Include websocket non-upgrade response

When the server do not accept the upgrade request for websockets the
server's response was previously not included and sent back. Now the
proxy will include the response in these cases. Fixes #890.

Author: Tigge

Diff for: lib/http-proxy/passes/ws-incoming.js

@@ -77,6 +77,24 @@ module.exports = {
    * @api private
    */
   stream : function stream(req, socket, options, head, server, clb) {
+
+    var createHttpHeader = function(line, headers) {
+      return Object.keys(headers).reduce(function (head, key) {
+        var value = headers[key];
+
+        if (!Array.isArray(value)) {
+          head.push(key + ': ' + value);
+          return head;
+        }
+
+        for (var i = 0; i < value.length; i++) {
+          head.push(key + ': ' + value[i]);
+        }
+        return head;
+      }, [line])
+      .join('\r\n') + '\r\n\r\n';
+    }
+
     common.setupSocket(socket);
 
     if (head && head.length) socket.unshift(head);
@@ -93,7 +111,10 @@ module.exports = {
     proxyReq.on('error', onOutgoingError);
     proxyReq.on('response', function (res) {
       // if upgrade event isn't going to happen, close the socket
-      if (!res.upgrade) socket.end();
+      if (!res.upgrade) {
+        socket.write(createHttpHeader('HTTP/' + res.httpVersion + ' ' + res.statusCode + ' ' + res.statusMessage, res.headers));
+        res.pipe(socket);
+      }
     });
 
     proxyReq.on('upgrade', function(proxyRes, proxySocket, proxyHead) {
@@ -119,22 +140,7 @@ module.exports = {
       // Remark: Handle writing the headers to the socket when switching protocols
       // Also handles when a header is an array
       //
-      socket.write(
-        Object.keys(proxyRes.headers).reduce(function (head, key) {
-          var value = proxyRes.headers[key];
-
-          if (!Array.isArray(value)) {
-            head.push(key + ': ' + value);
-            return head;
-          }
-
-          for (var i = 0; i < value.length; i++) {
-            head.push(key + ': ' + value[i]);
-          }
-          return head;
-        }, ['HTTP/1.1 101 Switching Protocols'])
-        .join('\r\n') + '\r\n\r\n'
-      );
+      socket.write(createHttpHeader('HTTP/1.1 101 Switching Protocols', proxyRes.headers));
 
       proxySocket.pipe(socket).pipe(proxySocket);
 

Diff for: test/lib-http-proxy-test.js

@@ -415,7 +415,6 @@ describe('lib/http-proxy.js', function() {
 
       client.on('error', function (err) {
         expect(err).to.be.an(Error);
-        expect(err.code).to.be('ECONNRESET');
         proxyServer.close();
         done();
       });