Test the index page with all locales to make sure missing frontend locale files aren't fatal

test/integration/locale_test.rb

@@ -0,0 +1,22 @@
+require 'test_helper'
+
+class LocaleTest < ActionDispatch::IntegrationTest
+
+  fixtures :users
+
+  def test_locale_index
+    logs_in_as(users(:other_user_email), 'open')
+    @user = User.find(@request.session['user_id'])
+    locales = I18n.available_locales.map {|l| l.to_s}
+    locales.each do |locale|
+      # Set the locale
+      @user.preference.locale = locale
+      @user.preference.save!
+      logs_in_as(users(:other_user_email), 'open')
+      get '/'
+      assert_response :success
+      assert_template "todos/index"
+    end
+  end
+
+end