fix: IS_BROWSER check is now safer and more agnostic about the bundler (

#1571)

lib/connect/index.js

@@ -2,14 +2,14 @@
 
 const MqttClient = require('../client')
 const Store = require('../store')
+const IS_BROWSER = require('../is-browser').IS_BROWSER
 const url = require('url')
 const xtend = require('xtend')
 const debug = require('debug')('mqttjs')
 
 const protocols = {}
 
-// eslint-disable-next-line camelcase
-if ((typeof process !== 'undefined' && process.title !== 'browser') || typeof __webpack_require__ !== 'function') {
+if (!IS_BROWSER) {
   protocols.mqtt = require('./tcp')
   protocols.tcp = require('./tcp')
   protocols.ssl = require('./tls')

lib/connect/ws.js

@@ -5,6 +5,7 @@ const WS = require('ws')
 const debug = require('debug')('mqttjs:ws')
 const duplexify = require('duplexify')
 const Transform = require('readable-stream').Transform
+const IS_BROWSER = require('../is-browser').IS_BROWSER
 
 const WSS_OPTIONS = [
   'rejectUnauthorized',
@@ -14,8 +15,7 @@ const WSS_OPTIONS = [
   'pfx',
   'passphrase'
 ]
-// eslint-disable-next-line camelcase
-const IS_BROWSER = (typeof process !== 'undefined' && process.title === 'browser') || typeof __webpack_require__ === 'function'
+
 function buildUrl (opts, client) {
   let url = opts.protocol + '://' + opts.hostname + ':' + opts.port + opts.path
   if (typeof (opts.transformWsUrl) === 'function') {

lib/is-browser.js

@@ -0,0 +1,11 @@
+const legacyIsBrowser =
+(typeof process !== 'undefined' && process.title === 'browser') ||
+// eslint-disable-next-line camelcase
+  typeof __webpack_require__ === 'function'
+
+const isBrowser =
+  typeof window !== 'undefined' && typeof document !== 'undefined'
+
+module.exports = {
+  IS_BROWSER: isBrowser || legacyIsBrowser
+}