favicon uploader generating ci status favicons

Gemfile

@@ -104,6 +104,7 @@ gem 'hamlit', '~> 2.6.1'
 
 # Files attachments
 gem 'carrierwave', '~> 1.2'
+gem 'mini_magick'
 
 # Drag and Drop UI
 gem 'dropzonejs-rails', '~> 0.7.1'

Gemfile.lock

@@ -494,6 +494,7 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
     mimemagic (0.3.0)
+    mini_magick (4.8.0)
     mini_mime (1.0.0)
     mini_portile2 (2.3.0)
     minitest (5.7.0)
@@ -1078,6 +1079,7 @@ DEPENDENCIES
   loofah (~> 2.2)
   mail_room (~> 0.9.1)
   method_source (~> 0.8)
+  mini_magick
   minitest (~> 5.7.0)
   mousetrap-rails (~> 1.4.6)
   mysql2 (~> 0.4.10)

app/uploaders/favicon_uploader.rb

+class FaviconUploader < AttachmentUploader
+  include CarrierWave::MiniMagick
+
+  STATUS_ICON_NAMES = [
+    :status_not_found,
+    :status_canceled,
+    :status_success,
+    :status_skipped,
+    :status_created,
+    :status_failed,
+    :status_warning,
+    :status_pending,
+    :status_manual,
+    :status_running
+  ].freeze
+
+  version :default_without_format_conversion do
+    process resize_to_fill: [32, 32]
+  end
+
+  # this intermediate version generates an image in the ico format but with the
+  # original file suffix.
+  version :_default, from_version: :default_without_format_conversion do
+    process convert: 'ico'
+  end
+
+  version :default, from_version: :_default
+
+  STATUS_ICON_NAMES.each do |status_name|
+    version status_name, from_version: :default do
+      process status_favicon: status_name
+    end
+  end
+
+  def status_favicon(status_name)
+    manipulate! do |img|
+      overlay_path = Rails.root.join("app/assets/images/ci_favicons/overlays/favicon_#{status_name}.png")
+      overlay = MiniMagick::Image.open(overlay_path)
+      img.composite(overlay) do |c|
+        c.compose 'over'
+      end
+    end
+  end
+end

spec/uploaders/favicon_uploader_spec.rb

+require 'spec_helper'
+
+RSpec.describe FaviconUploader do
+  include CarrierWave::Test::Matchers
+
+  let(:uploader) { described_class.new(build_stubbed(:user)) }
+
+  after do
+    uploader.remove!
+  end
+
+  def upload_fixture(filename)
+    fixture_file_upload(Rails.root.join('spec', 'fixtures', filename))
+  end
+
+  context 'versions' do
+    before do
+      uploader.store!(upload_fixture('dk.png'))
+    end
+
+    it 'has the correct format' do
+      expect(uploader.default).to be_format('ico')
+    end
+
+    it 'has the correct dimensions' do
+      expect(uploader.default).to have_dimensions(32, 32)
+    end
+
+    it 'generates all the status icons' do
+      # make sure that the following each statement actually loops
+      expect(FaviconUploader::STATUS_ICON_NAMES.count).to eq 10
+
+      FaviconUploader::STATUS_ICON_NAMES.each do |status_name|
+        expect(File.exist?(uploader.status_not_found.file.file)).to be true
+      end
+    end
+  end
+end