This gist is a part of a Rakefile I use to test my Puppet's ERB (templates) files.

puppet_rakefile_test_erb_templates.rb

# This gist is a part of a Rakefile I use to test my Puppet's ERB (templates) files.
# Add this to the Rakefile at the root of your puppet module.
#
# == Examples:
#   rake test:erb
# or
#   rake test
#
# Author:: Joseph Herlant ([email protected])
# Copyright:: Copyright (c) 2014 Joseph Herlant
# License:: Distributed under the terms of the Apache 2 license
#

# This is just to have a nice colored output
class String
  def red;            "\033[31m#{self}\033[0m" end
  def green;          "\033[32m#{self}\033[0m" end
end

desc "Run erb syntax checks."
task :test => [
  'test:erb',
]

namespace :test do
  desc 'Checks that erb files can be rendered by the erb parser.'
  task :erb do
    require 'erb'

    successes = []
    failures = []
    Dir.glob("**/*.erb").each do |t_file|
      puts "Checking syntax for #{t_file}"

      # Run syntax checker in subprocess.
      system("erb -P -x -T '-' #{t_file} | ruby -c > /dev/null")
      # Keep track of the results.
      if $?.success?
        successes << t_file
      else
        failures << t_file
      end
    end
    # Print the results.
    total_t = successes.count + failures.count
    puts "#{successes.count} templates syntax valid over #{total_t}.".green
    if failures.count > 0
      puts "#{failures.count} files failed:".red
      puts
      failures.each{ |filename| puts filename.red }
      fail("#{failures.count} files failed syntax check.")
    else
      puts "#{failures.count} failed templates syntax check.".green
    end
    puts
  end
end