Add the outline of an observer by way of the heartbeat observer

.rspec

@@ -1 +1 @@
---order random --fail-fast --format doc
+--order random --fail-fast --format doc --color

lib/blick/agent/observers/heartbeat.rb

@@ -0,0 +1,46 @@
+require 'blick/events'
+
+module Blick
+  module Agent
+    module Observers
+      class Heartbeat
+        #######################################################################
+        ### Observer registry/internals
+        #######################################################################
+        def self.name
+          'Blick Internal Heartbeat'
+        end
+
+        def self.description
+          'An observer which emits periodic heartbeats'
+        end
+
+        def self.enabled
+          true
+        end
+
+        # @return [Fixnum] number of seconds to run this observer
+        def self.interval
+          60
+        end
+
+        def self.platforms
+          @platforms ||= [:all]
+        end
+
+        #######################################################################
+        ### Observer execution/runtime
+        #######################################################################
+
+        def prepare
+        end
+
+        def execute
+        end
+
+        def cleanup
+        end
+      end
+    end
+  end
+end

spec/agent/observers/heartbeat_spec.rb

@@ -0,0 +1,6 @@
+require 'spec_helper'
+require 'blick/agent/observers/heartbeat'
+
+describe Blick::Agent::Observers::Heartbeat do
+  it_behaves_like 'an Observer'
+end

spec/spec_helper.rb

@@ -1,6 +1,10 @@
 require 'rspec'
 
-$LOAD_PATH.unshift(File.expand_path(__FILE__) + '/../')
+$LOAD_PATH.unshift(File.expand_path(File.dirname(__FILE__) + '/../lib'))
+
+Dir[File.expand_path(File.dirname(__FILE__) + '/support/**/*.rb')].each do |f|
+  load f
+end
 
 RSpec.configure do |c|
 end

spec/support/observer_examples.rb

@@ -0,0 +1,37 @@
+
+shared_examples 'an Observer' do
+  context 'class methods' do
+    subject(:observer) { described_class }
+
+    describe '.name' do
+      subject { observer.name }
+      it { should be_instance_of String }
+    end
+
+    describe '.description' do
+      subject { observer.description }
+      it { should be_instance_of String }
+    end
+
+    describe '.interval' do
+      subject { observer.interval }
+
+      it { should be_instance_of Fixnum }
+      it { should be > 0 }
+    end
+
+    it { should respond_to :enabled }
+
+    describe '.platforms' do
+      subject { observer.platforms }
+      it { should be_instance_of Array }
+    end
+  end
+
+  context 'instance methods' do
+    let(:observer) { described_class.new }
+    it { should respond_to :prepare }
+    it { should respond_to :execute }
+    it { should respond_to :cleanup }
+  end
+end