Fix #70 - Better error for .createServer in browser (#73)

* Fix #70 - Better error for .createServer in browser

* Add test for throw

* Make test sync

Author: mkg20001

package.json

@@ -16,7 +16,7 @@
     "coverage-publish": "aegir coverage --provider coveralls"
   },
   "browser": {
-    "pull-ws/server": false
+    "src/listener": "./src/listener.browser.js"
   },
   "pre-push": [
     "lint",

src/listener.browser.js

@@ -0,0 +1,5 @@
+'use strict'
+
+module.exports = function () {
+  throw new Error('WebSocket Servers can not be created in the browser!')
+}

test/browser.js

@@ -75,3 +75,7 @@ describe('libp2p-websockets', () => {
     })
   })
 })
+
+it('.createServer throws in browser', () => {
+  expect(new WS().createListener).to.throw()
+})