Merge branch 'pr-177'

This closes #177

Author: kinow

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 2021-??-?? - 1.3.1
+
+- [177](https://github.com/Smashing/smashing/pull/177) Remove websocket connections that have been closed in send_event (thanks @ssgelm)
+
 ## 2020-06-04 - 1.3.0
 
 - [#157](https://github.com/Smashing/smashing/pull/157) Update gems

lib/dashing/app.rb

@@ -144,7 +144,13 @@ def send_event(id, body, target=nil)
   body[:updatedAt] ||= (Time.now.to_f * 1000.0).to_i 
   event = format_event(body.to_json, target)
   Sinatra::Application.settings.history[id] = event unless target == 'dashboards'
-  Sinatra::Application.settings.connections.each { |out| out << event }
+  Sinatra::Application.settings.connections.each { |out|
+    begin
+      out << event
+    rescue IOError => e # if the socket is closed an IOError is thrown
+      Sinatra::Application.settings.connections.delete(out)
+    end
+  }
 end
 
 def format_event(body, name=nil)