Callback implementation and tests for write and end

HISTORY.md

@@ -1,6 +1,9 @@
 unreleased
 ==========
 
+1.7.0 / 2017-01-04
+==================
+  * Callbacks available in `write` and `end` when supported in nodejs (requires nodejs >= 0.12.x)
   * deps: [email protected]
   * deps: compressible@~2.0.9
     - Fix regex fallback to not override `compressible: false` in db

index.js

@@ -21,6 +21,7 @@ var debug = require('debug')('compression')
 var onHeaders = require('on-headers')
 var vary = require('vary')
 var zlib = require('zlib')
+var http = require('http')
 
 /**
  * Module exports.
@@ -35,6 +36,7 @@ module.exports.filter = shouldCompress
  */
 
 var cacheControlNoTransformRegExp = /(?:^|,)\s*?no-transform\s*?(?:,|$)/
+var nodeHasCallbacks = (http.OutgoingMessage.prototype.write.length === 3 && http.OutgoingMessage.prototype.end.length === 3)
 
 /**
  * Compress response data with gzip / deflate.
@@ -74,7 +76,7 @@ function compression (options) {
 
     // proxy
 
-    res.write = function write (chunk, encoding) {
+    res.write = function write (chunk, encoding, cb) {
       if (ended) {
         return false
       }
@@ -84,11 +86,11 @@ function compression (options) {
       }
 
       return stream
-        ? stream.write(new Buffer(chunk, encoding))
-        : _write.call(this, chunk, encoding)
+        ? stream.write(new Buffer(chunk, encoding), nodeHasCallbacks ? cb : undefined)
+        : _write.call(this, chunk, encoding, nodeHasCallbacks ? cb : undefined)
     }
 
-    res.end = function end (chunk, encoding) {
+    res.end = function end (chunk, encoding, cb) {
       if (ended) {
         return false
       }
@@ -103,16 +105,16 @@ function compression (options) {
       }
 
       if (!stream) {
-        return _end.call(this, chunk, encoding)
+        return _end.call(this, chunk, encoding, nodeHasCallbacks ? cb : undefined)
       }
 
       // mark ended
       ended = true
 
       // write Buffer for Node.js 0.8
       return chunk
-        ? stream.end(new Buffer(chunk, encoding))
-        : stream.end()
+        ? stream.end(new Buffer(chunk, encoding), nodeHasCallbacks ? cb : undefined)
+        : stream.end(null, null, nodeHasCallbacks ? cb : undefined)
     }
 
     res.on = function on (type, listener) {

package.json

@@ -1,7 +1,7 @@
 {
   "name": "compression",
   "description": "Node.js compression middleware",
-  "version": "1.6.2",
+  "version": "1.7.0",
   "contributors": [
     "Douglas Christopher Wilson <[email protected]>",
     "Jonathan Ong <[email protected]> (http://jongleberry.com)"

test/compression.js

@@ -676,6 +676,81 @@ describe('compression()', function () {
       .end()
     })
   })
+
+  describe('when callbacks are used', function () {
+    it('should call the passed callbacks in the order passed when compressing', function (done) {
+      var hasCallbacks = false
+      var callbackOutput = []
+      var server = createServer(null, function (req, res) {
+        hasCallbacks = (http.OutgoingMessage.prototype.write.length === 3 && http.OutgoingMessage.prototype.end.length === 3)
+        res.setHeader('Content-Type', 'text/plain')
+        res.write('Hello', null, function () {
+          callbackOutput.push(0)
+        })
+        res.write(' World', null, function () {
+          callbackOutput.push(1)
+        })
+        res.end(null, null, function () {
+          callbackOutput.push(2)
+        })
+      })
+
+      request(server)
+      .get('/')
+      .set('Accept-Encoding', 'gzip')
+      .expect('Content-Encoding', 'gzip')
+      .end(function (err) {
+        if (err) {
+          throw new Error(err)
+        }
+        if (hasCallbacks) {
+          assert.equal(callbackOutput.length, 3)
+          assert.deepEqual(callbackOutput, [0, 1, 2])
+        } else {
+          // nodejs 0.10 zlib has callbacks but OutgoingMessage doesn't, assert that no callbacks were made
+          assert.equal(callbackOutput.length, 0)
+        }
+        done()
+      })
+    })
+
+    it('should call the passed callbacks in the order passed when not compressing', function (done) {
+      var hasCallbacks = false
+      var callbackOutput = []
+      var server = createServer(null, function (req, res) {
+        hasCallbacks = (http.OutgoingMessage.prototype.write.length === 3 && http.OutgoingMessage.prototype.end.length === 3)
+        res.setHeader('Cache-Control', 'no-transform')
+        res.setHeader('Content-Type', 'text/plain')
+        res.write('hello,', null, function () {
+          callbackOutput.push(0)
+        })
+        res.write(' world', null, function () {
+          callbackOutput.push(1)
+        })
+        res.end(null, null, function () {
+          callbackOutput.push(2)
+        })
+      })
+
+      request(server)
+      .get('/')
+      .set('Accept-Encoding', 'gzip')
+      .expect('Cache-Control', 'no-transform')
+      .expect(shouldNotHaveHeader('Content-Encoding'))
+      .end(function (err) {
+        if (err) {
+          throw new Error(err)
+        }
+        if (hasCallbacks) {
+          assert.equal(callbackOutput.length, 3)
+          assert.deepEqual(callbackOutput, [0, 1, 2])
+        } else {
+          assert.equal(callbackOutput.length, 0)
+        }
+        done()
+      })
+    })
+  })
 })
 
 function createServer (opts, fn) {