create favicon overlay on the client

the initial reason for this change was that graphicsmagick does not
support writing to ico files. this fact lead to a chain of changes:

1. use png instead of ico (browser support is good enough)
2. render the overlays on the client using the canvas API. this way we
   only need to store the original favion and generate the overlay versions
   dynamically.
   this change also enables (next step) to simplify the handling of the
   stock favicons as well, as we don't need to generate all the versions
   upfront.

1 files changed, 4 insertions, 23 deletions

diff --git a/spec/features/admin/admin_appearance_spec.rb b/spec/features/admin/admin_appearance_spec.rb
index ffffd14752e..0ac4f111c52 100644
--- a/spec/features/admin/admin_appearance_spec.rb
+++ b/spec/features/admin/admin_appearance_spec.rb
@@ -76,38 +76,19 @@ feature 'Admin Appearance' do
     expect(page).not_to have_css(header_logo_selector)
   end
 
-  scenario 'Favicon' do
+  scenario 'Favicon', :js do
     sign_in(create(:admin))
     visit admin_appearances_path
 
     attach_file(:appearance_favicon, logo_fixture)
     click_button 'Save'
 
-    expect(page).to have_css('//img[data-src$="/default_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_canceled_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_created_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_failed_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_manual_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_not_found_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_pending_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_running_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_skipped_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_success_dk.ico"]')
-    expect(page).to have_css('//img[data-src$="/status_warning_dk.ico"]')
+    # 11 = 1 original + 10 overlay variations
+    expect(page).to have_css('.appearance-light-logo-preview', count: 11)
 
     click_link 'Remove favicon'
 
-    expect(page).not_to have_css('//img[data-src$="/default_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_canceled_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_created_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_failed_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_manual_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_not_found_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_pending_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_running_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_skipped_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_success_dk.ico"]')
-    expect(page).not_to have_css('//img[data-src$="/status_warning_dk.ico"]')
+    expect(page).not_to have_css('.appearance-light-logo-preview')
 
     # allowed file types
     attach_file(:appearance_favicon, Rails.root.join('spec', 'fixtures', 'sanitized.svg'))