6 files changed, 132 insertions, 0 deletions
diff --git a/spec/ruby/library/observer/add_observer_spec.rb b/spec/ruby/library/observer/add_observer_spec.rb
new file mode 100644
index 0000000000..5217ae6dc4
--- /dev/null
+++ b/spec/ruby/library/observer/add_observer_spec.rb
@@ -0,0 +1,23 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Observer#add_observer" do
+
+  before :each do
+    @observable = ObservableSpecs.new
+    @observer = ObserverCallbackSpecs.new
+  end
+
+  it "adds the observer" do
+    @observer.value.should == nil
+    @observable.changed
+    @observable.notify_observers("test")
+    @observer.value.should == nil
+
+    @observable.add_observer(@observer)
+    @observable.changed
+    @observable.notify_observers("test2")
+    @observer.value.should == "test2"
+  end
+
+end
diff --git a/spec/ruby/library/observer/count_observers_spec.rb b/spec/ruby/library/observer/count_observers_spec.rb
new file mode 100644
index 0000000000..c93674196d
--- /dev/null
+++ b/spec/ruby/library/observer/count_observers_spec.rb
@@ -0,0 +1,23 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Observer#count_observers" do
+  before :each do
+    @observable = ObservableSpecs.new
+    @observer   = ObserverCallbackSpecs.new
+    @observer2  = ObserverCallbackSpecs.new
+  end
+
+  it "returns the number of observers" do
+    @observable.count_observers.should == 0
+    @observable.add_observer(@observer)
+    @observable.count_observers.should == 1
+    @observable.add_observer(@observer2)
+    @observable.count_observers.should == 2
+  end
+
+  it "returns the number of unique observers" do
+    2.times { @observable.add_observer(@observer) }
+    @observable.count_observers.should == 1
+  end
+end
diff --git a/spec/ruby/library/observer/delete_observer_spec.rb b/spec/ruby/library/observer/delete_observer_spec.rb
new file mode 100644
index 0000000000..52be1a6cba
--- /dev/null
+++ b/spec/ruby/library/observer/delete_observer_spec.rb
@@ -0,0 +1,19 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Observer#delete_observer" do
+  before :each do
+    @observable = ObservableSpecs.new
+    @observer = ObserverCallbackSpecs.new
+  end
+
+  it "deletes the observer" do
+    @observable.add_observer(@observer)
+    @observable.delete_observer(@observer)
+
+    @observable.changed
+    @observable.notify_observers("test")
+    @observer.value.should == nil
+  end
+
+end
diff --git a/spec/ruby/library/observer/delete_observers_spec.rb b/spec/ruby/library/observer/delete_observers_spec.rb
new file mode 100644
index 0000000000..186e93a013
--- /dev/null
+++ b/spec/ruby/library/observer/delete_observers_spec.rb
@@ -0,0 +1,19 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Observer#delete_observers" do
+  before :each do
+    @observable = ObservableSpecs.new
+    @observer = ObserverCallbackSpecs.new
+  end
+
+  it "deletes the observers" do
+    @observable.add_observer(@observer)
+    @observable.delete_observers
+
+    @observable.changed
+    @observable.notify_observers("test")
+    @observer.value.should == nil
+  end
+
+end
diff --git a/spec/ruby/library/observer/fixtures/classes.rb b/spec/ruby/library/observer/fixtures/classes.rb
new file mode 100644
index 0000000000..70cd1b1be2
--- /dev/null
+++ b/spec/ruby/library/observer/fixtures/classes.rb
@@ -0,0 +1,17 @@
+require 'observer'
+
+class ObserverCallbackSpecs
+  attr_reader :value
+
+  def initialize
+    @value = nil
+  end
+
+  def update(value)
+    @value = value
+  end
+end
+
+class ObservableSpecs
+  include Observable
+end
diff --git a/spec/ruby/library/observer/notify_observers_spec.rb b/spec/ruby/library/observer/notify_observers_spec.rb
new file mode 100644
index 0000000000..6f3f984637
--- /dev/null
+++ b/spec/ruby/library/observer/notify_observers_spec.rb
@@ -0,0 +1,31 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Observer#notify_observers" do
+
+  before :each do
+    @observable = ObservableSpecs.new
+    @observer = ObserverCallbackSpecs.new
+    @observable.add_observer(@observer)
+  end
+
+  it "must call changed before notifying observers" do
+    @observer.value.should == nil
+    @observable.notify_observers("test")
+    @observer.value.should == nil
+  end
+
+  it "verifies observer responds to update" do
+    -> {
+      @observable.add_observer(@observable)
+    }.should.raise(NoMethodError)
+  end
+
+  it "receives the callback" do
+    @observer.value.should == nil
+    @observable.changed
+    @observable.notify_observers("test")
+    @observer.value.should == "test"
+  end
+
+end