specs: save a screenshot of failing integration tests

Gemfile

@@ -124,19 +124,23 @@ gem "administrate"
 gem 'rack-mini-profiler'
 
 group :test do
-  gem 'capybara'
   gem 'launchy'
   gem 'factory_bot'
   gem 'database_cleaner'
   gem 'webmock'
   gem 'shoulda-matchers', require: false
-  gem 'capybara-selenium'
   gem 'timecop'
   gem 'guard'
   gem 'guard-rspec', require: false
   gem 'guard-livereload', require: false
   gem 'vcr'
   gem 'rails-controller-testing'
+
+  # Integration testing
+  gem 'capybara'
+  gem 'capybara-selenium'
+  # Save a dump of the page when an integration test fails
+  gem 'capybara-screenshot'
 end
 
 group :development do

Gemfile.lock

@@ -118,6 +118,9 @@ GEM
       rack (>= 1.0.0)
       rack-test (>= 0.5.4)
       xpath (>= 2.0, < 4.0)
+    capybara-screenshot (1.0.21)
+      capybara (>= 1.0, < 4)
+      launchy
     capybara-selenium (0.0.6)
       capybara
       selenium-webdriver
@@ -798,6 +801,7 @@ DEPENDENCIES
   browser
   byebug
   capybara
+  capybara-screenshot
   capybara-selenium
   carrierwave
   carrierwave-i18n

spec/spec_helper.rb

@@ -22,6 +22,7 @@ ENV['RAILS_ENV'] ||= 'test'
 require File.expand_path('../config/environment', __dir__)
 require 'rspec/rails'
 require 'capybara/rspec'
+require 'capybara-screenshot/rspec'
 require 'database_cleaner'
 require 'webmock/rspec'
 require 'shoulda-matchers'
@@ -50,6 +51,15 @@ ActiveSupport::Deprecation.silenced = true
 
 Capybara.default_max_wait_time = 1
 
+# Save a snapshot of the HTML page when an integration test fails
+Capybara::Screenshot.autosave_on_failure = true
+# Keep only the screenshots generated from the last failing test suite
+Capybara::Screenshot.prune_strategy = :keep_last_run
+# Tell Capybara::Screenshot how to take screenshots when using the headless_chrome driver
+Capybara::Screenshot.register_driver :headless_chrome do |driver, path|
+  driver.browser.save_screenshot(path)
+end
+
 # Requires supporting ruby files with custom matchers and macros, etc,
 # in spec/support/ and its subdirectories.
 Dir[Rails.root.join('spec', 'support', '**', '*.rb')].each { |f| require f }