n/a	class Descriptor:
176	n/a	def __set_name__(self, owner, name):
177	n/a	self.owner = owner
178	n/a	self.name = name
179	n/a
180	n/a	class Meta(type):
181	n/a	def __new__(cls, name, bases, ns):
182	n/a	self = super().__new__(cls, name, bases, ns)
183	n/a	self.meta_owner = self.owner
184	n/a	self.meta_name = self.name
185	n/a	return self
186	n/a
187	n/a	class A:
188	n/a	def __init_subclass__(cls):
189	n/a	cls.owner = cls.d.owner
190	n/a	cls.name = cls.d.name
191	n/a
192	n/a	class B(A, metaclass=Meta):
193	n/a	d = Descriptor()
194	n/a
195	n/a	self.assertIs(B.owner, B)
196	n/a	self.assertEqual(B.name, 'd')
197	n/a	self.assertIs(B.meta_owner, B)
198	n/a	self.assertEqual(B.name, 'd')
199	n/a
200	n/a	def test_set_name_modifying_dict(self):
201	n/a	notified = []
202	n/a	class Descriptor:
203	n/a	def __set_name__(self, owner, name):
204	n/a	setattr(owner, name + 'x', None)
205	n/a	notified.append(name)
206	n/a
207	n/a	class A:
208	n/a	a = Descriptor()
209	n/a	b = Descriptor()
210	n/a	c = Descriptor()
211	n/a	d = Descriptor()
212	n/a	e = Descriptor()
213	n/a
214	n/a	self.assertCountEqual(notified, ['a', 'b', 'c', 'd', 'e'])
215	n/a
216	n/a	def test_errors(self):
217	n/a	class MyMeta(type):
218	n/a	pass
219	n/a
220	n/a	with self.assertRaises(TypeError):
221	n/a	class MyClass(metaclass=MyMeta, otherarg=1):
222	n/a	pass
223	n/a
224	n/a	with self.assertRaises(TypeError):
225	n/a	types.new_class("MyClass", (object,),
226	n/a	dict(metaclass=MyMeta, otherarg=1))
227	n/a	types.prepare_class("MyClass", (object,),
228	n/a	dict(metaclass=MyMeta, otherarg=1))
229	n/a
230	n/a	class MyMeta(type):
231	n/a	def __init__(self, name, bases, namespace, otherarg):
232	n/a	super().__init__(name, bases, namespace)
233	n/a
234	n/a	with self.assertRaises(TypeError):
235	n/a	class MyClass(metaclass=MyMeta, otherarg=1):
236	n/a	pass
237	n/a
238	n/a	class MyMeta(type):
239	n/a	def __new__(cls, name, bases, namespace, otherarg):
240	n/a	return super().__new__(cls, name, bases, namespace)
241	n/a
242	n/a	def __init__(self, name, bases, namespace, otherarg):
243	n/a	super().__init__(name, bases, namespace)
244	n/a	self.otherarg = otherarg
245	n/a
246	n/a	class MyClass(metaclass=MyMeta, otherarg=1):
247	n/a	pass
248	n/a
249	n/a	self.assertEqual(MyClass.otherarg, 1)
250	n/a
251	n/a	def test_errors_changed_pep487(self):
252	n/a	# These tests failed before Python 3.6, PEP 487
253	n/a	class MyMeta(type):
254	n/a	def __new__(cls, name, bases, namespace):
255	n/a	return super().__new__(cls, name=name, bases=bases,
256	n/a	dict=namespace)
257	n/a
258	n/a	with self.assertRaises(TypeError):
259	n/a	class MyClass(metaclass=MyMeta):
260	n/a	pass
261	n/a
262	n/a	class MyMeta(type):
263	n/a	def __new__(cls, name, bases, namespace, otherarg):
264	n/a	self = super().__new__(cls, name, bases, namespace)
265	n/a	self.otherarg = otherarg
266	n/a	return self
267	n/a
268	n/a	class MyClass(metaclass=MyMeta, otherarg=1):
269	n/a	pass
270	n/a
271	n/a	self.assertEqual(MyClass.otherarg, 1)
272	n/a
273	n/a	def test_type(self):
274	n/a	t = type('NewClass', (object,), {})
275	n/a	self.assertIsInstance(t, type)
276	n/a	self.assertEqual(t.__name__, 'NewClass')
277	n/a
278	n/a	with self.assertRaises(TypeError):
279	n/a	type(name='NewClass', bases=(object,), dict={})
280	n/a
281	n/a
282	n/a	if __name__ == "__main__":
283	n/a	unittest.main()