Add integration tests with capybara (#1707)

* Add integration tests with capybara
* Add Rake task for running integration tests
* Don't include integration in default test task

Gemfile

@@ -18,6 +18,11 @@ gem 'warbler', platforms: :jruby
 # current CI workflows pass, we should only try to install this version of
 # Nokogiri for newer Ruby versions.
 
+group :test do
+  gem 'selenium-webdriver', require: false
+  gem 'capybara', require: false
+end
+
 gemspec
 
 gem 'rake', '~> 13.0'

Rakefile

@@ -72,9 +72,21 @@ end
 task :default => :test
 
 require 'rake/testtask'
+
+namespace :test do
+  Rake::TestTask.new('capybara') do |test|
+    test.libs << 'lib' << 'test' << '.'
+    test.pattern = 'test/integration/**/test_*.rb'
+    test.verbose = true
+    test.warning = false
+  end
+end
+
 Rake::TestTask.new(:test) do |test|
   test.libs << 'lib' << 'test' << '.'
-  test.pattern = 'test/**/test_*.rb'
+  test.test_files = FileList.new('test/**/test_*.rb') do |fl|
+    fl.exclude('test/integration/**/test_*.rb')
+  end
   test.verbose = true
   test.warning = false
 end

test/helper.rb

@@ -32,6 +32,8 @@ ENV['RACK_ENV'] = 'test'
 require 'gollum'
 require 'gollum/app'
 
+CAPYBARA_DRIVER = ENV['CI'] ? :selenium_chrome_headless : ENV.fetch('CAPYBARA_DRIVER', :selenium_chrome).to_sym
+
 # Disable the metadata feature
 $METADATA = false
 

test/integration/test_js_errors.rb

@@ -0,0 +1,49 @@
+require File.expand_path(File.join(File.dirname(__FILE__), '..', 'helper'))
+require 'selenium-webdriver'
+require 'capybara/dsl'
+
+Capybara.default_driver = ::CAPYBARA_DRIVER
+Capybara.server = :webrick
+
+def console_log(page, level = :severe)
+  page.driver.browser.logs.get(:browser).select{|log| log.level == level.to_s.upcase }
+end
+
+def expected_errors
+  Regexp.union([
+    %r{Refused to apply style from 'http:.*/gollum/create/custom.css'}
+  ])
+end
+
+def assert_only_expected_errors(log)
+  assert_equal [], log.reject {|err| err.message.match?(expected_errors) }
+end
+
+context 'Frontend with mathjax' do
+  include Capybara::DSL
+  
+  setup do
+    @path = cloned_testpath("examples/lotr.git")
+    @wiki = Gollum::Wiki.new(@path)
+    Precious::App.set(:gollum_path, @path)
+    Precious::App.set(:wiki_options, {mathjax: true})
+    Capybara.app = Precious::App
+  end
+  
+  test 'no unexpected errors on /' do
+    visit '/'
+    log = console_log(page)
+    assert_only_expected_errors(log)
+  end
+  
+  test 'no unexpected errors on /create/' do
+    visit '/create/Foobar'
+    log = console_log(page)
+    assert_only_expected_errors(log)
+  end
+  
+  teardown do
+    Capybara.reset_sessions!
+    Capybara.use_default_driver
+  end
+end