Turn off transactional fixtures only for Capybara javascript specs

edit_post_spec.rb

# requests/edit_post_spec.rb

require 'spec_helper'

feature 'editing a post', js: true do
  let(:post) { create :post }
  let(:user) { post.creator }

  before { sign_in user }

  scenario 'creator attaches an image to a post' do
    # user attaches image and expects to see it after submit
  end
end

selenium_helper.rb

# support/selenium_helper.rb

module SeleniumHelper
  def self.included(base)
    base.class_eval do
      self.use_transactional_fixtures = false if metadata[:js]
    end
  end
end

spec_helper.rb

RSpec.configure do |config|
  config.use_transactional_fixtures = true
  config.include SeleniumHelper, :type => :request
  
  config.before(:suite) do
    DatabaseCleaner.strategy = :truncation
  end

  config.before(:each, js: true) do
    DatabaseCleaner.start
  end

  config.after(:each, js: true) do
    DatabaseCleaner.clean
  end
end