encapsulate rails 3 check for easier testing

lib/whenever.rb

@@ -19,4 +19,8 @@ module Whenever
     Dir.pwd
   end
 
-end
+  def self.rails3?
+    File.exists?(File.join(path, 'script', 'rails'))
+  end
+
+end

lib/whenever/setup.rb

@@ -11,7 +11,7 @@ job_type :command, ":task :output"
 job_type :rake,    "cd :path && RAILS_ENV=:environment rake :task --silent :output"
 
 # Create a runner job that's appropriate for the Rails version,
-if File.exists?(File.join(path, 'script', 'rails'))
+if Whenever.rails3?
   job_type :runner, "cd :path && script/rails runner -e :environment ':task' :output"
 else
   job_type :runner, "cd :path && script/runner -e :environment ':task' :output"

test/functional/output_default_defined_jobs_test.rb

@@ -110,7 +110,7 @@ class OutputDefaultDefinedJobsTest < Test::Unit::TestCase
   context "A runner for a Rails 3 app" do
     setup do
       Whenever.expects(:path).at_least_once.returns('/my/path')
-      File.expects(:exists?).with('/my/path/script/rails').returns(true)
+      Whenever.expects(:rails3?).returns(true)
       @output = Whenever.cron \
       <<-file
         set :job_template, nil