summaryrefslogtreecommitdiff
path: root/tests/test_gobject.py
blob: 57d38220265ed771889bca8c04923800949afd19 (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
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
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
# -*- Mode: Python -*-

import sys
import gc
import unittest
import warnings

from gi.repository import GObject, GLib
from gi import PyGIDeprecationWarning
from gi.module import get_introspection_module
from gi._gobject import _gobject

import testhelper


class TestGObjectAPI(unittest.TestCase):
    def test_gobject_inheritance(self):
        # GObject.Object is a class hierarchy as follows:
        # overrides.Object -> introspection.Object -> static.GObject
        GIObjectModule = get_introspection_module('GObject')
        self.assertTrue(issubclass(GObject.Object, GIObjectModule.Object))
        self.assertTrue(issubclass(GIObjectModule.Object, _gobject.GObject))

        self.assertEqual(_gobject.GObject.__gtype__, GObject.TYPE_OBJECT)
        self.assertEqual(GIObjectModule.Object.__gtype__, GObject.TYPE_OBJECT)
        self.assertEqual(GObject.Object.__gtype__, GObject.TYPE_OBJECT)

        # The pytype wrapper should hold the outer most Object class from overrides.
        self.assertEqual(GObject.TYPE_OBJECT.pytype, GObject.Object)

    def test_gobject_unsupported_overrides(self):
        obj = GObject.Object()

        with self.assertRaisesRegex(RuntimeError, 'Data access methods are unsupported.*'):
            obj.get_data()

        with self.assertRaisesRegex(RuntimeError, 'This method is currently unsupported.*'):
            obj.force_floating()

    def test_compat_api(self):
        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter('always')
            # GObject formerly exposed a lot of GLib's functions
            self.assertEqual(GObject.markup_escape_text('foo'), 'foo')

            ml = GObject.MainLoop()
            self.assertFalse(ml.is_running())

            context = GObject.main_context_default()
            self.assertTrue(context.pending() in [False, True])

            context = GObject.MainContext()
            self.assertFalse(context.pending())

            self.assertTrue(issubclass(w[0].category, PyGIDeprecationWarning))
            self.assertTrue('GLib.markup_escape_text' in str(w[0]), str(w[0]))

            self.assertLess(GObject.PRIORITY_HIGH, GObject.PRIORITY_DEFAULT)

    def test_min_max_int(self):
        self.assertEqual(GObject.G_MAXINT16, 2 ** 15 - 1)
        self.assertEqual(GObject.G_MININT16, -2 ** 15)
        self.assertEqual(GObject.G_MAXUINT16, 2 ** 16 - 1)

        self.assertEqual(GObject.G_MAXINT32, 2 ** 31 - 1)
        self.assertEqual(GObject.G_MININT32, -2 ** 31)
        self.assertEqual(GObject.G_MAXUINT32, 2 ** 32 - 1)

        self.assertEqual(GObject.G_MAXINT64, 2 ** 63 - 1)
        self.assertEqual(GObject.G_MININT64, -2 ** 63)
        self.assertEqual(GObject.G_MAXUINT64, 2 ** 64 - 1)


class TestReferenceCounting(unittest.TestCase):
    def test_regular_object(self):
        obj = GObject.GObject()
        self.assertEqual(obj.__grefcount__, 1)

        obj = GObject.new(GObject.GObject)
        self.assertEqual(obj.__grefcount__, 1)

    def test_floating(self):
        obj = testhelper.Floating()
        self.assertEqual(obj.__grefcount__, 1)

        obj = GObject.new(testhelper.Floating)
        self.assertEqual(obj.__grefcount__, 1)

    def test_owned_by_library(self):
        # Upon creation, the refcount of the object should be 2:
        # - someone already has a reference on the new object.
        # - the python wrapper should hold its own reference.
        obj = testhelper.OwnedByLibrary()
        self.assertEqual(obj.__grefcount__, 2)

        # We ask the library to release its reference, so the only
        # remaining ref should be our wrapper's. Once the wrapper
        # will run out of scope, the object will get finalized.
        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_owned_by_library_out_of_scope(self):
        obj = testhelper.OwnedByLibrary()
        self.assertEqual(obj.__grefcount__, 2)

        # We are manually taking the object out of scope. This means
        # that our wrapper has been freed, and its reference dropped. We
        # cannot check it but the refcount should now be 1 (the ref held
        # by the library is still there, we didn't call release()
        obj = None

        # When we get the object back from the lib, the wrapper is
        # re-created, so our refcount will be 2 once again.
        obj = testhelper.owned_by_library_get_instance_list()[0]
        self.assertEqual(obj.__grefcount__, 2)

        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_owned_by_library_using_gobject_new(self):
        # Upon creation, the refcount of the object should be 2:
        # - someone already has a reference on the new object.
        # - the python wrapper should hold its own reference.
        obj = GObject.new(testhelper.OwnedByLibrary)
        self.assertEqual(obj.__grefcount__, 2)

        # We ask the library to release its reference, so the only
        # remaining ref should be our wrapper's. Once the wrapper
        # will run out of scope, the object will get finalized.
        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_owned_by_library_out_of_scope_using_gobject_new(self):
        obj = GObject.new(testhelper.OwnedByLibrary)
        self.assertEqual(obj.__grefcount__, 2)

        # We are manually taking the object out of scope. This means
        # that our wrapper has been freed, and its reference dropped. We
        # cannot check it but the refcount should now be 1 (the ref held
        # by the library is still there, we didn't call release()
        obj = None

        # When we get the object back from the lib, the wrapper is
        # re-created, so our refcount will be 2 once again.
        obj = testhelper.owned_by_library_get_instance_list()[0]
        self.assertEqual(obj.__grefcount__, 2)

        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_floating_and_sunk(self):
        # Upon creation, the refcount of the object should be 2:
        # - someone already has a reference on the new object.
        # - the python wrapper should hold its own reference.
        obj = testhelper.FloatingAndSunk()
        self.assertEqual(obj.__grefcount__, 2)

        # We ask the library to release its reference, so the only
        # remaining ref should be our wrapper's. Once the wrapper
        # will run out of scope, the object will get finalized.
        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_floating_and_sunk_out_of_scope(self):
        obj = testhelper.FloatingAndSunk()
        self.assertEqual(obj.__grefcount__, 2)

        # We are manually taking the object out of scope. This means
        # that our wrapper has been freed, and its reference dropped. We
        # cannot check it but the refcount should now be 1 (the ref held
        # by the library is still there, we didn't call release()
        obj = None

        # When we get the object back from the lib, the wrapper is
        # re-created, so our refcount will be 2 once again.
        obj = testhelper.floating_and_sunk_get_instance_list()[0]
        self.assertEqual(obj.__grefcount__, 2)

        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_floating_and_sunk_using_gobject_new(self):
        # Upon creation, the refcount of the object should be 2:
        # - someone already has a reference on the new object.
        # - the python wrapper should hold its own reference.
        obj = GObject.new(testhelper.FloatingAndSunk)
        self.assertEqual(obj.__grefcount__, 2)

        # We ask the library to release its reference, so the only
        # remaining ref should be our wrapper's. Once the wrapper
        # will run out of scope, the object will get finalized.
        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_floating_and_sunk_out_of_scope_using_gobject_new(self):
        obj = GObject.new(testhelper.FloatingAndSunk)
        self.assertEqual(obj.__grefcount__, 2)

        # We are manually taking the object out of scope. This means
        # that our wrapper has been freed, and its reference dropped. We
        # cannot check it but the refcount should now be 1 (the ref held
        # by the library is still there, we didn't call release()
        obj = None

        # When we get the object back from the lib, the wrapper is
        # re-created, so our refcount will be 2 once again.
        obj = testhelper.floating_and_sunk_get_instance_list()[0]
        self.assertEqual(obj.__grefcount__, 2)

        obj.release()
        self.assertEqual(obj.__grefcount__, 1)

    def test_uninitialized_object(self):
        class Obj(GObject.GObject):
            def __init__(self):
                x = self.__grefcount__
                super(Obj, self).__init__()
                assert x >= 0  # quiesce pyflakes

        # Accessing __grefcount__ before the object is initialized is wrong.
        # Ensure we get a proper exception instead of a crash.
        self.assertRaises(TypeError, Obj)


class A(GObject.GObject):
    def __init__(self):
        super(A, self).__init__()


class TestPythonReferenceCounting(unittest.TestCase):
    # Newly created instances should alwayshave two references: one for
    # the GC, and one for the bound variable in the local scope.

    def test_new_instance_has_two_refs(self):
        obj = GObject.GObject()
        self.assertEqual(sys.getrefcount(obj), 2)

    def test_new_instance_has_two_refs_using_gobject_new(self):
        obj = GObject.new(GObject.GObject)
        self.assertEqual(sys.getrefcount(obj), 2)

    def test_new_subclass_instance_has_two_refs(self):
        obj = A()
        self.assertEqual(sys.getrefcount(obj), 2)

    def test_new_subclass_instance_has_two_refs_using_gobject_new(self):
        obj = GObject.new(A)
        self.assertEqual(sys.getrefcount(obj), 2)


class TestContextManagers(unittest.TestCase):
    class ContextTestObject(GObject.GObject):
        prop = GObject.Property(default=0, type=int)

    def on_prop_set(self, obj, prop):
        # Handler which tracks property changed notifications.
        self.tracking.append(obj.get_property(prop.name))

    def setUp(self):
        self.tracking = []
        self.obj = self.ContextTestObject()
        self.handler = self.obj.connect('notify::prop', self.on_prop_set)

    def test_freeze_notify_context(self):
        # Verify prop tracking list
        self.assertEqual(self.tracking, [])
        self.obj.props.prop = 1
        self.assertEqual(self.tracking, [1])
        self.obj.props.prop = 2
        self.assertEqual(self.tracking, [1, 2])
        self.assertEqual(self.obj.__grefcount__, 1)

        pyref_count = sys.getrefcount(self.obj)

        # Using the context manager the tracking list should not be affected.
        # The GObject reference count should stay the same and the python
        # object ref-count should go up.
        with self.obj.freeze_notify():
            self.assertEqual(self.obj.__grefcount__, 1)
            self.assertEqual(sys.getrefcount(self.obj), pyref_count + 1)
            self.obj.props.prop = 3
            self.assertEqual(self.obj.props.prop, 3)
            self.assertEqual(self.tracking, [1, 2])

        # After the context manager, the prop should have been modified,
        # the tracking list will be modified, and the python object ref
        # count goes back down.
        gc.collect()
        self.assertEqual(self.obj.props.prop, 3)
        self.assertEqual(self.tracking, [1, 2, 3])
        self.assertEqual(self.obj.__grefcount__, 1)
        self.assertEqual(sys.getrefcount(self.obj), pyref_count)

    def test_handler_block_context(self):
        # Verify prop tracking list
        self.assertEqual(self.tracking, [])
        self.obj.props.prop = 1
        self.assertEqual(self.tracking, [1])
        self.obj.props.prop = 2
        self.assertEqual(self.tracking, [1, 2])
        self.assertEqual(self.obj.__grefcount__, 1)

        pyref_count = sys.getrefcount(self.obj)

        # Using the context manager the tracking list should not be affected.
        # The GObject reference count should stay the same and the python
        # object ref-count should go up.
        with self.obj.handler_block(self.handler):
            self.assertEqual(self.obj.__grefcount__, 1)
            self.assertEqual(sys.getrefcount(self.obj), pyref_count + 1)
            self.obj.props.prop = 3
            self.assertEqual(self.obj.props.prop, 3)
            self.assertEqual(self.tracking, [1, 2])

        # After the context manager, the prop should have been modified
        # the tracking list should have stayed the same and the GObject ref
        # count goes back down.
        gc.collect()
        self.assertEqual(self.obj.props.prop, 3)
        self.assertEqual(self.tracking, [1, 2])
        self.assertEqual(self.obj.__grefcount__, 1)
        self.assertEqual(sys.getrefcount(self.obj), pyref_count)

    def test_freeze_notify_context_nested(self):
        self.assertEqual(self.tracking, [])
        with self.obj.freeze_notify():
            self.obj.props.prop = 1
            self.assertEqual(self.tracking, [])

            with self.obj.freeze_notify():
                self.obj.props.prop = 2
                self.assertEqual(self.tracking, [])

                with self.obj.freeze_notify():
                    self.obj.props.prop = 3
                    self.assertEqual(self.tracking, [])
                self.assertEqual(self.tracking, [])
            self.assertEqual(self.tracking, [])

        # Finally after last context, the notifications should have collapsed
        # and the last one sent.
        self.assertEqual(self.tracking, [3])

    def test_handler_block_context_nested(self):
        self.assertEqual(self.tracking, [])
        with self.obj.handler_block(self.handler):
            self.obj.props.prop = 1
            self.assertEqual(self.tracking, [])

            with self.obj.handler_block(self.handler):
                self.obj.props.prop = 2
                self.assertEqual(self.tracking, [])

                with self.obj.handler_block(self.handler):
                    self.obj.props.prop = 3
                    self.assertEqual(self.tracking, [])
                self.assertEqual(self.tracking, [])
            self.assertEqual(self.tracking, [])

        # Finally after last context, the notifications should have collapsed
        # and the last one sent.
        self.assertEqual(self.obj.props.prop, 3)
        self.assertEqual(self.tracking, [])

    def test_freeze_notify_normal_usage_ref_counts(self):
        # Ensure ref counts without using methods as context managers
        # maintain the same count.
        self.assertEqual(self.obj.__grefcount__, 1)
        self.obj.freeze_notify()
        self.assertEqual(self.obj.__grefcount__, 1)
        self.obj.thaw_notify()
        self.assertEqual(self.obj.__grefcount__, 1)

    def test_handler_block_normal_usage_ref_counts(self):
        self.assertEqual(self.obj.__grefcount__, 1)
        self.obj.handler_block(self.handler)
        self.assertEqual(self.obj.__grefcount__, 1)
        self.obj.handler_unblock(self.handler)
        self.assertEqual(self.obj.__grefcount__, 1)

    def test_freeze_notify_context_error(self):
        # Test an exception occurring within a freeze context exits the context
        try:
            with self.obj.freeze_notify():
                self.obj.props.prop = 1
                self.assertEqual(self.tracking, [])
                raise ValueError('Simulation')
        except ValueError:
            pass

        # Verify the property set within the context called notify.
        self.assertEqual(self.obj.props.prop, 1)
        self.assertEqual(self.tracking, [1])

        # Verify we are still not in a frozen context.
        self.obj.props.prop = 2
        self.assertEqual(self.tracking, [1, 2])

    def test_handler_block_context_error(self):
        # Test an exception occurring within a handler block exits the context
        try:
            with self.obj.handler_block(self.handler):
                self.obj.props.prop = 1
                self.assertEqual(self.tracking, [])
                raise ValueError('Simulation')
        except ValueError:
            pass

        # Verify the property set within the context didn't call notify.
        self.assertEqual(self.obj.props.prop, 1)
        self.assertEqual(self.tracking, [])

        # Verify we are still not in a handler block context.
        self.obj.props.prop = 2
        self.assertEqual(self.tracking, [2])


class TestPropertyBindings(unittest.TestCase):
    class TestObject(GObject.GObject):
        int_prop = GObject.Property(default=0, type=int)

    def setUp(self):
        self.source = self.TestObject()
        self.target = self.TestObject()

    def test_default_binding(self):
        binding = self.source.bind_property('int_prop', self.target, 'int_prop',
                                            GObject.BindingFlags.DEFAULT)
        binding = binding  # PyFlakes

        # Test setting value on source gets pushed to target
        self.source.int_prop = 1
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 1)

        # Test setting value on target does not change source
        self.target.props.int_prop = 2
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 2)

    def test_bidirectional_binding(self):
        binding = self.source.bind_property('int_prop', self.target, 'int_prop',
                                            GObject.BindingFlags.BIDIRECTIONAL)
        binding = binding  # PyFlakes

        # Test setting value on source gets pushed to target
        self.source.int_prop = 1
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 1)

        # Test setting value on target also changes source
        self.target.props.int_prop = 2
        self.assertEqual(self.source.int_prop, 2)
        self.assertEqual(self.target.int_prop, 2)

    def test_transform_to_only(self):
        def transform_to(binding, value, user_data=None):
            self.assertEqual(user_data, 'test-data')
            return value * 2

        binding = self.source.bind_property('int_prop', self.target, 'int_prop',
                                            GObject.BindingFlags.DEFAULT,
                                            transform_to, None, 'test-data')
        binding = binding  # PyFlakes

        self.source.int_prop = 1
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 2)

        self.target.props.int_prop = 1
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 1)

    def test_transform_from_only(self):
        def transform_from(binding, value, user_data=None):
            self.assertEqual(user_data, None)
            return value * 2

        binding = self.source.bind_property('int_prop', self.target, 'int_prop',
                                            GObject.BindingFlags.BIDIRECTIONAL,
                                            None, transform_from)
        binding = binding  # PyFlakes

        self.source.int_prop = 1
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 1)

        self.target.props.int_prop = 1
        self.assertEqual(self.source.int_prop, 2)
        self.assertEqual(self.target.int_prop, 1)

    def test_transform_bidirectional(self):
        test_data = object()

        def transform_to(binding, value, user_data=None):
            self.assertEqual(user_data, test_data)
            return value * 2

        def transform_from(binding, value, user_data=None):
            self.assertEqual(user_data, test_data)
            return value // 2

        test_data_ref_count = sys.getrefcount(test_data)
        transform_to_ref_count = sys.getrefcount(transform_to)
        transform_from_ref_count = sys.getrefcount(transform_from)

        # bidirectional bindings
        binding = self.source.bind_property('int_prop', self.target, 'int_prop',
                                            GObject.BindingFlags.BIDIRECTIONAL,
                                            transform_to, transform_from, test_data)
        binding = binding  # PyFlakes
        binding_ref_count = sys.getrefcount(binding())
        binding_gref_count = binding().__grefcount__

        self.source.int_prop = 1
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 2)

        self.target.props.int_prop = 4
        self.assertEqual(self.source.int_prop, 2)
        self.assertEqual(self.target.int_prop, 4)

        self.assertEqual(sys.getrefcount(binding()), binding_ref_count)
        self.assertEqual(binding().__grefcount__, binding_gref_count)

        # test_data ref count increases by 2, once for each callback.
        self.assertEqual(sys.getrefcount(test_data), test_data_ref_count + 2)
        self.assertEqual(sys.getrefcount(transform_to), transform_to_ref_count + 1)
        self.assertEqual(sys.getrefcount(transform_from), transform_from_ref_count + 1)

        # Unbind should clear out the binding and its transforms
        binding.unbind()
        self.assertEqual(binding(), None)
        del binding
        gc.collect()

        # Setting source or target should not change the other.
        self.target.int_prop = 3
        self.source.int_prop = 5
        self.assertEqual(self.target.int_prop, 3)
        self.assertEqual(self.source.int_prop, 5)

        self.assertEqual(sys.getrefcount(test_data), test_data_ref_count)
        self.assertEqual(sys.getrefcount(transform_to), transform_to_ref_count)
        self.assertEqual(sys.getrefcount(transform_from), transform_from_ref_count)

    def test_explicit_unbind_clears_connection(self):
        self.assertEqual(self.source.int_prop, 0)
        self.assertEqual(self.target.int_prop, 0)

        # Test deleting binding reference removes binding.
        binding = self.source.bind_property('int_prop', self.target, 'int_prop')
        self.source.int_prop = 1
        self.assertEqual(self.source.int_prop, 1)
        self.assertEqual(self.target.int_prop, 1)

        binding.unbind()
        self.assertEqual(binding(), None)

        self.source.int_prop = 10
        self.assertEqual(self.source.int_prop, 10)
        self.assertEqual(self.target.int_prop, 1)

        # An already unbound BindingWeakRef will raise if unbind is attempted a second time.
        self.assertRaises(ValueError, binding.unbind)

    def test_reference_counts(self):
        self.assertEqual(self.source.__grefcount__, 1)
        self.assertEqual(self.target.__grefcount__, 1)

        # Binding ref count will be 2 do to the initial ref implicitly held by
        # the act of binding and the ref incurred by using __call__ to generate
        # a wrapper from the weak binding ref within python.
        binding = self.source.bind_property('int_prop', self.target, 'int_prop')
        self.assertEqual(binding().__grefcount__, 2)

        # Creating a binding does not inc refs on source and target (they are weak
        # on the binding object itself)
        self.assertEqual(self.source.__grefcount__, 1)
        self.assertEqual(self.target.__grefcount__, 1)

        # Use GObject.get_property because the "props" accessor leaks.
        # Note property names are canonicalized.
        self.assertEqual(binding().get_property('source'), self.source)
        self.assertEqual(binding().get_property('source_property'), 'int-prop')
        self.assertEqual(binding().get_property('target'), self.target)
        self.assertEqual(binding().get_property('target_property'), 'int-prop')
        self.assertEqual(binding().get_property('flags'), GObject.BindingFlags.DEFAULT)

        # Delete reference to source or target and the binding should listen.
        ref = self.source.weak_ref()
        del self.source
        gc.collect()
        self.assertEqual(ref(), None)
        self.assertEqual(binding(), None)


class TestGValue(unittest.TestCase):
    def test_type_constant(self):
        self.assertEqual(GObject.TYPE_VALUE, GObject.Value.__gtype__)
        self.assertEqual(GObject.type_name(GObject.TYPE_VALUE), 'GValue')

    def test_no_type(self):
        value = GObject.Value()
        self.assertEqual(value.g_type, GObject.TYPE_INVALID)
        self.assertRaises(TypeError, value.set_value, 23)
        self.assertEqual(value.get_value(), None)

    def test_int(self):
        value = GObject.Value(GObject.TYPE_UINT)
        self.assertEqual(value.g_type, GObject.TYPE_UINT)
        value.set_value(23)
        self.assertEqual(value.get_value(), 23)
        value.set_value(42.0)
        self.assertEqual(value.get_value(), 42)

    def test_string(self):
        value = GObject.Value(str, 'foo_bar')
        self.assertEqual(value.g_type, GObject.TYPE_STRING)
        self.assertEqual(value.get_value(), 'foo_bar')

    def test_float(self):
        # python float is G_TYPE_DOUBLE
        value = GObject.Value(float, 23.4)
        self.assertEqual(value.g_type, GObject.TYPE_DOUBLE)
        value.set_value(1e50)
        self.assertAlmostEqual(value.get_value(), 1e50)

        value = GObject.Value(GObject.TYPE_FLOAT, 23.4)
        self.assertEqual(value.g_type, GObject.TYPE_FLOAT)
        self.assertRaises(TypeError, value.set_value, 'string')
        self.assertRaises(OverflowError, value.set_value, 1e50)

    def test_float_inf_nan(self):
        nan = float('nan')
        for type_ in [GObject.TYPE_FLOAT, GObject.TYPE_DOUBLE]:
            for x in [float('inf'), float('-inf'), nan]:
                value = GObject.Value(type_, x)
                # assertEqual() is False for (nan, nan)
                if x is nan:
                    self.assertEqual(str(value.get_value()), 'nan')
                else:
                    self.assertEqual(value.get_value(), x)

    def test_enum(self):
        value = GObject.Value(GLib.FileError, GLib.FileError.FAILED)
        self.assertEqual(value.get_value(), GLib.FileError.FAILED)

    def test_flags(self):
        value = GObject.Value(GLib.IOFlags, GLib.IOFlags.IS_READABLE)
        self.assertEqual(value.get_value(), GLib.IOFlags.IS_READABLE)

    def test_object(self):
        class TestObject(GObject.Object):
            pass
        obj = TestObject()
        value = GObject.Value(GObject.TYPE_OBJECT, obj)
        self.assertEqual(value.get_value(), obj)

if __name__ == '__main__':
    unittest.main()