Gems

group :development do
  gem "guard", require: false
  gem "guard-livereload", require: false
  gem "rack-livereload"
end

Guardfile

# require "em/pure_ruby"

# A sample Guardfile
# More info at https://github.com/guard/guard#readme

## Uncomment and set this to only include directories you want to watch
# directories %w(app lib config test spec features) \
#  .select{|d| Dir.exists?(d) ? d : UI.warning("Directory #{d} does not exist")}

## Note: if you are using the `directories` clause above and you are not
## watching the project directory ('.'), then you will want to move
## the Guardfile to a watched dir and symlink it back, e.g.
#
#  $ mkdir config
#  $ mv Guardfile config/
#  $ ln -s config/Guardfile .
#
# and, you'll have to watch "config/Guardfile" instead of "Guardfile"

guard "livereload" do
  extensions = {
    css: :css,
    scss: :css,
    sass: :css,
    png: :png,
    gif: :gif,
    jpg: :jpg,
    jpeg: :jpeg,
    erb: :erb
  }

  rails_view_exts = %w[erb]

  # file types LiveReload may optimize refresh for
  compiled_exts = extensions.values.uniq
  watch(%r{public/.+\.(#{compiled_exts * '|'})})

  extensions.each do |ext, type|
    watch(%r{
          (?:app|lib|vendor)
          (?:/assets/\w+/(?<path>[^.]+) # path+base without extension
           (?<ext>\.#{ext})) # matching extension (must be first encountered)
          (?:\.\w+|$) # other extensions
          }x) do |m|
      path = m[1]
      "/assets/#{path}.#{type}"
    end
  end

  # file needing a full reload of the page anyway
  watch(%r{app/views/.+\.(#{rails_view_exts * '|'})$})
  watch(%r{app/helpers/.+\.rb})
  # watch(%r{config/locales/.+\.yml})
end