Turn system testing into it's own gem and rename

Renames `Rails::SystemTestCase` to `ActionSystemTest` and moves it to a
gem under the Rails name.

We need to name the class `ActionSystemTestCase` because the gem expects
a module but tests themselves expect a class.

Adds MIT-LICENSE, CHANGELOG, and README for the future.

3 files changed, 226 insertions, 0 deletions

diff --git a/actionsystemtest/lib/action_system_test/driver_adapters/capybara_driver.rb b/actionsystemtest/lib/action_system_test/driver_adapters/capybara_driver.rb
new file mode 100644
index 0000000000..5362f6db25
--- /dev/null
+++ b/actionsystemtest/lib/action_system_test/driver_adapters/capybara_driver.rb
@@ -0,0 +1,83 @@
+require "action_system_test/driver_adapters/web_server"
+
+module ActionSystemTest
+  module DriverAdapters
+    # == CapybaraDriver for System Testing
+    #
+    # The <tt>CapybaraDriver</tt> is a shim that sits between Rails and
+    # Capybara.
+    #
+    # The drivers Capybara supports are: +:rack_test+, +:selenium+, +:webkit+,
+    # and +:poltergeist+.
+    #
+    # Rails provides its own defaults for Capybara with the Selenium driver
+    # through <tt>RailsSeleniumDriver</tt>, but allows users to use Selenium
+    # directly.
+    #
+    # To set your system tests to use one of Capybara's default drivers, add
+    # the following to yur Rails' configuration test environment:
+    #
+    #   config.system_testing.driver = :rack_test
+    #
+    # The +:rack_test+ driver is a basic test driver that doesn't support
+    # JavaScript testing and doesn't require a server.
+    #
+    # The +:poltergeist+ and +:webkit+ drivers are headless, but require some
+    # extra environment setup. Because the default server for Rails is Puma, each
+    # of the Capybara drivers will default to using Puma. Changing the configuration
+    # to use Webrick is possible by initalizing a new driver object.
+    #
+    # The default settings for the <tt>CapybaraDriver</tt> are:
+    #
+    #   #<ActionSystemTest::DriverAdapters::CapybaraDriver:0x007ff0e992c1d8
+    #     @name=:rack_test,
+    #     @server=:puma,
+    #     @port=28100
+    #    >
+    #
+    # The settings for the <tt>CapybaraDriver</tt> can be changed from
+    # Rails' configuration file.
+    #
+    #   config.system_testing.driver = ActionSystemTest::DriverAdapters::CapybaraDriver.new(
+    #     name: :webkit,
+    #     server: :webrick
+    #   )
+    class CapybaraDriver
+      include WebServer
+
+      CAPYBARA_DEFAULTS = [ :rack_test, :selenium, :webkit, :poltergeist ]
+
+      attr_reader :name, :server, :port
+
+      def initialize(name: :rack_test, server: :puma, port: 28100)
+        @name = name
+        @server = server
+        @port = port
+      end
+
+      def call
+        registration
+        setup
+      end
+
+      def supports_screenshots?
+        @name != :rack_test
+      end
+
+      private
+        def registration
+          register_server
+        end
+
+        def setup
+          set_server
+          set_port
+          set_driver
+        end
+
+        def set_driver
+          Capybara.default_driver = @name
+        end
+    end
+  end
+end
diff --git a/actionsystemtest/lib/action_system_test/driver_adapters/rails_selenium_driver.rb b/actionsystemtest/lib/action_system_test/driver_adapters/rails_selenium_driver.rb
new file mode 100644
index 0000000000..16e485398a
--- /dev/null
+++ b/actionsystemtest/lib/action_system_test/driver_adapters/rails_selenium_driver.rb
@@ -0,0 +1,98 @@
+require "action_system_test/driver_adapters/web_server"
+
+module ActionSystemTest
+  module DriverAdapters
+    # == RailsSeleniumDriver for System Testing
+    #
+    # The <tt>RailsSeleniumDriver</tt> uses the Selenium 2.0 webdriver. The
+    # selenium-webdriver gem is required by this driver.
+    #
+    # The <tt>RailsSeleniumDriver</tt> is useful for real browser testing and
+    # supports Chrome and Firefox.
+    #
+    # By default Rails system testing will use Rails' configuration with Capybara
+    # and the Selenium driver. To explictly set the <tt>RailsSeleniumDriver</tt>
+    # add the following to your Rails' configuration test environment:
+    #
+    #   config.system_testing.driver = :rails_selenium_driver
+    #
+    # Because this driver supports real browser testing it is required that a
+    # server is configured.
+    #
+    # If no server is specified when the driver is initialized, Puma will be used
+    # by default. The default settings for the <tt>RailsSeleniumDriver</tt>
+    # are as follows:
+    #
+    #   #<ActionSystemTest::DriverAdapters::RailsSeleniumDriver:0x007ff0e992c1d8
+    #     @browser=:chrome,
+    #     @server=:puma,
+    #     @port=28100,
+    #     @screen_size=[ 1400, 1400 ]
+    #    >
+    #
+    # The settings for the <tt>RailsSeleniumDriver</tt> can be changed in the
+    # Rails configuration file.
+    #
+    #   config.system_testing.driver = ActionSystemTest::DriverAdapters::RailsSeleniumDriver.new(
+    #     server: :webrick,
+    #     port: 28100,
+    #     screen_size: [ 800, 800 ]
+    #   )
+    #
+    # The default browser is set to Chrome because the current version of
+    # Firefox does not work with selenium-webdriver. If you want to use Firefox,
+    # you will need to use Firefox 45.0esr or 47.0 and ensure
+    # that selenium-webdriver is version 2.53.4. To change the browser from
+    # +:chrome+ to +:firefox+, initialize the Selenium driver in your Rails'
+    # test environment:
+    #
+    #   config.system_testing.driver = ActionSystemTest::DriverAdapters::RailsSeleniumDriver.new(
+    #     browser: :firefox
+    #   )
+    class RailsSeleniumDriver
+      include WebServer
+
+      attr_reader :browser, :server, :port, :screen_size
+
+      def initialize(browser: :chrome, server: :puma, port: 28100, screen_size: [ 1400, 1400 ]) # :nodoc:
+        @browser     = browser
+        @server      = server
+        @port        = port
+        @screen_size = screen_size
+      end
+
+      def call # :nodoc:
+        registration
+        setup
+      end
+
+      def supports_screenshots?
+        true
+      end
+
+      private
+        def registration
+          register_browser_driver
+          register_server
+        end
+
+        def setup
+          set_server
+          set_port
+          set_driver
+        end
+
+        def register_browser_driver
+          Capybara.register_driver @browser do |app|
+            Capybara::Selenium::Driver.new(app, browser: @browser).tap do |driver|
+              driver.browser.manage.window.size = Selenium::WebDriver::Dimension.new(*@screen_size)
+            end
+          end
+        end
+
+        def set_driver
+          Capybara.default_driver = @browser.to_sym
+        end
+    end
+  end
+end
diff --git a/actionsystemtest/lib/action_system_test/driver_adapters/web_server.rb b/actionsystemtest/lib/action_system_test/driver_adapters/web_server.rb
new file mode 100644
index 0000000000..e115fe583c
--- /dev/null
+++ b/actionsystemtest/lib/action_system_test/driver_adapters/web_server.rb
@@ -0,0 +1,45 @@
+begin
+  require "rack/handler/puma"
+rescue LoadError
+  false
+end
+
+module ActionSystemTest
+  module DriverAdapters
+    module WebServer # :nodoc:
+      def register_server
+        Capybara.register_server @server do |app, port, host|
+          case @server
+          when :puma
+            register_puma(app, port)
+          when :webrick
+            register_webrick(app, port)
+          else
+            register_default(app, port)
+          end
+        end
+      end
+
+      private
+        def register_default(app, port)
+          Capybara.run_default_server(app, port)
+        end
+
+        def register_puma(app, port)
+          Rack::Handler::Puma.run(app, Port: port, Threads: "0:4")
+        end
+
+        def register_webrick(app, port)
+          Rack::Handler::WEBrick.run(app, Port: port)
+        end
+
+        def set_server
+          Capybara.server = @server
+        end
+
+        def set_port
+          Capybara.server_port = @port
+        end
+    end
+  end
+end