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1import unittest
2from weakref import WeakSet
3import string
4from collections import UserString as ustr
5import gc
6import contextlib
7
8
9class Foo:
10    pass
11
12class RefCycle:
13    def __init__(self):
14        self.cycle = self
15
16
17class TestWeakSet(unittest.TestCase):
18
19    def setUp(self):
20        # need to keep references to them
21        self.items = [ustr(c) for c in ('a', 'b', 'c')]
22        self.items2 = [ustr(c) for c in ('x', 'y', 'z')]
23        self.ab_items = [ustr(c) for c in 'ab']
24        self.abcde_items = [ustr(c) for c in 'abcde']
25        self.def_items = [ustr(c) for c in 'def']
26        self.ab_weakset = WeakSet(self.ab_items)
27        self.abcde_weakset = WeakSet(self.abcde_items)
28        self.def_weakset = WeakSet(self.def_items)
29        self.letters = [ustr(c) for c in string.ascii_letters]
30        self.s = WeakSet(self.items)
31        self.d = dict.fromkeys(self.items)
32        self.obj = ustr('F')
33        self.fs = WeakSet([self.obj])
34
35    def test_methods(self):
36        weaksetmethods = dir(WeakSet)
37        for method in dir(set):
38            if method == 'test_c_api' or method.startswith('_'):
39                continue
40            self.assertIn(method, weaksetmethods,
41                         "WeakSet missing method " + method)
42
43    def test_new_or_init(self):
44        self.assertRaises(TypeError, WeakSet, [], 2)
45
46    def test_len(self):
47        self.assertEqual(len(self.s), len(self.d))
48        self.assertEqual(len(self.fs), 1)
49        del self.obj
50        self.assertEqual(len(self.fs), 0)
51
52    def test_contains(self):
53        for c in self.letters:
54            self.assertEqual(c in self.s, c in self.d)
55        # 1 is not weakref'able, but that TypeError is caught by __contains__
56        self.assertNotIn(1, self.s)
57        self.assertIn(self.obj, self.fs)
58        del self.obj
59        self.assertNotIn(ustr('F'), self.fs)
60
61    def test_union(self):
62        u = self.s.union(self.items2)
63        for c in self.letters:
64            self.assertEqual(c in u, c in self.d or c in self.items2)
65        self.assertEqual(self.s, WeakSet(self.items))
66        self.assertEqual(type(u), WeakSet)
67        self.assertRaises(TypeError, self.s.union, [[]])
68        for C in set, frozenset, dict.fromkeys, list, tuple:
69            x = WeakSet(self.items + self.items2)
70            c = C(self.items2)
71            self.assertEqual(self.s.union(c), x)
72            del c
73        self.assertEqual(len(u), len(self.items) + len(self.items2))
74        self.items2.pop()
75        gc.collect()
76        self.assertEqual(len(u), len(self.items) + len(self.items2))
77
78    def test_or(self):
79        i = self.s.union(self.items2)
80        self.assertEqual(self.s | set(self.items2), i)
81        self.assertEqual(self.s | frozenset(self.items2), i)
82
83    def test_intersection(self):
84        s = WeakSet(self.letters)
85        i = s.intersection(self.items2)
86        for c in self.letters:
87            self.assertEqual(c in i, c in self.items2 and c in self.letters)
88        self.assertEqual(s, WeakSet(self.letters))
89        self.assertEqual(type(i), WeakSet)
90        for C in set, frozenset, dict.fromkeys, list, tuple:
91            x = WeakSet([])
92            self.assertEqual(i.intersection(C(self.items)), x)
93        self.assertEqual(len(i), len(self.items2))
94        self.items2.pop()
95        gc.collect()
96        self.assertEqual(len(i), len(self.items2))
97
98    def test_isdisjoint(self):
99        self.assertTrue(self.s.isdisjoint(WeakSet(self.items2)))
100        self.assertTrue(not self.s.isdisjoint(WeakSet(self.letters)))
101
102    def test_and(self):
103        i = self.s.intersection(self.items2)
104        self.assertEqual(self.s & set(self.items2), i)
105        self.assertEqual(self.s & frozenset(self.items2), i)
106
107    def test_difference(self):
108        i = self.s.difference(self.items2)
109        for c in self.letters:
110            self.assertEqual(c in i, c in self.d and c not in self.items2)
111        self.assertEqual(self.s, WeakSet(self.items))
112        self.assertEqual(type(i), WeakSet)
113        self.assertRaises(TypeError, self.s.difference, [[]])
114
115    def test_sub(self):
116        i = self.s.difference(self.items2)
117        self.assertEqual(self.s - set(self.items2), i)
118        self.assertEqual(self.s - frozenset(self.items2), i)
119
120    def test_symmetric_difference(self):
121        i = self.s.symmetric_difference(self.items2)
122        for c in self.letters:
123            self.assertEqual(c in i, (c in self.d) ^ (c in self.items2))
124        self.assertEqual(self.s, WeakSet(self.items))
125        self.assertEqual(type(i), WeakSet)
126        self.assertRaises(TypeError, self.s.symmetric_difference, [[]])
127        self.assertEqual(len(i), len(self.items) + len(self.items2))
128        self.items2.pop()
129        gc.collect()
130        self.assertEqual(len(i), len(self.items) + len(self.items2))
131
132    def test_xor(self):
133        i = self.s.symmetric_difference(self.items2)
134        self.assertEqual(self.s ^ set(self.items2), i)
135        self.assertEqual(self.s ^ frozenset(self.items2), i)
136
137    def test_sub_and_super(self):
138        self.assertTrue(self.ab_weakset <= self.abcde_weakset)
139        self.assertTrue(self.abcde_weakset <= self.abcde_weakset)
140        self.assertTrue(self.abcde_weakset >= self.ab_weakset)
141        self.assertFalse(self.abcde_weakset <= self.def_weakset)
142        self.assertFalse(self.abcde_weakset >= self.def_weakset)
143        self.assertTrue(set('a').issubset('abc'))
144        self.assertTrue(set('abc').issuperset('a'))
145        self.assertFalse(set('a').issubset('cbs'))
146        self.assertFalse(set('cbs').issuperset('a'))
147
148    def test_lt(self):
149        self.assertTrue(self.ab_weakset < self.abcde_weakset)
150        self.assertFalse(self.abcde_weakset < self.def_weakset)
151        self.assertFalse(self.ab_weakset < self.ab_weakset)
152        self.assertFalse(WeakSet() < WeakSet())
153
154    def test_gt(self):
155        self.assertTrue(self.abcde_weakset > self.ab_weakset)
156        self.assertFalse(self.abcde_weakset > self.def_weakset)
157        self.assertFalse(self.ab_weakset > self.ab_weakset)
158        self.assertFalse(WeakSet() > WeakSet())
159
160    def test_gc(self):
161        # Create a nest of cycles to exercise overall ref count check
162        s = WeakSet(Foo() for i in range(1000))
163        for elem in s:
164            elem.cycle = s
165            elem.sub = elem
166            elem.set = WeakSet([elem])
167
168    def test_subclass_with_custom_hash(self):
169        # Bug #1257731
170        class H(WeakSet):
171            def __hash__(self):
172                return int(id(self) & 0x7fffffff)
173        s=H()
174        f=set()
175        f.add(s)
176        self.assertIn(s, f)
177        f.remove(s)
178        f.add(s)
179        f.discard(s)
180
181    def test_init(self):
182        s = WeakSet()
183        s.__init__(self.items)
184        self.assertEqual(s, self.s)
185        s.__init__(self.items2)
186        self.assertEqual(s, WeakSet(self.items2))
187        self.assertRaises(TypeError, s.__init__, s, 2);
188        self.assertRaises(TypeError, s.__init__, 1);
189
190    def test_constructor_identity(self):
191        s = WeakSet(self.items)
192        t = WeakSet(s)
193        self.assertNotEqual(id(s), id(t))
194
195    def test_hash(self):
196        self.assertRaises(TypeError, hash, self.s)
197
198    def test_clear(self):
199        self.s.clear()
200        self.assertEqual(self.s, WeakSet([]))
201        self.assertEqual(len(self.s), 0)
202
203    def test_copy(self):
204        dup = self.s.copy()
205        self.assertEqual(self.s, dup)
206        self.assertNotEqual(id(self.s), id(dup))
207
208    def test_add(self):
209        x = ustr('Q')
210        self.s.add(x)
211        self.assertIn(x, self.s)
212        dup = self.s.copy()
213        self.s.add(x)
214        self.assertEqual(self.s, dup)
215        self.assertRaises(TypeError, self.s.add, [])
216        self.fs.add(Foo())
217        self.assertTrue(len(self.fs) == 1)
218        self.fs.add(self.obj)
219        self.assertTrue(len(self.fs) == 1)
220
221    def test_remove(self):
222        x = ustr('a')
223        self.s.remove(x)
224        self.assertNotIn(x, self.s)
225        self.assertRaises(KeyError, self.s.remove, x)
226        self.assertRaises(TypeError, self.s.remove, [])
227
228    def test_discard(self):
229        a, q = ustr('a'), ustr('Q')
230        self.s.discard(a)
231        self.assertNotIn(a, self.s)
232        self.s.discard(q)
233        self.assertRaises(TypeError, self.s.discard, [])
234
235    def test_pop(self):
236        for i in range(len(self.s)):
237            elem = self.s.pop()
238            self.assertNotIn(elem, self.s)
239        self.assertRaises(KeyError, self.s.pop)
240
241    def test_update(self):
242        retval = self.s.update(self.items2)
243        self.assertEqual(retval, None)
244        for c in (self.items + self.items2):
245            self.assertIn(c, self.s)
246        self.assertRaises(TypeError, self.s.update, [[]])
247
248    def test_update_set(self):
249        self.s.update(set(self.items2))
250        for c in (self.items + self.items2):
251            self.assertIn(c, self.s)
252
253    def test_ior(self):
254        self.s |= set(self.items2)
255        for c in (self.items + self.items2):
256            self.assertIn(c, self.s)
257
258    def test_intersection_update(self):
259        retval = self.s.intersection_update(self.items2)
260        self.assertEqual(retval, None)
261        for c in (self.items + self.items2):
262            if c in self.items2 and c in self.items:
263                self.assertIn(c, self.s)
264            else:
265                self.assertNotIn(c, self.s)
266        self.assertRaises(TypeError, self.s.intersection_update, [[]])
267
268    def test_iand(self):
269        self.s &= set(self.items2)
270        for c in (self.items + self.items2):
271            if c in self.items2 and c in self.items:
272                self.assertIn(c, self.s)
273            else:
274                self.assertNotIn(c, self.s)
275
276    def test_difference_update(self):
277        retval = self.s.difference_update(self.items2)
278        self.assertEqual(retval, None)
279        for c in (self.items + self.items2):
280            if c in self.items and c not in self.items2:
281                self.assertIn(c, self.s)
282            else:
283                self.assertNotIn(c, self.s)
284        self.assertRaises(TypeError, self.s.difference_update, [[]])
285        self.assertRaises(TypeError, self.s.symmetric_difference_update, [[]])
286
287    def test_isub(self):
288        self.s -= set(self.items2)
289        for c in (self.items + self.items2):
290            if c in self.items and c not in self.items2:
291                self.assertIn(c, self.s)
292            else:
293                self.assertNotIn(c, self.s)
294
295    def test_symmetric_difference_update(self):
296        retval = self.s.symmetric_difference_update(self.items2)
297        self.assertEqual(retval, None)
298        for c in (self.items + self.items2):
299            if (c in self.items) ^ (c in self.items2):
300                self.assertIn(c, self.s)
301            else:
302                self.assertNotIn(c, self.s)
303        self.assertRaises(TypeError, self.s.symmetric_difference_update, [[]])
304
305    def test_ixor(self):
306        self.s ^= set(self.items2)
307        for c in (self.items + self.items2):
308            if (c in self.items) ^ (c in self.items2):
309                self.assertIn(c, self.s)
310            else:
311                self.assertNotIn(c, self.s)
312
313    def test_inplace_on_self(self):
314        t = self.s.copy()
315        t |= t
316        self.assertEqual(t, self.s)
317        t &= t
318        self.assertEqual(t, self.s)
319        t -= t
320        self.assertEqual(t, WeakSet())
321        t = self.s.copy()
322        t ^= t
323        self.assertEqual(t, WeakSet())
324
325    def test_eq(self):
326        # issue 5964
327        self.assertTrue(self.s == self.s)
328        self.assertTrue(self.s == WeakSet(self.items))
329        self.assertFalse(self.s == set(self.items))
330        self.assertFalse(self.s == list(self.items))
331        self.assertFalse(self.s == tuple(self.items))
332        self.assertFalse(self.s == WeakSet([Foo]))
333        self.assertFalse(self.s == 1)
334
335    def test_ne(self):
336        self.assertTrue(self.s != set(self.items))
337        s1 = WeakSet()
338        s2 = WeakSet()
339        self.assertFalse(s1 != s2)
340
341    def test_weak_destroy_while_iterating(self):
342        # Issue #7105: iterators shouldn't crash when a key is implicitly removed
343        # Create new items to be sure no-one else holds a reference
344        items = [ustr(c) for c in ('a', 'b', 'c')]
345        s = WeakSet(items)
346        it = iter(s)
347        next(it)             # Trigger internal iteration
348        # Destroy an item
349        del items[-1]
350        gc.collect()    # just in case
351        # We have removed either the first consumed items, or another one
352        self.assertIn(len(list(it)), [len(items), len(items) - 1])
353        del it
354        # The removal has been committed
355        self.assertEqual(len(s), len(items))
356
357    def test_weak_destroy_and_mutate_while_iterating(self):
358        # Issue #7105: iterators shouldn't crash when a key is implicitly removed
359        items = [ustr(c) for c in string.ascii_letters]
360        s = WeakSet(items)
361        @contextlib.contextmanager
362        def testcontext():
363            try:
364                it = iter(s)
365                # Start iterator
366                yielded = ustr(str(next(it)))
367                # Schedule an item for removal and recreate it
368                u = ustr(str(items.pop()))
369                if yielded == u:
370                    # The iterator still has a reference to the removed item,
371                    # advance it (issue #20006).
372                    next(it)
373                gc.collect()      # just in case
374                yield u
375            finally:
376                it = None           # should commit all removals
377
378        with testcontext() as u:
379            self.assertNotIn(u, s)
380        with testcontext() as u:
381            self.assertRaises(KeyError, s.remove, u)
382        self.assertNotIn(u, s)
383        with testcontext() as u:
384            s.add(u)
385        self.assertIn(u, s)
386        t = s.copy()
387        with testcontext() as u:
388            s.update(t)
389        self.assertEqual(len(s), len(t))
390        with testcontext() as u:
391            s.clear()
392        self.assertEqual(len(s), 0)
393
394    def test_len_cycles(self):
395        N = 20
396        items = [RefCycle() for i in range(N)]
397        s = WeakSet(items)
398        del items
399        it = iter(s)
400        try:
401            next(it)
402        except StopIteration:
403            pass
404        gc.collect()
405        n1 = len(s)
406        del it
407        gc.collect()
408        n2 = len(s)
409        # one item may be kept alive inside the iterator
410        self.assertIn(n1, (0, 1))
411        self.assertEqual(n2, 0)
412
413    def test_len_race(self):
414        # Extended sanity checks for len() in the face of cyclic collection
415        self.addCleanup(gc.set_threshold, *gc.get_threshold())
416        for th in range(1, 100):
417            N = 20
418            gc.collect(0)
419            gc.set_threshold(th, th, th)
420            items = [RefCycle() for i in range(N)]
421            s = WeakSet(items)
422            del items
423            # All items will be collected at next garbage collection pass
424            it = iter(s)
425            try:
426                next(it)
427            except StopIteration:
428                pass
429            n1 = len(s)
430            del it
431            n2 = len(s)
432            self.assertGreaterEqual(n1, 0)
433            self.assertLessEqual(n1, N)
434            self.assertGreaterEqual(n2, 0)
435            self.assertLessEqual(n2, n1)
436
437    def test_repr(self):
438        assert repr(self.s) == repr(self.s.data)
439
440
441if __name__ == "__main__":
442    unittest.main()
443