[api] ensure before/after options are proper streams for doing arbitrary transformation on requests

Author: jcrugzz

lib/http-proxy/passes/web-incoming.js

@@ -2,6 +2,8 @@ var http   = require('http'),
     https  = require('https'),
     web_o  = require('./web-outgoing'),
     common = require('../common'),
+    PassThrough = require('stream').PassThrough,
+    isDuplex = require('isstream').isDuplex,
     passes = exports;
 
 web_o = Object.keys(web_o).map(function(pass) {
@@ -93,14 +95,23 @@ web_o = Object.keys(web_o).map(function(pass) {
 
   function stream(req, res, options, _, server, clb) {
 
+    //
+    // Enable arbitary transform/duplex streams to be used on the byte streams
+    //
+    var before = isDuplex(options.before) ? options.before : new PassThrough();
+    var after = isDuplex(options.after) ? options.after : new PassThrough();
+
+    before.on('error', proxyError);
+    after.on('error', proxyError);
+
     // And we begin!
     server.emit('start', req, res, options.target)
     if(options.forward) {
       // If forward enable, so just pipe the request
       var forwardReq = (options.forward.protocol === 'https:' ? https : http).request(
         common.setupOutgoing(options.ssl || {}, options, req, 'forward')
       );
-      (options.buffer || req).pipe(forwardReq);
+      (options.buffer || req).pipe(before).pipe(forwardReq);
       if(!options.target) { return res.end(); }
     }
 
@@ -141,7 +152,7 @@ web_o = Object.keys(web_o).map(function(pass) {
       }
     }
 
-    (options.buffer || req).pipe(proxyReq);
+    (options.buffer || req).pipe(before).pipe(proxyReq);
 
     proxyReq.on('response', function(proxyRes) {
       if(server) { server.emit('proxyRes', proxyRes, req, res); }
@@ -154,7 +165,7 @@ web_o = Object.keys(web_o).map(function(pass) {
         server.emit('end', req, res, proxyRes);
       });
 
-      proxyRes.pipe(res);
+      proxyRes.pipe(after).pipe(res);
     });
 
     //proxyReq.end();