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
|
require "cases/helper"
require 'models/topic'
require 'models/developer'
require 'models/reply'
require 'models/minimalistic'
class Topic; def after_find() end end
class Developer; def after_find() end end
class SpecialDeveloper < Developer; end
class TopicManualObserver
include Singleton
attr_reader :action, :object, :callbacks
def initialize
Topic.add_observer(self)
@callbacks = []
end
def update(callback_method, object)
@callbacks << { "callback_method" => callback_method, "object" => object }
end
def has_been_notified?
!@callbacks.empty?
end
end
class TopicaAuditor < ActiveRecord::Observer
observe :topic
attr_reader :topic
def after_find(topic)
@topic = topic
end
end
class TopicObserver < ActiveRecord::Observer
attr_reader :topic
def after_find(topic)
@topic = topic
end
end
class MinimalisticObserver < ActiveRecord::Observer
attr_reader :minimalistic
def after_find(minimalistic)
@minimalistic = minimalistic
end
end
class MultiObserver < ActiveRecord::Observer
attr_reader :record
def self.observed_class() [ Topic, Developer ] end
cattr_reader :last_inherited
@@last_inherited = nil
def observed_class_inherited_with_testing(subclass)
observed_class_inherited_without_testing(subclass)
@@last_inherited = subclass
end
alias_method_chain :observed_class_inherited, :testing
def after_find(record)
@record = record
end
end
class LifecycleTest < ActiveRecord::TestCase
fixtures :topics, :developers
def test_before_destroy
original_count = Topic.count
(topic_to_be_destroyed = Topic.find(1)).destroy
assert_equal original_count - (1 + topic_to_be_destroyed.replies.size), Topic.count
end
def test_after_save
ActiveRecord::Base.observers = :topic_manual_observer
ActiveRecord::Base.instantiate_observers
topic = Topic.find(1)
topic.title = "hello"
topic.save
assert TopicManualObserver.instance.has_been_notified?
assert_equal :after_save, TopicManualObserver.instance.callbacks.last["callback_method"]
end
def test_observer_update_on_save
ActiveRecord::Base.observers = TopicManualObserver
ActiveRecord::Base.instantiate_observers
topic = Topic.find(1)
assert TopicManualObserver.instance.has_been_notified?
assert_equal :after_find, TopicManualObserver.instance.callbacks.first["callback_method"]
end
def test_auto_observer
topic_observer = TopicaAuditor.instance
assert_nil TopicaAuditor.observed_class
assert_equal [Topic], TopicaAuditor.instance.observed_classes.to_a
topic = Topic.find(1)
assert_equal topic.title, topic_observer.topic.title
end
def test_inferred_auto_observer
topic_observer = TopicObserver.instance
assert_equal Topic, TopicObserver.observed_class
topic = Topic.find(1)
assert_equal topic.title, topic_observer.topic.title
end
def test_observing_two_classes
multi_observer = MultiObserver.instance
topic = Topic.find(1)
assert_equal topic.title, multi_observer.record.title
developer = Developer.find(1)
assert_equal developer.name, multi_observer.record.name
end
def test_observing_subclasses
multi_observer = MultiObserver.instance
developer = SpecialDeveloper.find(1)
assert_equal developer.name, multi_observer.record.name
klass = Class.new(Developer)
assert_equal klass, multi_observer.last_inherited
developer = klass.find(1)
assert_equal developer.name, multi_observer.record.name
end
def test_after_find_can_be_observed_when_its_not_defined_on_the_model
observer = MinimalisticObserver.instance
assert_equal Minimalistic, MinimalisticObserver.observed_class
minimalistic = Minimalistic.find(1)
assert_equal minimalistic, observer.minimalistic
end
def test_after_find_can_be_observed_when_its_defined_on_the_model
observer = TopicObserver.instance
assert_equal Topic, TopicObserver.observed_class
topic = Topic.find(1)
assert_equal topic, observer.topic
end
def test_after_find_is_not_created_if_its_not_used
# use a fresh class so an observer can't have defined an
# after_find on it
model_class = Class.new(ActiveRecord::Base)
observer_class = Class.new(ActiveRecord::Observer)
observer_class.observe(model_class)
observer = observer_class.instance
assert !model_class.method_defined?(:after_find)
end
def test_after_find_is_not_clobbered_if_it_already_exists
# use a fresh observer class so we can instantiate it (Observer is
# a Singleton)
model_class = Class.new(ActiveRecord::Base) do
def after_find; end
end
original_method = model_class.instance_method(:after_find)
observer_class = Class.new(ActiveRecord::Observer) do
def after_find; end
end
observer_class.observe(model_class)
observer = observer_class.instance
assert_equal original_method, model_class.instance_method(:after_find)
end
def test_invalid_observer
assert_raise(ArgumentError) { Topic.observers = Object.new; Topic.instantiate_observers }
end
end
|
