Check JS Jammit Manifest for untracked files

pre-commit-jammit

# Check the jammit asset manifest for files that have not been tracked
# Only javascripts for now since we gitignore sass generated .css files
# TODO check for .css and .scss files
require 'rubygems'
require 'jammit'

j = Jammit.load_configuration(Jammit::DEFAULT_CONFIG_PATH)
files = j.configuration[:javascripts].values.flatten.uniq
errors = []
files.each do |f|
  errors.push f if `git ls-files #{f}`.empty?
end
if errors.length > 0
  puts 'Jammit doesn\'t have: ' << errors.join(", ")
  flag = true
end