fix: better ws errors

Author: fsdiogo

src/errors/index.js

@@ -0,0 +1,3 @@
+'use strict'
+
+exports.ERR_WS_STAR_WEBSOCKET_CONNECTION = 'ERR_WS_STAR_WEBSOCKET_CONNECTION'

src/listener.js

@@ -14,6 +14,7 @@ const setImmediate = require('async/setImmediate')
 const utils = require('./utils')
 const cleanUrlSIO = utils.cleanUrlSIO
 const crypto = require('libp2p-crypto')
+const ERRORS = require('./errors')
 
 const noop = once(() => {})
 
@@ -214,6 +215,15 @@ class Listener extends EE {
       (cb) => this._crypto(cb)
     ], (err) => {
       if (err) {
+        // Error connecting to WebSocket
+        if (err.description && err.description.code === 'ENOTFOUND') {
+          const hostname = err.description.hostname
+
+          err = Object.assign(new Error(`WebSocket connection failed on ${hostname}`), {
+            code: ERRORS.ERR_WS_STAR_WEBSOCKET_CONNECTION
+          })
+        }
+
         this.log('error', err)
         if (!(err instanceof Error)) err = new Error(err)
         this._down()