Loading I18n translation files outside of Rails (for example, as part of an isolated/non-Rails spec)

i18n_helpers.rb

# frozen_string_literal: true

module I18nHelpers
  def self.included(_mod)
    locale_dir = Pathname.new(__dir__) + '../../config/locales/'
    [:en].each do |locale|
      locale_file = locale_dir + "#{locale}.yml"
      I18n.backend.store_translations(locale, YAML.load_file(locale_file.open)[String(locale)])
    end
  end
end

# spec/widget_spec.rb
require 'app/widget'

RSpec.describe Widget do
  include 'i18n_helpers'
  
  # ✨ I18n :en translation is now loaded!
  
end