Fix the new SerfWatcher and add a spec

lib/synapse/service_watcher/serf.rb

@@ -2,7 +2,7 @@
 
 require 'thread'
 
-module Synapse::ServiceWatcher
+class Synapse::ServiceWatcher
   class SerfWatcher < BaseWatcher
 
     def initialize(opts = {}, synapse)
@@ -13,7 +13,6 @@ def initialize(opts = {}, synapse)
         @all_backups_except_one = opts['haproxy']['all_backups_except_one']
       end
     end
-
     def start
       @serf_members = '/dev/shm/serf_members.json'
       @cycle_delay = 1

spec/lib/synapse/serf_spec.rb

@@ -0,0 +1,30 @@
+require 'spec_helper'
+require 'synapse/service_watcher/serf'
+
+describe Synapse::ServiceWatcher::SerfWatcher do
+  let(:mock_synapse) do
+    mock_synapse = instance_double(Synapse::Synapse)
+    mockgenerator = Synapse::ConfigGenerator::BaseGenerator.new()
+    allow(mock_synapse).to receive(:available_generators).and_return({
+      'haproxy' => mockgenerator
+    })
+    mock_synapse
+  end
+  let(:discovery) { { 'method' => 'serf', 'hosts' => 'somehost','path' => 'some/path' } }
+
+  let(:config) do
+    {
+      'name' => 'test',
+      'haproxy' => {},
+      'discovery'=> discovery
+    }
+  end
+
+  context 'SerfWatcher' do
+    subject { Synapse::ServiceWatcher::SerfWatcher.new(config, mock_synapse) }
+    it 'should validate' do
+      expect(subject.send(:validate_discovery_opts)).to be_nil
+    end
+  end
+end
+