Minor refactoring in the tunnel module:

- proxyHeaderWhiteList, proxyHeaderExclusiveList and proxyHeaders
  are no longer public properties of the request instance

lib/tunnel.js

@@ -66,15 +66,15 @@ function constructProxyHeaderWhiteList(headers, proxyHeaderWhiteList) {
     }, {})
 }
 
-function constructTunnelOptions (request) {
+function constructTunnelOptions (request, proxyHeaders) {
   var proxy = request.proxy
 
   var tunnelOptions = {
     proxy : {
       host      : proxy.hostname,
       port      : +proxy.port,
       proxyAuth : proxy.auth,
-      headers   : request.proxyHeaders
+      headers   : proxyHeaders
     },
     headers            : request.headers,
     ca                 : request.ca,
@@ -107,6 +107,8 @@ function getTunnelFn(request) {
 
 function Tunnel (request) {
   this.request = request
+  this.proxyHeaderWhiteList = defaultProxyHeaderWhiteList
+  this.proxyHeaderExclusiveList = []
 }
 
 Tunnel.prototype.isEnabled = function (options) {
@@ -136,10 +138,12 @@ Tunnel.prototype.isEnabled = function (options) {
   return undefined
 }
 
-Tunnel.prototype.setup = function () {
+Tunnel.prototype.setup = function (options) {
   var self = this
     , request = self.request
 
+  options = options || {}
+
   if (typeof request.proxy === 'string') {
     request.proxy = url.parse(request.proxy)
   }
@@ -149,20 +153,26 @@ Tunnel.prototype.setup = function () {
   }
 
   // Setup Proxy Header Exclusive List and White List
-  request.proxyHeaderExclusiveList = request.proxyHeaderExclusiveList || []
-  request.proxyHeaderWhiteList = request.proxyHeaderWhiteList || defaultProxyHeaderWhiteList
-  var proxyHeaderExclusiveList = request.proxyHeaderExclusiveList.concat(defaultProxyHeaderExclusiveList)
-  var proxyHeaderWhiteList = request.proxyHeaderWhiteList.concat(proxyHeaderExclusiveList)
+  if (options.proxyHeaderWhiteList) {
+    self.proxyHeaderWhiteList = options.proxyHeaderWhiteList
+  }
+  if (options.proxyHeaderExclusiveList) {
+    self.proxyHeaderExclusiveList = options.proxyHeaderExclusiveList
+  }
+
+  var proxyHeaderExclusiveList = self.proxyHeaderExclusiveList.concat(defaultProxyHeaderExclusiveList)
+  var proxyHeaderWhiteList = self.proxyHeaderWhiteList.concat(proxyHeaderExclusiveList)
 
   // Setup Proxy Headers and Proxy Headers Host
   // Only send the Proxy White Listed Header names
-  request.proxyHeaders = constructProxyHeaderWhiteList(request.headers, proxyHeaderWhiteList)
-  request.proxyHeaders.host = constructProxyHost(request.uri)
+  var proxyHeaders = constructProxyHeaderWhiteList(request.headers, proxyHeaderWhiteList)
+  proxyHeaders.host = constructProxyHost(request.uri)
+
   proxyHeaderExclusiveList.forEach(request.removeHeader, request)
 
   // Set Agent from Tunnel Data
   var tunnelFn = getTunnelFn(request)
-  var tunnelOptions = constructTunnelOptions(request)
+  var tunnelOptions = constructTunnelOptions(request, proxyHeaders)
   request.agent = tunnelFn(tunnelOptions)
 
   return true

request.js

@@ -295,7 +295,7 @@ Request.prototype.init = function (options) {
 
   self.tunnel = self._tunnel.isEnabled(options)
   if (self.proxy) {
-    self._tunnel.setup()
+    self._tunnel.setup(options)
   }
 
   self._redirect.onRequest(options)