[major] Drop support for Node.js 6

.travis.yml

@@ -3,7 +3,6 @@ node_js:
   - '11'
   - '10'
   - '8'
-  - '6'
 os:
   - linux
   - osx

appveyor.yml

@@ -3,7 +3,6 @@ environment:
     - nodejs_version: '11'
     - nodejs_version: '10'
     - nodejs_version: '8'
-    - nodejs_version: '6'
 platform:
   - x86
 matrix:

lib/websocket.js

@@ -1,12 +1,12 @@
 'use strict';
 
 const EventEmitter = require('events');
-const crypto = require('crypto');
 const https = require('https');
 const http = require('http');
 const net = require('net');
 const tls = require('tls');
-const url = require('url');
+const { randomBytes, createHash } = require('crypto');
+const { URL } = require('url');
 
 const PerMessageDeflate = require('./permessage-deflate');
 const EventTarget = require('./event-target');
@@ -480,10 +480,7 @@ function initAsClient(websocket, address, protocols, options) {
     parsedUrl = address;
     websocket.url = address.href;
   } else {
-    //
-    // The WHATWG URL constructor is not available on Node.js < 6.13.0
-    //
-    parsedUrl = url.URL ? new url.URL(address) : url.parse(address);
+    parsedUrl = new URL(address);
     websocket.url = address;
   }
 
@@ -496,7 +493,7 @@ function initAsClient(websocket, address, protocols, options) {
   const isSecure =
     parsedUrl.protocol === 'wss:' || parsedUrl.protocol === 'https:';
   const defaultPort = isSecure ? 443 : 80;
-  const key = crypto.randomBytes(16).toString('base64');
+  const key = randomBytes(16).toString('base64');
   const get = isSecure ? https.get : http.get;
   const path = parsedUrl.search
     ? `${parsedUrl.pathname || '/'}${parsedUrl.search}`
@@ -588,9 +585,7 @@ function initAsClient(websocket, address, protocols, options) {
 
       req.abort();
 
-      const addr = url.URL
-        ? new url.URL(location, address)
-        : url.resolve(address, location);
+      const addr = new URL(location, address);
 
       initAsClient(websocket, addr, protocols, options);
     } else if (!websocket.emit('unexpected-response', req, res)) {
@@ -613,8 +608,7 @@ function initAsClient(websocket, address, protocols, options) {
 
     req = websocket._req = null;
 
-    const digest = crypto
-      .createHash('sha1')
+    const digest = createHash('sha1')
       .update(key + GUID)
       .digest('base64');
 
@@ -676,13 +670,7 @@ function initAsClient(websocket, address, protocols, options) {
  * @private
  */
 function netConnect(options) {
-  //
-  // Override `options.path` only if `options` is a copy of the original options
-  // object. This is always true on Node.js >= 8 but not on Node.js 6 where
-  // `options.socketPath` might be `undefined` even if the `socketPath` option
-  // was originally set.
-  //
-  if (options.protocolVersion) options.path = options.socketPath;
+  options.path = options.socketPath;
   return net.connect(options);
 }
 

test/websocket.test.js

@@ -37,8 +37,6 @@ describe('WebSocket', () => {
     });
 
     it('accepts `url.URL` objects as url', function(done) {
-      if (!url.URL) return this.skip();
-
       const agent = new CustomAgent();
 
       agent.addRequest = (req, opts) => {