Add emojis:generate_borders Rake task

lib/tasks/emojis.rake

@@ -1,5 +1,37 @@
 # frozen_string_literal: true
 
+def gen_border(codepoint)
+  input = Rails.root.join('public', 'emoji', "#{codepoint}.svg")
+  dest = Rails.root.join('public', 'emoji', "#{codepoint}_border.svg")
+  doc = File.open(input) { |f| Nokogiri::XML(f) }
+  svg = doc.at_css('svg')
+  if svg.key?('viewBox')
+    view_box = svg['viewBox'].split(' ').map(&:to_i)
+    view_box[0] -= 2
+    view_box[1] -= 2
+    view_box[2] += 4
+    view_box[3] += 4
+    svg['viewBox'] = view_box.join(' ')
+  end
+  g = Nokogiri::XML::Node.new 'g', doc
+  doc.css('svg > *').each do |elem|
+    border_elem = elem.dup
+
+    border_elem.delete('fill')
+    border_elem['stroke'] = 'white'
+
+    style = border_elem['style'] || ''
+    old_width = border_elem['stroke-width'] || '0px'
+    style += " stroke-width: calc(#{old_width} + 4px)"
+    border_elem['style'] = style.strip
+
+    g.add_child(border_elem)
+  end
+  svg.prepend_child(g)
+  File.write(dest, doc.to_xml)
+  puts "Wrote bordered #{codepoint}.svg to #{dest}!"
+end
+
 def codepoints_to_filename(codepoints)
   codepoints.downcase.gsub(/\A[0]+/, '').tr(' ', '-')
 end
@@ -23,8 +55,10 @@ namespace :emojis do
 
     HTTP.get(source).to_s.split("\n").each do |line|
       next if line.start_with? '#'
+
       parts = line.split(';').map(&:strip)
       next if parts.size < 2
+
       codes << [parts[0], parts[1].start_with?('fully-qualified')]
     end
 
@@ -55,4 +89,12 @@ namespace :emojis do
     File.write(dest, Oj.dump(map))
     puts "Wrote emojo to destination! (#{dest})"
   end
+
+  desc 'Generate emoji variants with white borders'
+  task :generate_borders do
+    codepoints = %w(1f3b1 1f41c 1f519 26ab 1f5a4 2b1b 25fe 25fc 2712 25aa 1f4a3 1f3b3 1f464 1f465 1f4f7 1f4f8 2663 27b0 1f4b1 1f576 2734 1f50c 1f51a 1f482-200d-2640-fe0f 1f482-1f3fb-200d-2640-fe0f 1f482-1f3fc-200d-2640-fe0f 1f482-1f3fd-200d-2640-fe0f 1f482-1f3fe-200d-2640-fe0f 1f482-1f3ff-200d-2640-fe0f 1f4fd 1f373 1f98d 1f482 1f482-1f3fb 1f482-1f3fc 1f482-1f3fd 1f482-1f3fe 1f482-1f3ff 2714 2797 1f4b2 2796 2716 2795 1f52a 1f573 1f579 1f54b 1f58a 1f58b 1f482-200d-2642-fe0f 1f482-1f3fb-200d-2642-fe0f 1f482-1f3fc-200d-2642-fe0f 1f482-1f3fd-200d-2642-fe0f 1f482-1f3fe-200d-2642-fe0f 1f482-1f3ff-200d-2642-fe0f 1f3a4 1f393 1f3a5 1f3bc 1f51b 1f51c 2660 1f5e3 1f577 1f4de 2122 1f51d 1f3a9 1f983 1f4fc 1f4f9 1f3ae 1f403 1f3f4 3030)
+    codepoints.each do |cc|
+      gen_border cc
+    end
+  end
 end