Rails helper so that "?_locale_keys=1" in URL shows locale keys

application_controller.rb

class ApplicationController < ActionController::Base
  include I18nHelper
end

i18n_helper.rb

# frozen_string_literal: true

module I18nHelper
  # Print out the keys if you add ?_locale_keys=1 in params
  def t(key, options = {})
    key = scope_key_by_partial(key) if respond_to?(:scope_key_by_partial)

    # Make sure params isn't triggered in Mailers by looking for request
    if (respond_to?(:request) && request && params[:_locale_keys]) || \
       (@mail_params && @mail_params[:_locale_keys])
      if options.any?
        "#{key} (#{options.map { |k, v| "#{k}: #{v.inspect}" }.join(',')})"
      else
        key
      end
    else
      translate_with_default_scope(key, conf.site, options)
    end
  end

  private

  def translate_with_default_scope(key, scope, options = {})
    default_lookup = proc { I18n.translate(key, options) }
    I18n.translate(key, options.merge(scope: scope, default: default_lookup))
  end
end