I’ve recently started acceptance testing my JavaScript, and it has been something of a rough ride. Using Capybara/RSpec with the poltergeist JS driver, I kept encountering seemingly random failures which nearly forced me to give up on acceptance testing my JS at all. In the end, I managed to work around the issues:

With the help of an excellent post by Avdi Grimm, I installed database_cleaner and configured it to work in the Capybara/poltergeist environment. However, this led to issues where tests didn’t seem to be properly cleaning up after themselves.

Thanks to this reply I tracked down the problem to a bug in RSpec 2.13. If you are going to use database_cleaner with Capybara/poltergeist, make sure you are using RSpec >= 2.14.0.rc1. For my Rails app, this is what I put in my Gemfile:

gem 'rspec-rails', "~> 2.14.0.rc1"

At this point, I thought I had the problem solved.

And yet, there was more nondeterminism to come

Tests were still failing with ActiveRecord not found exceptions. Less frequently, but still enough to ruin the utility of my test suite. After much trial and error, I added a single line to the database_cleaner config in the reply above, and it appears to actually work. Here’s my database_cleaner.rb:

RSpec.configure do |config|
  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.strategy = Capybara.current_driver == :rack_test ? :transaction : :truncation
    DatabaseCleaner.clean
    DatabaseCleaner.start
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end
end

Hopefully this helps some folks looking to use Capybara to test their JavaScript