Extract capybara config and improve headless_chrome driver config (#28681)

spec/rails_helper.rb

@@ -108,8 +108,6 @@ RSpec.configure do |config|
   end
 
   config.around :each, type: :system do |example|
-    driven_by :selenium, using: :headless_chrome, screen_size: [1600, 1200]
-
     # The streaming server needs access to the database
     # but with use_transactional_tests every transaction
     # is rolled-back, so the streaming server never sees the data

spec/support/capybara.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+Capybara.server_host = 'localhost'
+Capybara.server_port = 3000
+Capybara.app_host = "http://#{Capybara.server_host}:#{Capybara.server_port}"
+
+require 'selenium/webdriver'
+
+Capybara.register_driver :chrome do |app|
+  Capybara::Selenium::Driver.new(app, browser: :chrome)
+end
+
+Capybara.register_driver :headless_chrome do |app|
+  options = Selenium::WebDriver::Chrome::Options.new
+  options.add_argument '--headless=new'
+  options.add_argument '--window-size=1680,1050'
+
+  Capybara::Selenium::Driver.new(
+    app,
+    browser: :chrome,
+    options: options
+  )
+end
+
+Capybara.javascript_driver = :headless_chrome
+
+RSpec.configure do |config|
+  config.before(:each, type: :system) do
+    driven_by Capybara.javascript_driver
+  end
+end