--- /dev/null
+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, :minimalistics
+
+ 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