From e65457f36b60b5e8670b865094886b156703d688 Mon Sep 17 00:00:00 2001
From: Renaud Chaput <renchap@gmail.com>
Date: Tue, 27 Feb 2018 14:38:25 +0100
Subject: [PATCH] Switch browser-based tests to headless chrome

---
 .circleci/config.yml                          |  2 +-
 CHANGELOG.md                                  |  4 ++
 Gemfile.lock                                  | 14 +++---
 .../renderer_with_two_packs_test.rb           |  8 +--
 test/test_helper.rb                           | 50 ++++++++++++++++++-
 webpacker-react.gemspec                       |  2 +-
 6 files changed, 64 insertions(+), 16 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index b2cf4fc..4a0557f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -3,7 +3,7 @@ jobs:
   build:
     working_directory: ~/webpacker-react
     docker:
-      - image: circleci/ruby:2.4.3-node
+      - image: circleci/ruby:2.4.3-node-browsers
         environment:
           RAILS_ENV: test
     steps:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 37d8618..5b34ba2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Updated
 - Instructions for setting up `webpacker-react` with a modern Webpacker version
 
+### Changed
+- Tests now uses headless chrome instead of Poltergeist
+- Babel is configured with `babel-preset-env`
+
 ### Removed
 - Support for `react-hot-loader`. Please look at the README for instructions on how to use `react-hot-loader` 4 with your app, it is much simpler and better!
 
diff --git a/Gemfile.lock b/Gemfile.lock
index dd34f35..4e2d0ad 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -56,10 +56,12 @@ GEM
       rack (>= 1.0.0)
       rack-test (>= 0.5.4)
       xpath (>= 2.0, < 4.0)
-    cliver (0.3.2)
+    childprocess (0.8.0)
+      ffi (~> 1.0, >= 1.0.11)
     concurrent-ruby (1.0.5)
     crass (1.0.3)
     erubi (1.7.0)
+    ffi (1.9.23)
     globalid (0.4.1)
       activesupport (>= 4.2.0)
     i18n (0.9.5)
@@ -80,10 +82,6 @@ GEM
     parallel (1.12.1)
     parser (2.5.0.2)
       ast (~> 2.4.0)
-    poltergeist (1.17.0)
-      capybara (~> 2.1)
-      cliver (~> 0.3.1)
-      websocket-driver (>= 0.2.0)
     powerpack (0.1.1)
     public_suffix (3.0.2)
     rack (2.0.4)
@@ -122,6 +120,10 @@ GEM
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
     ruby-progressbar (1.9.0)
+    rubyzip (1.2.1)
+    selenium-webdriver (3.9.0)
+      childprocess (~> 0.5)
+      rubyzip (~> 1.2)
     sprockets (3.7.1)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -151,10 +153,10 @@ DEPENDENCIES
   bundler (~> 1.13)
   capybara
   minitest (~> 5.0)
-  poltergeist
   rails (~> 5.1.1)
   rake (~> 10.0)
   rubocop (>= 0.47)
+  selenium-webdriver
   webpacker (~> 2.0.0)
   webpacker-react!
 
diff --git a/test/integration/renderer_with_two_packs_test.rb b/test/integration/renderer_with_two_packs_test.rb
index 4c90052..e9b2f9f 100644
--- a/test/integration/renderer_with_two_packs_test.rb
+++ b/test/integration/renderer_with_two_packs_test.rb
@@ -5,12 +5,8 @@ class RendererWithTwoPacksTest < ActionDispatch::IntegrationTest
   test "component mounts" do
     require_js
 
-    begin
-      visit "/two_packs/view_all"
-    rescue Capybara::Poltergeist::JavascriptError => error
-      assert error.message =~ /Following components are already registered: HelloReact/
-    end
-
+    visit "/two_packs/view_all"
+    assert_js_error /Following components are already registered: HelloReact/
     assert page.has_content? "Hello, I am a component rendered from a view!"
     assert page.has_content? "Component A"
     assert page.has_content? "Component B"
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 720f5e6..aadef7b 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -5,17 +5,63 @@
 require "minitest/autorun"
 require "capybara/rails"
 
+require "selenium/webdriver"
+
+Capybara.register_driver :headless_chrome do |app|
+  capabilities = Selenium::WebDriver::Remote::Capabilities.chrome(
+    chromeOptions: { args: %w(headless disable-gpu) }
+  )
+
+  Capybara::Selenium::Driver.new app,
+    browser: :chrome,
+    desired_capabilities: capabilities
+end
+
+Capybara.javascript_driver = :headless_chrome
+
 class ActionDispatch::IntegrationTest
+  class DriverJSError < StandardError; end
   include Capybara::DSL
-  require "capybara/poltergeist"
 
-  Capybara.javascript_driver = :poltergeist
+  def setup
+    @ignored_js_errors = []
+  end
 
   def teardown
+    if Capybara.current_driver == :headless_chrome
+      errors = current_js_errors.select do |message|
+        # If the message matches any ones ignored, skip it
+        puts "==="
+        puts @ignored_js_errors.inspect
+        puts message
+        !@ignored_js_errors.any? { |e| !(message =~ e) }
+      end
+
+      assert errors.empty?, "Got JS errors: \n#{errors.join("\n\n")}"
+    end
+
     Capybara.current_driver = nil
   end
 
   def require_js
     Capybara.current_driver = Capybara.javascript_driver
   end
+
+  def current_js_errors
+    page.driver.browser.manage.logs.get(:browser)
+      .select { |e| e.level == "SEVERE" && message.present? }
+      .map(&:message)
+      .to_a
+  end
+
+  def assert_js_error(error_match)
+    error = current_js_errors.find { |e| e. =~ error_match }
+
+    if error
+      @ignored_js_errors << error
+    else
+      puts error.to_s
+      assert false, "Expected a JS error matching: #{error_match.to_s}"
+    end
+  end
 end
diff --git a/webpacker-react.gemspec b/webpacker-react.gemspec
index 722d4a4..b0b97c1 100644
--- a/webpacker-react.gemspec
+++ b/webpacker-react.gemspec
@@ -28,5 +28,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "minitest", "~> 5.0"
   spec.add_development_dependency "capybara"
-  spec.add_development_dependency "poltergeist"
+  spec.add_development_dependency "selenium-webdriver"
 end