[fixed] fix a bug where binary files were not being properly encoded

when proxied

Proxy server is not working properly when it requests url which expected
to take binary data as response. The problem is encoding in request
options is not set properly. According to 'request' package document,
those requests expected for binary data should set encoding to null. Thus
a new parameter added to 'proxy' function is to set proper encoding to
different situation. [default: undefined]

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 .DS_Store
+.idea
 npm-debug.log

index.js

@@ -5,7 +5,7 @@ var debug = require('debug')('koa-pixie-proxy');
 var hasColons = /:/;
 
 function pixie(options) {
-  return function proxy(path) {
+  return function proxy(path, encoding) {
     var shouldReplacePathParams = hasColons.test(path);
 
     return function* (next) {
@@ -15,7 +15,8 @@ function pixie(options) {
         url: options.host + (path || this.url),
         method: this.method,
         headers: this.headers,
-        qs: this.query
+        qs: this.query,
+        encoding: encoding
       };
 
       // if we have dynamic segments in the url

package.json

@@ -30,4 +30,4 @@
     "mocha": "2.0.1",
     "supertest": "0.15.0"
   }
-}
+}

test/index.js

@@ -3,11 +3,11 @@ var koa = require('koa');
 var supertest = require('supertest');
 var assert = require('assert');
 var http = require('http');
+var fs = require('fs');
 var serve = require('koa-static');
 var router = require('koa-router');
 var body = require('koa-body');
 
-
 function getRandomPort() {
   return Math.ceil(Math.random() * 5000 + 5000);
 }
@@ -40,6 +40,7 @@ function makeTestServer() {
     this.set('x-some-dumb-header', 'Im-set-yo');
     this.body = this.request.body;
   });
+
   return http.createServer(app.callback())
 }
 
@@ -218,4 +219,31 @@ describe('pixie-proxy', function() {
         });
     });
   });
+
+  it('proxies request binary data(image, compressed file, etc.)', function(done){
+    var testServer = makeTestServer();
+    var PORT = getRandomPort();
+    testServer.listen(PORT, function() {
+
+      var app = koa();
+      app.use(body());
+      app.use(router(app));
+
+      var proxy = pixie({host: 'http://localhost:' + PORT});
+
+      app.get('/static/mystery.gif', proxy('', null));
+      supertest(http.createServer(app.callback()))
+        .get('/static/mystery.gif')
+        .expect(200)
+        .expect('Content-Type', 'image/gif')
+        .end(function(err, res){
+          assert.ifError(err);
+          fs.readFile(__dirname + '/static/mystery.gif', 'binary', function(err, data){
+            assert.equal(res.header['content-length'], data.length);
+            testServer.close();
+            done();
+          });
+        });
+    });
+  });
 });