Let PhantomJS load local images

This change fix a memory leak due to a Webkit bug:
https://github.com/ariya/phantomjs/issues/12903

Also:

- Whitelist only localhost and 127.0.0.1 in Capybara + JS specs
- Blacklist all requests to media such as images, videos, PDFs, CSVs etc.
- Log all the requests made.

Signed-off-by: Rémy Coutable <remy@rymai.me>

features/support/capybara.rb

@@ -11,8 +11,10 @@ Capybara.register_driver :poltergeist do |app|
     js_errors: true,
     timeout: timeout,
     window_size: [1366, 768],
+    url_whitelist: %w[localhost 127.0.0.1],
+    url_blacklist: %w[.mp4 .png .gif .avi .bmp .jpg .jpeg],
     phantomjs_options: [
-      '--load-images=no'
+      '--load-images=yes'
     ]
   )
 end

spec/features/help_pages_spec.rb

@@ -34,7 +34,7 @@ describe 'Help Pages', feature: true do
     end
   end
 
-  context 'in a production environment with version check enabled', js: true do
+  context 'in a production environment with version check enabled', :js do
     before do
       allow(Rails.env).to receive(:production?) { true }
       allow(current_application_settings).to receive(:version_check_enabled) { true }
@@ -44,18 +44,12 @@ describe 'Help Pages', feature: true do
       visit help_path
     end
 
-    it 'should display a version check image' do
+    it 'has a version check image' do
-      expect(find('.js-version-status-badge')).to be_visible
+      expect(find('.js-version-status-badge', visible: false)['src']).to end_with('/version-check-url')
     end
 
-    it 'should have a src url' do
+    it 'hides the version check image if the image request fails' do
-      expect(find('.js-version-status-badge')['src']).to match(/\/version-check-url/)
+      # We use '--load-images=yes' with poltergeist so the image fails to load
-    end
-
-    it 'should hide the version check image if the image request fails' do
-      # We use '--load-images=no' with poltergeist so we must trigger manually
-      execute_script("$('.js-version-status-badge').trigger('error');")
-
       expect(find('.js-version-status-badge', visible: false)).not_to be_visible
     end
   end

spec/features/projects/artifacts/file_spec.rb

@@ -39,6 +39,7 @@ feature 'Artifact file', :js, feature: true do
 
   context 'JPG file' do
     before do
+      page.driver.browser.url_blacklist = []
       visit_file('rails_sample.jpg')
 
       wait_for_requests

spec/support/capybara.rb

@@ -14,8 +14,10 @@ Capybara.register_driver :poltergeist do |app|
     js_errors: true,
     timeout: timeout,
     window_size: [1366, 768],
+    url_whitelist: %w[localhost 127.0.0.1],
+    url_blacklist: %w[.mp4 .png .gif .avi .bmp .jpg .jpeg],
     phantomjs_options: [
-      '--load-images=no'
+      '--load-images=yes'
     ]
   )
 end