Add spec for Fluentd::Agent::LocalCommon#pid

spec/models/fluentd/agent/local_common_spec.rb

@@ -0,0 +1,29 @@
+require 'spec_helper'
+require 'fileutils'
+
+describe 'Fluentd::Agent::LocalCommon' do
+  subject { target_class.new.tap{|t| t.pid_file = pid_file_path} }
+
+  let!(:target_class) { Struct.new(:pid_file){ include Fluentd::Agent::LocalCommon } }
+  let!(:pid_file_path) { Rails.root.join('tmp', 'fluentd-test', 'local_common_test.pid').to_s }
+
+  describe '#pid' do
+    context 'no pid file exists' do
+      its(:pid) { should be_nil }
+    end
+
+    context 'empty pid file given' do
+      before { FileUtils.touch pid_file_path }
+      after  { FileUtils.rm pid_file_path }
+
+      its(:pid) { should be_nil }
+    end
+
+    context 'valid pid file given' do
+      before { File.write pid_file_path, '99999' }
+      after  { FileUtils.rm pid_file_path }
+
+      its(:pid) { should eq(99999) }
+    end
+  end
+end