capybara-webkit/spec/support/app_runner.rb

# Boots a single Capybara::Server for a Rack application that delegates to another, singleton Rack
# application that can be configured for each spec. Also configures Capybara to use that server.

require 'sinatra/base'

module AppRunner
  class << self
    attr_accessor :app, :app_host
  end

  def self.boot
    app_container = lambda { |env| AppRunner.app.call(env) }
    server = Capybara::Server.new(app_container)
    server.boot
    self.app_host = "http://127.0.0.1:#{server.port}"
  end

  def self.reset
    self.app = lambda do |env|
      [200, { 'Content-Type' => 'html', 'Content-Length' => 0 }, []]
    end
  end

  def run_application(app)
    AppRunner.app = app
  end

  def driver_for_app(&body)
    app = Class.new(ExampleApp, &body)
    run_application app
    build_driver
  end

  def driver_for_html(html)
    run_application_for_html html
    build_driver
  end

  def run_application_for_html(html)
    run_application lambda { |env|
      [200, { 'Content-Type' => 'text/html', 'Content-Length' => html.size.to_s }, [html]]
    }
  end

  private

  def build_driver
    Capybara::Webkit::Driver.new(AppRunner.app, :browser => $webkit_browser)
  end

  def self.included(example_group)
    example_group.class_eval do
      before { AppRunner.reset }

      around do |example|
        Capybara.run_server = false
        Capybara.app_host = AppRunner.app_host
        begin
          example.run
        ensure
          Capybara.run_server = true
          Capybara.app_host = nil
        end
      end
    end
  end
end

class ExampleApp < Sinatra::Base
  # Sinatra fixes invalid responses that would break QWebPage, so this middleware breaks them again
  # for testing purposes.
  class ResponseInvalidator
    def initialize(app)
      @app = app
    end

    def call(env)
      response = @app.call(env)
      if response.to_a[1]['X-Response-Invalid']
        [404, {}, []]
      else
        response
      end
    end
  end

  use ResponseInvalidator

  def invalid_response
    [200, { 'X-Response-Invalid' => 'TRUE' }, []]
  end
end

AppRunner.boot