summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_funcattrs.py
blob: 5094f7ba1f04dbbc82c4fc5084791f8b7ce27a4c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
from test import support
import types
import unittest


def global_function():
    def inner_function():
        class LocalClass:
            pass
        global inner_global_function
        def inner_global_function():
            def inner_function2():
                pass
            return inner_function2
        return LocalClass
    return lambda: inner_function


class FuncAttrsTest(unittest.TestCase):
    def setUp(self):
        class F:
            def a(self):
                pass
        def b():
            return 3
        self.fi = F()
        self.F = F
        self.b = b

    def cannot_set_attr(self, obj, name, value, exceptions):
        try:
            setattr(obj, name, value)
        except exceptions:
            pass
        else:
            self.fail("shouldn't be able to set %s to %r" % (name, value))
        try:
            delattr(obj, name)
        except exceptions:
            pass
        else:
            self.fail("shouldn't be able to del %s" % name)


class FunctionPropertiesTest(FuncAttrsTest):
    # Include the external setUp method that is common to all tests
    def test_module(self):
        self.assertEqual(self.b.__module__, __name__)

    def test_dir_includes_correct_attrs(self):
        self.b.known_attr = 7
        self.assertIn('known_attr', dir(self.b),
            "set attributes not in dir listing of method")
        # Test on underlying function object of method
        self.F.a.known_attr = 7
        self.assertIn('known_attr', dir(self.fi.a), "set attribute on function "
                     "implementations, should show up in next dir")

    def test_duplicate_function_equality(self):
        # Body of `duplicate' is the exact same as self.b
        def duplicate():
            'my docstring'
            return 3
        self.assertNotEqual(self.b, duplicate)

    def test_copying___code__(self):
        def test(): pass
        self.assertEqual(test(), None)
        test.__code__ = self.b.__code__
        self.assertEqual(test(), 3) # self.b always returns 3, arbitrarily

    def test___globals__(self):
        self.assertIs(self.b.__globals__, globals())
        self.cannot_set_attr(self.b, '__globals__', 2,
                             (AttributeError, TypeError))

    def test___closure__(self):
        a = 12
        def f(): print(a)
        c = f.__closure__
        self.assertIsInstance(c, tuple)
        self.assertEqual(len(c), 1)
        # don't have a type object handy
        self.assertEqual(c[0].__class__.__name__, "cell")
        self.cannot_set_attr(f, "__closure__", c, AttributeError)

    def test_empty_cell(self):
        def f(): print(a)
        try:
            f.__closure__[0].cell_contents
        except ValueError:
            pass
        else:
            self.fail("shouldn't be able to read an empty cell")
        a = 12

    def test___name__(self):
        self.assertEqual(self.b.__name__, 'b')
        self.b.__name__ = 'c'
        self.assertEqual(self.b.__name__, 'c')
        self.b.__name__ = 'd'
        self.assertEqual(self.b.__name__, 'd')
        # __name__ and __name__ must be a string
        self.cannot_set_attr(self.b, '__name__', 7, TypeError)
        # __name__ must be available when in restricted mode. Exec will raise
        # AttributeError if __name__ is not available on f.
        s = """def f(): pass\nf.__name__"""
        exec(s, {'__builtins__': {}})
        # Test on methods, too
        self.assertEqual(self.fi.a.__name__, 'a')
        self.cannot_set_attr(self.fi.a, "__name__", 'a', AttributeError)

    def test___qualname__(self):
        # PEP 3155
        self.assertEqual(self.b.__qualname__, 'FuncAttrsTest.setUp.<locals>.b')
        self.assertEqual(FuncAttrsTest.setUp.__qualname__, 'FuncAttrsTest.setUp')
        self.assertEqual(global_function.__qualname__, 'global_function')
        self.assertEqual(global_function().__qualname__,
                         'global_function.<locals>.<lambda>')
        self.assertEqual(global_function()().__qualname__,
                         'global_function.<locals>.inner_function')
        self.assertEqual(global_function()()().__qualname__,
                         'global_function.<locals>.inner_function.<locals>.LocalClass')
        self.assertEqual(inner_global_function.__qualname__, 'inner_global_function')
        self.assertEqual(inner_global_function().__qualname__, 'inner_global_function.<locals>.inner_function2')
        self.b.__qualname__ = 'c'
        self.assertEqual(self.b.__qualname__, 'c')
        self.b.__qualname__ = 'd'
        self.assertEqual(self.b.__qualname__, 'd')
        # __qualname__ must be a string
        self.cannot_set_attr(self.b, '__qualname__', 7, TypeError)

    def test___code__(self):
        num_one, num_two = 7, 8
        def a(): pass
        def b(): return 12
        def c(): return num_one
        def d(): return num_two
        def e(): return num_one, num_two
        for func in [a, b, c, d, e]:
            self.assertEqual(type(func.__code__), types.CodeType)
        self.assertEqual(c(), 7)
        self.assertEqual(d(), 8)
        d.__code__ = c.__code__
        self.assertEqual(c.__code__, d.__code__)
        self.assertEqual(c(), 7)
        # self.assertEqual(d(), 7)
        try:
            b.__code__ = c.__code__
        except ValueError:
            pass
        else:
            self.fail("__code__ with different numbers of free vars should "
                      "not be possible")
        try:
            e.__code__ = d.__code__
        except ValueError:
            pass
        else:
            self.fail("__code__ with different numbers of free vars should "
                      "not be possible")

    def test_blank_func_defaults(self):
        self.assertEqual(self.b.__defaults__, None)
        del self.b.__defaults__
        self.assertEqual(self.b.__defaults__, None)

    def test_func_default_args(self):
        def first_func(a, b):
            return a+b
        def second_func(a=1, b=2):
            return a+b
        self.assertEqual(first_func.__defaults__, None)
        self.assertEqual(second_func.__defaults__, (1, 2))
        first_func.__defaults__ = (1, 2)
        self.assertEqual(first_func.__defaults__, (1, 2))
        self.assertEqual(first_func(), 3)
        self.assertEqual(first_func(3), 5)
        self.assertEqual(first_func(3, 5), 8)
        del second_func.__defaults__
        self.assertEqual(second_func.__defaults__, None)
        try:
            second_func()
        except TypeError:
            pass
        else:
            self.fail("__defaults__ does not update; deleting it does not "
                      "remove requirement")


class InstancemethodAttrTest(FuncAttrsTest):

    def test___class__(self):
        self.assertEqual(self.fi.a.__self__.__class__, self.F)
        self.cannot_set_attr(self.fi.a, "__class__", self.F, TypeError)

    def test___func__(self):
        self.assertEqual(self.fi.a.__func__, self.F.a)
        self.cannot_set_attr(self.fi.a, "__func__", self.F.a, AttributeError)

    def test___self__(self):
        self.assertEqual(self.fi.a.__self__, self.fi)
        self.cannot_set_attr(self.fi.a, "__self__", self.fi, AttributeError)

    def test___func___non_method(self):
        # Behavior should be the same when a method is added via an attr
        # assignment
        self.fi.id = types.MethodType(id, self.fi)
        self.assertEqual(self.fi.id(), id(self.fi))
        # Test usage
        try:
            self.fi.id.unknown_attr
        except AttributeError:
            pass
        else:
            self.fail("using unknown attributes should raise AttributeError")
        # Test assignment and deletion
        self.cannot_set_attr(self.fi.id, 'unknown_attr', 2, AttributeError)


class ArbitraryFunctionAttrTest(FuncAttrsTest):
    def test_set_attr(self):
        self.b.known_attr = 7
        self.assertEqual(self.b.known_attr, 7)
        try:
            self.fi.a.known_attr = 7
        except AttributeError:
            pass
        else:
            self.fail("setting attributes on methods should raise error")

    def test_delete_unknown_attr(self):
        try:
            del self.b.unknown_attr
        except AttributeError:
            pass
        else:
            self.fail("deleting unknown attribute should raise TypeError")

    def test_unset_attr(self):
        for func in [self.b, self.fi.a]:
            try:
                func.non_existent_attr
            except AttributeError:
                pass
            else:
                self.fail("using unknown attributes should raise "
                          "AttributeError")


class FunctionDictsTest(FuncAttrsTest):
    def test_setting_dict_to_invalid(self):
        self.cannot_set_attr(self.b, '__dict__', None, TypeError)
        from collections import UserDict
        d = UserDict({'known_attr': 7})
        self.cannot_set_attr(self.fi.a.__func__, '__dict__', d, TypeError)

    def test_setting_dict_to_valid(self):
        d = {'known_attr': 7}
        self.b.__dict__ = d
        # Test assignment
        self.assertIs(d, self.b.__dict__)
        # ... and on all the different ways of referencing the method's func
        self.F.a.__dict__ = d
        self.assertIs(d, self.fi.a.__func__.__dict__)
        self.assertIs(d, self.fi.a.__dict__)
        # Test value
        self.assertEqual(self.b.known_attr, 7)
        self.assertEqual(self.b.__dict__['known_attr'], 7)
        # ... and again, on all the different method's names
        self.assertEqual(self.fi.a.__func__.known_attr, 7)
        self.assertEqual(self.fi.a.known_attr, 7)

    def test_delete___dict__(self):
        try:
            del self.b.__dict__
        except TypeError:
            pass
        else:
            self.fail("deleting function dictionary should raise TypeError")

    def test_unassigned_dict(self):
        self.assertEqual(self.b.__dict__, {})

    def test_func_as_dict_key(self):
        value = "Some string"
        d = {}
        d[self.b] = value
        self.assertEqual(d[self.b], value)


class FunctionDocstringTest(FuncAttrsTest):
    def test_set_docstring_attr(self):
        self.assertEqual(self.b.__doc__, None)
        docstr = "A test method that does nothing"
        self.b.__doc__ = docstr
        self.F.a.__doc__ = docstr
        self.assertEqual(self.b.__doc__, docstr)
        self.assertEqual(self.fi.a.__doc__, docstr)
        self.cannot_set_attr(self.fi.a, "__doc__", docstr, AttributeError)

    def test_delete_docstring(self):
        self.b.__doc__ = "The docstring"
        del self.b.__doc__
        self.assertEqual(self.b.__doc__, None)


def cell(value):
    """Create a cell containing the given value."""
    def f():
        print(a)
    a = value
    return f.__closure__[0]

def empty_cell(empty=True):
    """Create an empty cell."""
    def f():
        print(a)
    # the intent of the following line is simply "if False:";  it's
    # spelt this way to avoid the danger that a future optimization
    # might simply remove an "if False:" code block.
    if not empty:
        a = 1729
    return f.__closure__[0]


class CellTest(unittest.TestCase):
    def test_comparison(self):
        # These tests are here simply to exercise the comparison code;
        # their presence should not be interpreted as providing any
        # guarantees about the semantics (or even existence) of cell
        # comparisons in future versions of CPython.
        self.assertTrue(cell(2) < cell(3))
        self.assertTrue(empty_cell() < cell('saturday'))
        self.assertTrue(empty_cell() == empty_cell())
        self.assertTrue(cell(-36) == cell(-36.0))
        self.assertTrue(cell(True) > empty_cell())


class StaticMethodAttrsTest(unittest.TestCase):
    def test_func_attribute(self):
        def f():
            pass

        c = classmethod(f)
        self.assertTrue(c.__func__ is f)

        s = staticmethod(f)
        self.assertTrue(s.__func__ is f)


class BuiltinFunctionPropertiesTest(unittest.TestCase):
    # XXX Not sure where this should really go since I can't find a
    # test module specifically for builtin_function_or_method.

    def test_builtin__qualname__(self):
        import time

        # builtin function:
        self.assertEqual(len.__qualname__, 'len')
        self.assertEqual(time.time.__qualname__, 'time')

        # builtin classmethod:
        self.assertEqual(dict.fromkeys.__qualname__, 'dict.fromkeys')
        self.assertEqual(float.__getformat__.__qualname__,
                         'float.__getformat__')

        # builtin staticmethod:
        self.assertEqual(str.maketrans.__qualname__, 'str.maketrans')
        self.assertEqual(bytes.maketrans.__qualname__, 'bytes.maketrans')

        # builtin bound instance method:
        self.assertEqual([1, 2, 3].append.__qualname__, 'list.append')
        self.assertEqual({'foo': 'bar'}.pop.__qualname__, 'dict.pop')


def test_main():
    support.run_unittest(FunctionPropertiesTest, InstancemethodAttrTest,
                              ArbitraryFunctionAttrTest, FunctionDictsTest,
                              FunctionDocstringTest, CellTest,
                              StaticMethodAttrsTest,
                              BuiltinFunctionPropertiesTest)

if __name__ == "__main__":
    test_main()