React with certain probabilty

main.js

@@ -19,6 +19,8 @@ const client = new Discord.Client();
 const parser = new RSSParser();
 const RSS_UPDATE_INTERVAL_MIN = 5;
 
+const REACT_PROBABILITY = 0.6;
+
 async function checkFeeds() {
     let feeds = db.get("rssFeeds").value();
     let outlets = db.get("feedOutputs").value();
@@ -172,4 +174,9 @@ client.on("message", m => {
     }
 });
 
+client.on("messageReactionAdd", (r, u) => {
+    if(Math.random() <= REACT_PROBABILITY && !r.me)
+        r.message.react(r.emoji);
+});
+
 client.login(TOKEN);