FEATURE: replace emoji with unicode in title and description meta tags

app/helpers/application_helper.rb

@@ -188,8 +188,9 @@ def crawlable_meta_data(opts=nil)
     [:url, :title, :description].each do |property|
       if opts[property].present?
         escape = (property != :image)
-        result << tag(:meta, { property: "og:#{property}", content: opts[property] }, nil, escape)
-        result << tag(:meta, { name: "twitter:#{property}", content: opts[property] }, nil, escape)
+        content = (property == :url ? opts[property] : gsub_emoji_to_unicode(opts[property]))
+        result << tag(:meta, { property: "og:#{property}", content: content }, nil, escape)
+        result << tag(:meta, { name: "twitter:#{property}", content: content }, nil, escape)
       end
     end
 
@@ -217,6 +218,12 @@ def render_sitelinks_search_tag
     content_tag(:script, MultiJson.dump(json).html_safe, type: 'application/ld+json'.freeze)
   end
 
+  def gsub_emoji_to_unicode(str)
+    if str
+      str.gsub(/:([\w\-+]*):/) { |name| Emoji.lookup_unicode($1) || name }
+    end
+  end
+
   def application_logo_url
     @application_logo_url ||= (mobile_view? && SiteSetting.mobile_logo_url) || SiteSetting.logo_url
   end

spec/helpers/application_helper_spec.rb

@@ -106,4 +106,10 @@
     end
   end
 
+  describe 'gsub_emoji_to_unicode' do
+    it "converts all emoji to unicode" do
+      expect(helper.gsub_emoji_to_unicode('Boat Talk: my :sailboat: boat: why is it so slow? :snail:')).to eq("Boat Talk: my ⛵ boat: why is it so slow? 🐌")
+    end
+  end
+
 end