Generate some static site pages after JavaScript has run using Capybara

.travis.yml

@@ -9,7 +9,7 @@ addons:
     - cmake
 script:
   - xvfb-run bundle exec rake
-  - travis_wait 30 scripts/release.sh
+  - travis_wait 30 xvfb-run scripts/release.sh
   - bash <(curl -fsSL https://github.com/everypolitician/ensure-regression-tests/raw/master/ensure-regression-tests)
 sudo: false
 rvm:

Gemfile

@@ -28,15 +28,18 @@ end
 
 group :test do
   gem 'bundler-audit'
-  gem 'capybara'
-  gem 'capybara-webkit'
   gem 'html_validation'
   gem 'minitest'
   gem 'pry'
   gem 'rack-test'
   gem 'webmock'
 end
 
+group :test, :development do
+  gem 'capybara'
+  gem 'capybara-webkit'
+end
+
 group :quality do
   gem 'flog'
   gem 'reek'

Rakefile

@@ -57,4 +57,21 @@ end
 require 'bundler/audit/task'
 Bundler::Audit::Task.new
 
+require_relative 'lib/static_site/browser.rb'
+require 'uri'
+require 'pathname'
+desc 'Build static site pages that rely on JavaScript'
+task :generate_static_site_javascript_pages, [:base_url] do |_, args|
+  base_url = args.fetch(:base_url, 'http://localhost:4567')
+  pages_to_scrape = ["#{base_url}/needed.html"].map { |u| URI.parse(u) }
+  browser = StaticSite::Browser.new
+
+  pages_to_scrape.each do |url|
+    browser.visit(url)
+    file = Pathname.new(url.path[1..-1]).sub_ext('.html')
+    file.dirname.mkpath
+    file.write(browser.body_after_jquery_ajax)
+  end
+end
+
 task default: ['test', 'rubocop', 'bundle:audit']

lib/static_site/browser.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require 'capybara-webkit'
+
+module StaticSite
+  class Browser < Capybara::Webkit::Browser
+    JQUERY_WAIT_TIME = 2
+
+    def initialize
+      super(Capybara::Webkit::Connection.new(server: Capybara::Webkit::Server.new))
+      allow_unknown_urls
+    end
+
+    def body_after_jquery_ajax
+      wait_for_jquery_ajax
+      restore_pre_js_page_classes
+      body
+    end
+
+    def wait_for_jquery_ajax
+      Timeout.timeout(JQUERY_WAIT_TIME) do
+        # Errors if jQuery isn't on the page - should we check for that?
+        loop until evaluate_script('jQuery.active').zero?
+      end
+    end
+
+    # Restores page classes modified by running JS on the page
+    def restore_pre_js_page_classes
+      execute_script("$('html').addClass('no-js')")
+      execute_script("$('html').removeClass('flexwrap')")
+    end
+  end
+end

scripts/release.sh

@@ -13,8 +13,11 @@ set -eo pipefail
 build_viewer_static() {
   bundle exec ruby app.rb &
   while ! nc -z localhost 4567; do sleep 1; done
+  REPO_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )/../" && pwd )"
   cd /tmp
   wget -nv -m localhost:4567/status/all_countries.html || (echo "wget exited with non-zero exit code: $?" >&2 && exit 1)
+  cd localhost:4567
+  BUNDLE_GEMFILE=$REPO_DIR/Gemfile bundle exec rake -f $REPO_DIR/Rakefile generate_static_site_javascript_pages
 }
 
 deploy_viewer_static() {