Spot some common mistakes in multi-language rails translations files.

spot.rb

require 'yaml'

# {a,{b,{c}} => [a, a.b, a.b.c]
def parse_keys(hash, keys = [], prefix = nil)
  hash.each do |k, v|
    key = [prefix, k].compact.join('.')

    if v.is_a?(Hash)
      parse_keys(v, keys, key)
    else
      keys << key
    end
  end

  keys
end

# spots only simple uses: t("a.b"), {{t "a.b"}}
def used?(key)
  greps = [
    %|git grep -Fq 'Translation="#{key}"'|,
    %|git grep -Fq "Translation='#{key}'"|,
    %|git grep -Fq '{{t "#{key}"'|,
    %|git grep -Fq "{{t '#{key}'"|,
    %|git grep -Fq 't("#{key}"'|,
    %|git grep -Fq "t('#{key}'"|
  ]

  greps.any? { |cmd| system(cmd) }
end

locales = {}

Dir.glob('config/locales/*.yml').each do |file|
  yaml = YAML.load(File.read(file))
  locale = yaml.first.first
  locales[locale] = parse_keys(yaml[locale])
end

locales.each do |locale,keys|
  other_locales = locales.reject { |k,_| k == locale }

  keys.each do |key|
    other_locales.each do |other_local,other_keys|
      unless other_keys.include?(key)
        $stderr.puts "[error]: #{locale}.#{key} not present in #{other_locale}"
      end
    end
  end
end

locales.values.flatten.uniq.each do |key|
  unless used?(key)
    $stderr.puts "[warning]: #{key}: does not appear to be used"
  end
end