Bump version to 0.1.4.

.npmignore

@@ -2,5 +2,6 @@
 .gitignore
 .npmignore
 .travis.yml
+examples
 node_modules
 spec

.travis.yml

@@ -1,10 +1,16 @@
+sudo: false
 language: node_js
 
 node_js:
   - "0.6"
   - "0.8"
   - "0.10"
-  - "0.11"
+  - "0.12"
+  - "iojs-1"
+  - "iojs-2"
+  - "iojs-3"
+  - "4"
+  - "5"
 
 before_install:
   - '[ "${TRAVIS_NODE_VERSION}" = "0.6" ] && npm conf set strict-ssl false || true'

CHANGELOG.md

@@ -1,3 +1,13 @@
+### 0.1.4 / 2015-11-06
+
+* The server does not send `server_max_window_bits` if the client does not ask
+  for it; this works around an issue in Firefox.
+
+### 0.1.3 / 2015-04-10
+
+* Fix a race condition causing some fragments of deflate output to be dropped
+* Make sure to emit minimal output on all Node versions
+
 ### 0.1.2 / 2014-12-18
 
 * Don't allow configure() to be called with unrecognized options

README.md

@@ -72,22 +72,21 @@ can be used to set the local session's behaviour and control that of the peer:
 
 (The MIT License)
 
-Copyright (c) 2014 James Coglan
+Copyright (c) 2014-2015 James Coglan
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the 'Software'), to deal in
 the Software without restriction, including without limitation the rights to
-use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-of the Software, and to permit persons to whom the Software is furnished to do
-so, subject to the following conditions:
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

examples/roundtrip.js

@@ -0,0 +1,52 @@
+var fs      = require('fs'),
+    deflate = require('..');
+
+var records = fs.readFileSync(__dirname + '/bad.out.log', 'utf8')
+              .replace(/\s*$/g, '')
+              .split(/\n/)
+              .map(JSON.parse);
+
+var client     = deflate.createClientSession(),
+    offer      = client.generateOffer(),
+    server     = deflate.createServerSession([offer]),
+    response   = server.generateResponse(),
+    compressed = [],
+    size       = [0, 0];
+
+client.activate(response);
+
+function compress(index) {
+  var record = records[index];
+  if (!record) {
+    console.log(size, size[0] / size[1]);
+    return decompress(0);
+  }
+
+  var message = {data: new Buffer(record[3], 'base64')};
+  size[0] += message.data.length;
+
+  server.processOutgoingMessage(message, function(error, message) {
+    compressed[index] = message;
+    size[1] += message.data.length;
+    compress(index + 1);
+  });
+}
+
+function decompress(index) {
+  var record = records[index];
+  if (!record) return;
+
+  var payload = record[3],
+      message = compressed[index];
+
+  client.processIncomingMessage(message, function(error, message) {
+    var output = message.data.toString('base64');
+    if (output !== payload) {
+      console.error('Failed on', record, message);
+      process.exit(1);
+    }
+    decompress(index + 1);
+  });
+}
+
+compress(0);

lib/client_session.js

@@ -64,12 +64,12 @@ ClientSession.prototype.activate = function(params) {
 
   this._ownContextTakeover = !(this._acceptNoContextTakeover || params.client_no_context_takeover);
   this._ownWindowBits = Math.min(
-    this._acceptMaxWindowBits || common.DEFAULT_MAX_WINDOW_BITS,
-    params.client_max_window_bits || common.DEFAULT_MAX_WINDOW_BITS
+    this._acceptMaxWindowBits || common.MAX_WINDOW_BITS,
+    params.client_max_window_bits || common.MAX_WINDOW_BITS
   );
 
   this._peerContextTakeover = !params.server_no_context_takeover;
-  this._peerWindowBits = params.server_max_window_bits || common.DEFAULT_MAX_WINDOW_BITS;
+  this._peerWindowBits = params.server_max_window_bits || common.MAX_WINDOW_BITS;
 
   return true;
 };

lib/common.js

@@ -8,7 +8,7 @@ var common = {
     'client_max_window_bits'
   ],
 
-  DEFAULT_MAX_WINDOW_BITS: 15,
+  MAX_WINDOW_BITS:   15,
   VALID_WINDOW_BITS: [8, 9, 10, 11, 12, 13, 14, 15],
 
   concat: function(buffers, length) {

lib/server_session.js

@@ -21,42 +21,46 @@ ServerSession.validParams = function(params) {
 };
 
 ServerSession.prototype.generateResponse = function() {
-  var params = {};
+  var response = {};
 
   // https://tools.ietf.org/html/draft-ietf-hybi-permessage-compression#section-8.1.1.1
-  if (this._acceptNoContextTakeover || this._params.server_no_context_takeover)
-    params.server_no_context_takeover = true;
+
+  this._ownContextTakeover = !this._acceptNoContextTakeover &&
+                             !this._params.server_no_context_takeover;
+
+  if (!this._ownContextTakeover) response.server_no_context_takeover = true;
 
   // https://tools.ietf.org/html/draft-ietf-hybi-permessage-compression#section-8.1.1.2
-  if (this._requestNoContextTakeover || this._params.client_no_context_takeover)
-    params.client_no_context_takeover = true;
+
+  this._peerContextTakeover = !this._requestNoContextTakeover &&
+                              !this._params.client_no_context_takeover;
+
+  if (!this._peerContextTakeover) response.client_no_context_takeover = true;
 
   // https://tools.ietf.org/html/draft-ietf-hybi-permessage-compression#section-8.1.2.1
-  var acceptMax, serverMax;
-  if (this._acceptMaxWindowBits || this._params.server_max_window_bits) {
-    acceptMax = this._acceptMaxWindowBits || common.DEFAULT_MAX_WINDOW_BITS;
-    serverMax = this._params.server_max_window_bits || common.DEFAULT_MAX_WINDOW_BITS;
-    params.server_max_window_bits = Math.min(acceptMax, serverMax);
-  }
+
+  this._ownWindowBits = Math.min(this._acceptMaxWindowBits || common.MAX_WINDOW_BITS,
+                                 this._params.server_max_window_bits || common.MAX_WINDOW_BITS);
+
+  // In violation of the spec, Firefox closes the connection if it does not
+  // send server_max_window_bits but the server includes this in its response
+  if (this._ownWindowBits < common.MAX_WINDOW_BITS && this._params.server_max_window_bits)
+    response.server_max_window_bits = this._ownWindowBits;
 
   // https://tools.ietf.org/html/draft-ietf-hybi-permessage-compression#section-8.1.2.2
+
   var clientMax = this._params.client_max_window_bits, requestMax;
   if (clientMax) {
-    if (clientMax === true) {
-      if (this._requestMaxWindowBits) params.client_max_window_bits = this._requestMaxWindowBits;
-    } else {
-      requestMax = this._requestMaxWindowBits || common.DEFAULT_MAX_WINDOW_BITS;
-      params.client_max_window_bits = Math.min(requestMax, clientMax);
-    }
+    if (clientMax === true) clientMax = common.MAX_WINDOW_BITS;
+    this._peerWindowBits = Math.min(this._requestMaxWindowBits || common.MAX_WINDOW_BITS, clientMax);
+  } else {
+    this._peerWindowBits = common.MAX_WINDOW_BITS;
   }
 
-  this._ownContextTakeover = !params.server_no_context_takeover;
-  this._ownWindowBits = params.server_max_window_bits || common.DEFAULT_MAX_WINDOW_BITS;
+  if (this._peerWindowBits < common.MAX_WINDOW_BITS)
+    response.client_max_window_bits = this._peerWindowBits;
 
-  this._peerContextTakeover = !params.client_no_context_takeover;
-  this._peerWindowBits = params.client_max_window_bits || common.DEFAULT_MAX_WINDOW_BITS;
-
-  return params;
+  return response;
 };
 
 module.exports = ServerSession;

lib/session.js

@@ -3,8 +3,6 @@
 var zlib   = require('zlib'),
     common = require('./common');
 
-var VERSION = process.version.match(/\d+/g).map(function(n) { return parseInt(n, 10) });
-
 var Session = function(options) {
   this._level    = common.fetch(options, 'level',    zlib.Z_DEFAULT_LEVEL);
   this._memLevel = common.fetch(options, 'memLevel', zlib.Z_DEFAULT_MEMLEVEL);
@@ -90,19 +88,8 @@ Session.prototype.processOutgoingMessage = function(message, callback) {
   };
 
   var onData = function(data) {
-    var tail  = data.slice(Math.max(data.length - 4, 0), data.length),
-        isEnd = (tail[0] === 0x00 && tail[1] === 0x00 && tail[2] === 0xff && tail[3] === 0xff);
-
-    if (isEnd) data = data.slice(0, data.length - 4);
-
     chunks.push(data);
     length += data.length;
-
-    if (isEnd) {
-      message.rsv1 = true;
-      message.data = common.concat(chunks, length);
-      return_(null, message);
-    }
   };
 
   var onError = function(error) {
@@ -111,9 +98,19 @@ Session.prototype.processOutgoingMessage = function(message, callback) {
 
   deflate.on('data', onData);
   deflate.on('error', onError);
-
   deflate.write(message.data);
-  if (VERSION[0] === 0 && VERSION[1] < 10) deflate.flush();
+
+  var onFlush = function() {
+    var data = common.concat(chunks, length);
+    message.data = data.slice(0, data.length - 4);
+    message.rsv1 = true;
+    return_(null, message);
+  };
+
+  if (deflate.params !== undefined)
+    deflate.flush(zlib.Z_SYNC_FLUSH, onFlush);
+  else
+    deflate.flush(onFlush);
 };
 
 Session.prototype.close = function() {
@@ -135,12 +132,29 @@ Session.prototype._getDeflate = function() {
   if (this._deflate) return this._deflate;
 
   var deflate = zlib.createDeflateRaw({
-    flush:      zlib.Z_SYNC_FLUSH,
     windowBits: this._ownWindowBits,
     level:      this._level,
     memLevel:   this._memLevel,
     strategy:   this._strategy
   });
+
+  var flush = deflate.flush;
+
+  // This monkey-patch is needed to make Node 0.10 produce optimal output.
+  // Without this it uses Z_FULL_FLUSH and effectively drops all its context
+  // state on every flush.
+
+  if (deflate._flushFlag !== undefined && deflate.params === undefined)
+    deflate.flush = function(callback) {
+      var ws = this._writableState;
+      if (ws.ended || ws.ending || ws.needDrain) {
+        flush.call(this, callback);
+      } else {
+        this._flushFlag = zlib.Z_SYNC_FLUSH;
+        this.write(new Buffer(0), '', callback);
+      }
+    };
+
   if (this._ownContextTakeover) this._deflate = deflate;
   return deflate;
 };

package.json

@@ -5,7 +5,7 @@
 , "keywords"        : ["websocket", "compression", "deflate"]
 , "license"         : "MIT"
 
-, "version"         : "0.1.2"
+, "version"         : "0.1.4"
 , "engines"         : {"node": ">=0.6.0"}
 , "main"            : "./lib/permessage_deflate"
 , "devDependencies" : {"jstest": ""}

spec/client_session_spec.js

@@ -9,7 +9,6 @@ test.describe("ClientSession", function() { with(this) {
 
     this.deflate  = zlibMock()
     this.inflate  = zlibMock()
-    this.flush    = zlib.Z_SYNC_FLUSH
     this.level    = zlib.Z_DEFAULT_LEVEL
     this.memLevel = zlib.Z_DEFAULT_MEMLEVEL
     this.strategy = zlib.Z_DEFAULT_STRATEGY
@@ -25,7 +24,7 @@ test.describe("ClientSession", function() { with(this) {
     this.stub(stream, "removeListener")
 
     this.stub(stream, "write")
-    this.stub(stream, "flush", function(cb) { if(cb) cb() });
+    this.stub(stream, "flush").yields([])
     this.stub(stream, "close").raises(new Error("unexpected close()"))
 
     return stream
@@ -71,7 +70,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 15 window bits for deflating outgoing messages", function() { with(this) {
         activate()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -102,7 +101,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses no context takeover and 15 window bits to deflate outgoing messages", function() { with(this) {
         activate()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
         expect(deflate, "close").exactly(2)
         processOutgoingMessage()
         processOutgoingMessage()
@@ -141,7 +140,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 8 window bits for deflating outgoing messages", function() { with(this) {
         activate()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 8, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 8, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -170,7 +169,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses no context takeover and 15 window bits for deflating outgoing messages", function() { with(this) {
         activate()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
         expect(deflate, "close").exactly(2)
         processOutgoingMessage()
         processOutgoingMessage()
@@ -192,7 +191,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 9 window bits for deflating outgoing messages", function() { with(this) {
         activate()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 9, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 9, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -215,7 +214,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 8 window bits for deflating outgoing messages", function() { with(this) {
         activate()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 8, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 8, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -310,7 +309,7 @@ test.describe("ClientSession", function() { with(this) {
 
     it("sets the level of the deflate stream", function() { with(this) {
       activate()
-      expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: zlib.Z_BEST_SPEED, memLevel: memLevel, strategy: strategy}).returns(deflate)
+      expect(zlib, "createDeflateRaw").given({windowBits: 15, level: zlib.Z_BEST_SPEED, memLevel: memLevel, strategy: strategy}).returns(deflate)
       processOutgoingMessage()
     }})
   }})
@@ -320,7 +319,7 @@ test.describe("ClientSession", function() { with(this) {
 
     it("sets the memLevel of the deflate stream", function() { with(this) {
       activate()
-      expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: 5, strategy: strategy}).returns(deflate)
+      expect(zlib, "createDeflateRaw").given({windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: 5, strategy: strategy}).returns(deflate)
       processOutgoingMessage()
     }})
   }})
@@ -330,7 +329,7 @@ test.describe("ClientSession", function() { with(this) {
 
     it("sets the strategy of the deflate stream", function() { with(this) {
       activate()
-      expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: memLevel, strategy: zlib.Z_FILTERED}).returns(deflate)
+      expect(zlib, "createDeflateRaw").given({windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: memLevel, strategy: zlib.Z_FILTERED}).returns(deflate)
       processOutgoingMessage()
     }})
   }})

spec/server_session_spec.js

@@ -2,14 +2,13 @@ var PermessageDeflate = require('../lib/permessage_deflate'),
     zlib = require('zlib'),
     test = require('jstest').Test
 
-test.describe("ClientSession", function() { with(this) {
+test.describe("ServerSession", function() { with(this) {
   before(function() { with(this) {
     this.ext      = PermessageDeflate.configure(options)
     this.session  = ext.createServerSession([offer])
 
     this.deflate  = zlibMock()
     this.inflate  = zlibMock()
-    this.flush    = zlib.Z_SYNC_FLUSH
     this.level    = zlib.Z_DEFAULT_LEVEL
     this.memLevel = zlib.Z_DEFAULT_MEMLEVEL
     this.strategy = zlib.Z_DEFAULT_STRATEGY
@@ -25,7 +24,7 @@ test.describe("ClientSession", function() { with(this) {
     this.stub(stream, "removeListener")
 
     this.stub(stream, "write")
-    this.stub(stream, "flush", function(cb) { if(cb) cb() });
+    this.stub(stream, "flush").yields([])
     this.stub(stream, "close").raises(new Error("unexpected close()"))
 
     return stream
@@ -62,7 +61,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 15 window bits for deflating outgoing messages", function() { with(this) {
         response()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -77,7 +76,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses no context takeover and 15 window bits for deflating outgoing messages", function() { with(this) {
         response()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
         expect(deflate, "close").exactly(2)
         processOutgoingMessage()
         processOutgoingMessage()
@@ -109,7 +108,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 13 window bits for deflating outgoing messages", function() { with(this) {
         response()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 13, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 13, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -172,7 +171,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses no context takeover and 15 window bits for deflating outgoing messages", function() { with(this) {
         response()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 15, level: level, memLevel: memLevel, strategy: strategy}).exactly(2).returning(deflate)
         expect(deflate, "close").exactly(2)
         processOutgoingMessage()
         processOutgoingMessage()
@@ -184,13 +183,13 @@ test.describe("ClientSession", function() { with(this) {
     define("options", {maxWindowBits: 12})
 
     describe("with an empty offer", function() { with(this) {
-      it("includes server_max_window_bits in the response", function() { with(this) {
-        assertEqual( {server_max_window_bits: 12}, response() )
+      it("does not include server_max_window_bits in the response", function() { with(this) {
+        assertEqual( {}, response() )
       }})
 
       it("uses context takeover and 12 window bits for deflating outgoing messages", function() { with(this) {
         response()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 12, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 12, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -205,7 +204,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 12 window bits for deflating outgoing messages", function() { with(this) {
         response()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 12, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 12, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -220,7 +219,7 @@ test.describe("ClientSession", function() { with(this) {
 
       it("uses context takeover and 11 window bits for deflating outgoing messages", function() { with(this) {
         response()
-        expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 11, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
+        expect(zlib, "createDeflateRaw").given({windowBits: 11, level: level, memLevel: memLevel, strategy: strategy}).exactly(1).returning(deflate)
         processOutgoingMessage()
         processOutgoingMessage()
       }})
@@ -312,7 +311,7 @@ test.describe("ClientSession", function() { with(this) {
 
     it("sets the level of the deflate stream", function() { with(this) {
       response()
-      expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: zlib.Z_BEST_SPEED, memLevel: memLevel, strategy: strategy}).returns(deflate)
+      expect(zlib, "createDeflateRaw").given({windowBits: 15, level: zlib.Z_BEST_SPEED, memLevel: memLevel, strategy: strategy}).returns(deflate)
       processOutgoingMessage()
     }})
   }})
@@ -322,7 +321,7 @@ test.describe("ClientSession", function() { with(this) {
 
     it("sets the memLevel of the deflate stream", function() { with(this) {
       response()
-      expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: 5, strategy: strategy}).returns(deflate)
+      expect(zlib, "createDeflateRaw").given({windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: 5, strategy: strategy}).returns(deflate)
       processOutgoingMessage()
     }})
   }})
@@ -332,7 +331,7 @@ test.describe("ClientSession", function() { with(this) {
 
     it("sets the strategy of the deflate stream", function() { with(this) {
       response()
-      expect(zlib, "createDeflateRaw").given({flush: flush, windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: memLevel, strategy: zlib.Z_FILTERED}).returns(deflate)
+      expect(zlib, "createDeflateRaw").given({windowBits: 15, level: zlib.Z_DEFAULT_LEVEL, memLevel: memLevel, strategy: zlib.Z_FILTERED}).returns(deflate)
       processOutgoingMessage()
     }})
   }})