Source

blinker / tests / test_signals.py

Full commit
  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
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
import gc
import sys
import time

import blinker

from nose.tools import assert_raises


jython = sys.platform.startswith('java')
pypy = hasattr(sys, 'pypy_version_info')


def collect_acyclic_refs():
    # cpython releases these immediately without a collection
    if jython or pypy:
        gc.collect()
    if jython:
        time.sleep(0.1)


class Sentinel(list):
    """A signal receipt accumulator."""

    def make_receiver(self, key):
        """Return a generic signal receiver function logging as *key*

        When connected to a signal, appends (key, sender, kw) to the Sentinel.

        """
        def receiver(*sentby, **kw):
            self.append((key, sentby[0], kw))
        receiver.func_name = 'receiver_%s' % key
        return receiver


def test_meta_connect():
    sentinel = []
    def meta_received(sender, **kw):
        sentinel.append(dict(kw, sender=sender))

    assert not blinker.receiver_connected.receivers
    blinker.receiver_connected.connect(meta_received)
    assert not sentinel

    def receiver(sender, **kw):
        pass
    sig = blinker.Signal()
    sig.connect(receiver)

    assert sentinel == [dict(sender=sig,
                             receiver_arg=receiver,
                             sender_arg=blinker.ANY,
                             weak_arg=True)]

    blinker.receiver_connected._clear_state()


def _test_signal_signals(sender):
    sentinel = Sentinel()
    sig = blinker.Signal()

    connected = sentinel.make_receiver('receiver_connected')
    disconnected = sentinel.make_receiver('receiver_disconnected')
    receiver1 = sentinel.make_receiver('receiver1')
    receiver2 = sentinel.make_receiver('receiver2')

    assert not sig.receiver_connected.receivers
    assert not sig.receiver_disconnected.receivers
    sig.receiver_connected.connect(connected)
    sig.receiver_disconnected.connect(disconnected)

    assert sig.receiver_connected.receivers
    assert not sentinel

    for receiver, weak in [(receiver1, True), (receiver2, False)]:
        sig.connect(receiver, sender=sender, weak=weak)

        expected = ('receiver_connected',
                    sig,
                    dict(receiver=receiver, sender=sender, weak=weak))

        assert sentinel[-1] == expected

    # disconnect from explicit sender
    sig.disconnect(receiver1, sender=sender)

    expected = ('receiver_disconnected',
                sig,
                dict(receiver=receiver1, sender=sender))
    assert sentinel[-1] == expected

    # disconnect from ANY and all senders (implicit disconnect signature)
    sig.disconnect(receiver2)
    assert sentinel[-1] == ('receiver_disconnected',
                            sig,
                            dict(receiver=receiver2, sender=blinker.ANY))


def test_signal_signals_any_sender():
    _test_signal_signals(blinker.ANY)


def test_signal_signals_strong_sender():
    _test_signal_signals("squiznart")


def test_signal_weak_receiver_vanishes():
    # non-edge-case path for weak receivers is exercised in the ANY sender
    # test above.
    sentinel = Sentinel()
    sig = blinker.Signal()

    connected = sentinel.make_receiver('receiver_connected')
    disconnected = sentinel.make_receiver('receiver_disconnected')
    receiver1 = sentinel.make_receiver('receiver1')
    receiver2 = sentinel.make_receiver('receiver2')

    sig.receiver_connected.connect(connected)
    sig.receiver_disconnected.connect(disconnected)

    # explicit disconnect on a weak does emit the signal
    sig.connect(receiver1, weak=True)
    sig.disconnect(receiver1)

    assert len(sentinel) == 2
    assert sentinel[-1][2]['receiver'] is receiver1

    del sentinel[:]
    sig.connect(receiver2, weak=True)
    assert len(sentinel) == 1

    del sentinel[:]  # holds a ref to receiver2
    del receiver2
    collect_acyclic_refs()

    # no disconnect signal is fired
    assert len(sentinel) == 0

    # and everything really is disconnected
    sig.send('abc')
    assert len(sentinel) == 0


def test_signal_signals_weak_sender():
    sentinel = Sentinel()
    sig = blinker.Signal()

    connected = sentinel.make_receiver('receiver_connected')
    disconnected = sentinel.make_receiver('receiver_disconnected')
    receiver1 = sentinel.make_receiver('receiver1')
    receiver2 = sentinel.make_receiver('receiver2')

    class Sender(object):
        """A weakref-able object."""

    sig.receiver_connected.connect(connected)
    sig.receiver_disconnected.connect(disconnected)

    sender1 = Sender()
    sig.connect(receiver1, sender=sender1, weak=False)
    # regular disconnect of weak-able sender works fine
    sig.disconnect(receiver1, sender=sender1)

    assert len(sentinel) == 2

    del sentinel[:]
    sender2 = Sender()
    sig.connect(receiver2, sender=sender2, weak=False)

    # force sender2 to go out of scope
    del sender2
    collect_acyclic_refs()

    # no disconnect signal is fired
    assert len(sentinel) == 1

    # and everything really is disconnected
    sig.send('abc')
    assert len(sentinel) == 1


def test_meta_connect_failure():
    def meta_received(sender, **kw):
        raise TypeError('boom')

    assert not blinker.receiver_connected.receivers
    blinker.receiver_connected.connect(meta_received)

    def receiver(sender, **kw):
        pass
    sig = blinker.Signal()

    assert_raises(TypeError, sig.connect, receiver)
    assert not sig.receivers
    assert not sig._by_receiver
    assert sig._by_sender == {blinker.base.ANY_ID: set()}

    blinker.receiver_connected._clear_state()


def test_singletons():
    ns = blinker.Namespace()
    assert not ns
    s1 = ns.signal('abc')
    assert s1 is ns.signal('abc')
    assert s1 is not ns.signal('def')
    assert 'abc' in ns
    collect_acyclic_refs()

    # weak by default, already out of scope
    assert 'def' not in ns
    del s1
    collect_acyclic_refs()

    assert 'abc' not in ns


def test_weak_receiver():
    sentinel = []
    def received(sender, **kw):
        sentinel.append(kw)

    sig = blinker.Signal()

    # XXX: weirdly, under jython an explicit weak=True causes this test
    #      to fail, leaking a strong ref to the receiver somewhere.
    #      http://bugs.jython.org/issue1586
    if jython:
        sig.connect(received)  # weak=True by default.
    else:
        sig.connect(received, weak=True)

    del received
    collect_acyclic_refs()

    assert not sentinel
    sig.send()
    assert not sentinel
    assert not sig.receivers
    values_are_empty_sets_(sig._by_receiver)
    values_are_empty_sets_(sig._by_sender)


def test_strong_receiver():
    sentinel = []
    def received(sender):
        sentinel.append(sender)
    fn_id = id(received)

    sig = blinker.Signal()
    sig.connect(received, weak=False)

    del received
    collect_acyclic_refs()

    assert not sentinel
    sig.send()
    assert sentinel
    assert [id(fn) for fn in sig.receivers.values()] == [fn_id]


def test_instancemethod_receiver():
    sentinel = []

    class Receiver(object):
        def __init__(self, bucket):
            self.bucket = bucket
        def received(self, sender):
            self.bucket.append(sender)

    receiver = Receiver(sentinel)

    sig = blinker.Signal()
    sig.connect(receiver.received)

    assert not sentinel
    sig.send()
    assert sentinel
    del receiver
    collect_acyclic_refs()

    sig.send()
    assert len(sentinel) == 1


def test_filtered_receiver():
    sentinel = []
    def received(sender):
        sentinel.append(sender)

    sig = blinker.Signal()

    sig.connect(received, 123)

    assert not sentinel
    sig.send()
    assert not sentinel
    sig.send(123)
    assert sentinel == [123]
    sig.send()
    assert sentinel == [123]

    sig.disconnect(received, 123)
    sig.send(123)
    assert sentinel == [123]

    sig.connect(received, 123)
    sig.send(123)
    assert sentinel == [123, 123]

    sig.disconnect(received)
    sig.send(123)
    assert sentinel == [123, 123]


def test_filtered_receiver_weakref():
    sentinel = []
    def received(sender):
        sentinel.append(sender)

    class Object(object):
        pass
    obj = Object()

    sig = blinker.Signal()
    sig.connect(received, obj)

    assert not sentinel
    sig.send(obj)
    assert sentinel == [obj]
    del sentinel[:]
    del obj
    collect_acyclic_refs()

    # general index isn't cleaned up
    assert sig.receivers
    # but receiver/sender pairs are
    values_are_empty_sets_(sig._by_receiver)
    values_are_empty_sets_(sig._by_sender)


def test_decorated_receiver():
    sentinel = []

    class Object(object):
        pass
    obj = Object()

    sig = blinker.Signal()

    @sig.connect_via(obj)
    def receiver(sender, **kw):
        sentinel.append(kw)

    assert not sentinel
    sig.send()
    assert not sentinel
    sig.send(1)
    assert not sentinel
    sig.send(obj)
    assert sig.receivers

    del receiver
    collect_acyclic_refs()
    assert sig.receivers


def test_no_double_send():
    sentinel = []
    def received(sender):
        sentinel.append(sender)

    sig = blinker.Signal()

    sig.connect(received, 123)
    sig.connect(received)

    assert not sentinel
    sig.send()
    assert sentinel == [None]
    sig.send(123)
    assert sentinel == [None, 123]
    sig.send()
    assert sentinel == [None, 123, None]


def test_has_receivers():
    received = lambda sender: None

    sig = blinker.Signal()
    assert not sig.has_receivers_for(None)
    assert not sig.has_receivers_for(blinker.ANY)

    sig.connect(received, 'xyz')
    assert not sig.has_receivers_for(None)
    assert not sig.has_receivers_for(blinker.ANY)
    assert sig.has_receivers_for('xyz')

    class Object(object):
        pass
    o = Object()

    sig.connect(received, o)
    assert sig.has_receivers_for(o)

    del received
    collect_acyclic_refs()

    assert not sig.has_receivers_for('xyz')
    assert list(sig.receivers_for('xyz')) == []
    assert list(sig.receivers_for(o)) == []

    sig.connect(lambda sender: None, weak=False)
    assert sig.has_receivers_for('xyz')
    assert sig.has_receivers_for(o)
    assert sig.has_receivers_for(None)
    assert sig.has_receivers_for(blinker.ANY)
    assert sig.has_receivers_for('xyz')


def test_instance_doc():
    sig = blinker.Signal(doc='x')
    assert sig.__doc__ == 'x'

    sig = blinker.Signal('x')
    assert sig.__doc__ == 'x'


def test_named_blinker():
    sig = blinker.NamedSignal('squiznart')
    assert 'squiznart' in repr(sig)


def values_are_empty_sets_(dictionary):
    for val in dictionary.values():
        assert val == set()

if sys.version_info < (2, 5):
    def test_context_manager_warning():
        sig = blinker.Signal()
        receiver = lambda sender: None

        assert_raises(RuntimeError, sig.temporarily_connected_to, receiver)