Use destructuring

bot/facebook/index.js

@@ -22,9 +22,9 @@ const fbMessage = async req => {
   req.env = {facebookAppSecret: process.env.FB_APP_SECRET}
   req.rawBody = await text(req)
   const data = await json(req)
-  const message = data.entry.map(
-    entry => entry.messaging.map(message => fbParser(message))[0]
-  )[0]
+  const [[message]] = data.entry.map(entry =>
+    entry.messaging.map(message => fbParser(message))
+  )
 
   const isValid = fbValidate(req) && message.type === 'facebook'