FIX: convert emoji to unicode on event title (#530)

app/serializers/discourse_post_event/event_summary_serializer.rb

@@ -24,6 +24,10 @@ module DiscoursePostEvent
         },
       }
 
+      if post_hash[:topic][:title].match?(/:[\w\-+]+:/)
+        post_hash[:topic][:title] = Emoji.gsub_emoji_to_unicode(post_hash[:topic][:title])
+      end
+
       if JSON.parse(SiteSetting.map_events_to_color).size > 0
         post_hash[:topic][:category_slug] = object.post.topic&.category&.slug
         post_hash[:topic][:tags] = object.post.topic.tags&.map(&:name)

spec/serializers/discourse_post_event/event_summary_serializer_spec.rb

@@ -8,7 +8,7 @@ describe DiscoursePostEvent::EventSummarySerializer do
   end
 
   fab!(:category)
-  fab!(:topic) { Fabricate(:topic, category: category) }
+  fab!(:topic) { Fabricate(:topic, category: category, title: "Topic title :tada:") }
   fab!(:post) { Fabricate(:post, topic: topic) }
   fab!(:event) { Fabricate(:event, post: post) }
 
@@ -20,7 +20,7 @@ describe DiscoursePostEvent::EventSummarySerializer do
     expect(summary[:timezone]).to eq(event.timezone)
     expect(summary[:name]).to eq(event.name)
     expect(summary[:post][:url]).to eq(post.url)
-    expect(summary[:post][:topic][:title]).to eq(topic.title)
+    expect(summary[:post][:topic][:title]).to eq("Topic title 🎉")
     expect(summary[:category_id]).to eq(category.id)
   end