allow custom compression for custom Accept-Encoding Fixes expressjs#59

nickdesaulniers · Oct 27, 2015 · 665c0cf · 665c0cf
1 parent 2b4549a
commit 665c0cf
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Showing 3 changed files with 56 additions and 5 deletions.
diff --git a/index.js b/index.js
@@ -173,7 +173,14 @@ function compression(options) {
 
       // compression method
       var accept = accepts(req)
-      var method = accept.encoding(['gzip', 'deflate', 'identity'])
+      var acceptableEncodings = ['gzip', 'deflate', 'identity']
+
+      if (opts.compressor) {
+        acceptableEncodings =
+          Object.keys(opts.compressor).concat(acceptableEncodings)
+      }
+
+      var method = accept.encoding(acceptableEncodings)
 
       // we really don't prefer deflate
       if (method === 'deflate' && accept.encoding(['gzip'])) {
@@ -188,9 +195,13 @@ function compression(options) {
 
       // compression stream
       debug('%s compression', method)
-      stream = method === 'gzip'
-        ? zlib.createGzip(opts)
-        : zlib.createDeflate(opts)
+      if (method === 'gzip') {
+        stream = zlib.createGzip(opts);
+      } else if (method === 'deflate') {
+        stream = zlib.createDeflate(opts);
+      } else if (opts.compressor && method in opts.compressor) {
+        stream = opts.compressor[method];
+      }
 
       // add bufferred listeners to stream
       addListeners(stream, stream.on, listeners)

diff --git a/package.json b/package.json
@@ -19,7 +19,8 @@
   "devDependencies": {
     "istanbul": "0.3.21",
     "mocha": "2.3.3",
-    "supertest": "1.1.0"
+    "supertest": "1.1.0",
+    "through": "^2.3.8"
   },
   "files": [
     "LICENSE",

diff --git a/test/compression.js b/test/compression.js
@@ -3,6 +3,7 @@ var bytes = require('bytes');
 var crypto = require('crypto');
 var http = require('http');
 var request = require('supertest');
+var through = require('through');
 
 var compression = require('..');
 
@@ -492,6 +493,44 @@ describe('compression()', function(){
     })
   })
 
+  describe('when "Accept-Encoding: custom"', function () {
+    it('should not use content encoding without a custom compressor function', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+      .get('/')
+      .set('Accept-Encoding', 'custom')
+      .expect(shouldNotHaveHeader('Content-Encoding'))
+      .expect(200, 'hello, world', done)
+    })
+
+    it('should use content encoding with a custom compressor function', function (done) {
+      var compressor = through(function (d) {
+        this.queue(d)
+      }, function () {
+        this.queue(null)
+      })
+      var opts = {
+        threshold: 0,
+        compressor: {
+          'bingo': compressor
+        }
+      }
+      var server = createServer(opts, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+      .get('/')
+      .set('Accept-Encoding', 'bingo, gzip')
+      .expect('Content-Encoding', 'bingo', done)
+    })
+  })
+
   describe('when "Cache-Control: no-transform" response header', function () {
     it('should not compress response', function (done) {
       var server = createServer({ threshold: 0 }, function (req, res) {