I’m not so familiar with Rails system testing, but recently we started to write system tests in our app. We do write model tests and controller tests which cover most of the business logic. Our app started growing a lot, and we found in some pages there were silly mistakes we had in our app which were related to JavaScript/Ajax, and which indirectly affected some of our users.

Then our team decided to write down system tests for the pages where we use JavaScript/Ajax a lot.

We followed the Rails documentation for system testing and added all required setup for it. We added simple system tests for those pages, and it helped to trace JavaScript related issues. Bingo!

As we use Turbolinks in our Rails app which intercepts all clicks on <a href> links to the same domain, i.e., it converts every link into an Ajax request, but this caused some serious issues in our system tests.

Those issues were:

  1. System tests didn’t wait for Ajax request, so our post Ajax assertions were failing.
  2. Sometimes we did get this error Timeout::Error: execution expired.
  3. We were getting Net::ReadTimeout issues intermittently.
  4. Initial system test was taking too much time to run when Rails starts the server (In our case Puma).

For the 1st issue, We have followed this excellent blog post which helped us to resolve post Ajax assertions checking. We also have modified our flow for system testing, we have created a separate private method for user sign in. Our main sign-in page uses Ajax request in the background because of the Turbolinks. We created a method called user_sign_in, and we call it before every system test where current user context is required.

  def setup
    @john = users(:john)

  def teardown
    sign_out @john

  def test_some_system_test


    def user_sign_in
      visit root_url # sign in url
      assert_selector("div", text: "Log-in to your account")

      fill_in("user[email]", with: @john.email)
      fill_in("user[password]", with: "welcome1")

      click_on "Sign in"


In the user_sign_in method, we have called wait_for_ajax helper method. This method we have defined in the file called test/support/wait_for_ajax.rb. For more info about this wait_for_ajax method, please follow this blog post.

  module WaitForAjax

    def wait_for_ajax
      Timeout.timeout(Capybara.default_max_wait_time) do
        loop until finished_all_ajax_requests?

    def finished_all_ajax_requests?


Include this file in test/application_system_test_case.rb file and then you are done. This flow also fixed our 2nd issue.

For the 3rd and 4th issue, I have added this gem minitest-retry in Gemfile and called this gem in test/application_system_test_case.rb file.

require "test_helper"
require "selenium/webdriver"
require 'minitest/retry'

class ApplicationSystemTestCase < ActionDispatch::SystemTestCase

  include Devise::Test::IntegrationHelpers
  include WaitForAjax

  driven_by :selenium, using: :chrome, screen_size: [1200, 800]

By adding all these changes. Our system tests are running fine without any issues. System tests speed also got improved.

Please let me know if you have good ideas for these fixes. It would be helpful for our project as well as for Rails communities.

Happy Hacking :)