use vary module

closes #10

Author: dougwilson

index.js

@@ -14,6 +14,7 @@ var accepts = require('accepts');
 var bytes = require('bytes');
 var onHeaders = require('on-headers');
 var compressible = require('compressible');
+var vary = require('vary');
 
 /**
  * Supported content-encoding methods.
@@ -196,29 +197,3 @@ function addListeners(stream, on, listeners) {
 }
 
 function noop(){}
-
-/**
- * Add val to Vary header
- */
-
-function vary(res, val) {
-  var header = res.getHeader('Vary') || ''
-  var headers = Array.isArray(header)
-    ? header.join(', ')
-    : header
-
-  // enumerate current values
-  var vals = headers.toLowerCase().split(/ *, */)
-
-  if (vals.indexOf(val.toLowerCase()) !== -1) {
-    // already set
-    return
-  }
-
-  // append value (in existing format)
-  header = headers
-    ? headers + ', ' + val
-    : val
-
-  res.setHeader('Vary', header)
-}

package.json

@@ -20,7 +20,8 @@
     "accepts": "1.0.2",
     "bytes": "1.0.0",
     "compressible": "1.1.0",
-    "on-headers": "0.0.0"
+    "on-headers": "0.0.0",
+    "vary": "0.0.0"
   },
   "devDependencies": {
     "istanbul": "0.2.10",

test/test.js

@@ -77,48 +77,6 @@ describe('compress()', function(){
     .expect('Vary', 'Accept-Encoding', done)
   })
 
-  it('should append to Vary', function(done){
-    var server = createServer({ threshold: 0 }, function (req, res) {
-      res.setHeader('Content-Type', 'text/plain')
-      res.setHeader('Vary', 'User-Agent')
-      res.end('hello, world')
-    })
-
-    request(server)
-    .get('/')
-    .set('Accept-Encoding', 'gzip')
-    .expect('Content-Encoding', 'gzip')
-    .expect('Vary', 'User-Agent, Accept-Encoding', done)
-  })
-
-  it('should append to Vary when array', function(done){
-    var server = createServer({ threshold: 0 }, function (req, res) {
-      res.setHeader('Content-Type', 'text/plain')
-      res.setHeader('Vary', ['User-Agent', 'Origin'])
-      res.end('hello, world')
-    })
-
-    request(server)
-    .get('/')
-    .set('Accept-Encoding', 'gzip')
-    .expect('Content-Encoding', 'gzip')
-    .expect('Vary', 'User-Agent, Origin, Accept-Encoding', done)
-  })
-
-  it('should not double-append to Vary', function(done){
-    var server = createServer({ threshold: 0 }, function (req, res) {
-      res.setHeader('Content-Type', 'text/plain')
-      res.setHeader('Vary', 'Accept-Encoding, User-Agent')
-      res.end('hello, world')
-    })
-
-    request(server)
-    .get('/')
-    .set('Accept-Encoding', 'gzip')
-    .expect('Content-Encoding', 'gzip')
-    .expect('Vary', 'Accept-Encoding, User-Agent', done)
-  })
-
   it('should set Vary even if Accept-Encoding is not set', function(done){
     var server = createServer({ threshold: 1000 }, function (req, res) {
       res.setHeader('Content-Type', 'text/plain')