From 2c22a16309aaeef8ccaf1f858d64793020e588bc Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Tue, 25 Aug 2015 16:41:21 +0300
Subject: [PATCH 01/10] added before-flushing-head event to
 _http_server.ServerResponse.writeHead

---
 lib/_http_server.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/_http_server.js b/lib/_http_server.js
index f337480ec2dd75..0de14df2cb92cb 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -160,6 +160,8 @@ ServerResponse.prototype._implicitHeader = function() {
 ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
   var headers;
 
+  this.emit("before-flushing-head");
+
   if (typeof reason === 'string') {
     // writeHead(statusCode, reasonPhrase[, headers])
     this.statusMessage = reason;

From 5c774e0fb684acf74ea59e661739bab2083c46e3 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Wed, 26 Aug 2015 11:50:00 +0300
Subject: [PATCH 02/10] added docs for before-flushing-head

---
 doc/api/http.markdown | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/doc/api/http.markdown b/doc/api/http.markdown
index 8ab9877a2e536b..5dd0964e71e1f1 100644
--- a/doc/api/http.markdown
+++ b/doc/api/http.markdown
@@ -640,6 +640,14 @@ passed as the second parameter to the `'request'` event.
 The response implements the [Writable Stream][] interface. This is an
 [`EventEmitter`][] with the following events:
 
+### Event: 'before-flushing-head'
+
+`function () {}`
+
+Indicates that the server is about to flush the HTTP headers to the underlying 
+socket. This event can be used for measuring time to first byte or customizing 
+the response headers.
+
 ### Event: 'close'
 
 `function () { }`

From a58a58e8ad6e053426ea6483095f87c9b2417ac0 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Wed, 26 Aug 2015 12:28:57 +0300
Subject: [PATCH 03/10] added test for before-flush-head event of HTTP response

---
 .../test-http-before-flush-head-event.js      | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 test/parallel/test-http-before-flush-head-event.js

diff --git a/test/parallel/test-http-before-flush-head-event.js b/test/parallel/test-http-before-flush-head-event.js
new file mode 100644
index 00000000000000..145ddba2c1530a
--- /dev/null
+++ b/test/parallel/test-http-before-flush-head-event.js
@@ -0,0 +1,40 @@
+'use strict';
+//var common = require('../common');
+var common = {};
+common.PORT = 1234;
+var assert = require('assert');
+var http = require('http');
+
+var testResBody = 'other stuff!\n';
+
+var server = http.createServer(function(req, res) {
+  res.on('before-flush-head', function() {
+    res.setHeader('Flush-Head', 'event-was-called');
+  })
+  res.writeHead(200, {
+    'Content-Type': 'text/plain'
+  });
+  res.end(testResBody);
+});
+server.listen(common.PORT);
+
+
+server.addListener('listening', function() {
+  var options = {
+    port: common.PORT,
+    path: '/',
+    method: 'GET'
+  };
+  var req = http.request(options, function(res) {
+    assert.ok('flush-head' in res.headers,
+              'Response headers didn\'t contain the flush-head header, indicating the before-flush-head event was not called or did not allow adding headers.');
+    assert.ok(res.headers['flush-head'] === 'event-was-called',
+              'Response headers didn\'t contain the flush-head header with value event-was-called, indicating the before-flush-head event was not called or did not allow adding headers.');
+    res.addListener('end', function() {
+      server.close();
+      process.exit();
+    });
+    res.resume();
+  });
+  req.end();
+});

From ce6d84962b90579c4473b21b7ee770b3463d7bfe Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Thu, 27 Aug 2015 14:36:42 +0300
Subject: [PATCH 04/10] extended the before-flushing-head event to enable
 customizing the response code, response message nad headers

---
 doc/api/http.markdown                         | 11 ++++++--
 lib/_http_server.js                           | 25 +++++++++++--------
 .../test-http-before-flush-head-event.js      | 14 +++++++----
 3 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/doc/api/http.markdown b/doc/api/http.markdown
index 5dd0964e71e1f1..aee7ec27add28f 100644
--- a/doc/api/http.markdown
+++ b/doc/api/http.markdown
@@ -642,11 +642,18 @@ The response implements the [Writable Stream][] interface. This is an
 
 ### Event: 'before-flushing-head'
 
-`function () {}`
+`function (messageHead) {}`
 
 Indicates that the server is about to flush the HTTP headers to the underlying 
 socket. This event can be used for measuring time to first byte or customizing 
-the response headers.
+the response headers and status code.
+
+The `messageHead` parameter allows overriding the http response code, message and headers. 
+It includes
+
+* `responseCode` {Number}
+* `responseMessage` {String}
+* `headers` {Object}
 
 ### Event: 'close'
 
diff --git a/lib/_http_server.js b/lib/_http_server.js
index 0de14df2cb92cb..0e4114120aa2f6 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -160,18 +160,15 @@ ServerResponse.prototype._implicitHeader = function() {
 ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
   var headers;
 
-  this.emit("before-flushing-head");
+  // writeHead(statusCode, reasonPhrase[, headers])
+  var args = {statusCode: statusCode, statusMessage: reason, headers: obj};
 
-  if (typeof reason === 'string') {
-    // writeHead(statusCode, reasonPhrase[, headers])
-    this.statusMessage = reason;
-  } else {
+  if (!(typeof args.statusMessage === 'string')) {
     // writeHead(statusCode[, headers])
-    this.statusMessage =
+    args.statusMessage =
         this.statusMessage || STATUS_CODES[statusCode] || 'unknown';
-    obj = reason;
+    args.headers = reason;
   }
-  this.statusCode = statusCode;
 
   if (this._headers) {
     // Slow-case: when progressive API and header fields are passed.
@@ -183,13 +180,19 @@ ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
       }
     }
     // only progressive api is used
-    headers = this._renderHeaders();
+    args.headers = this._renderHeaders();
   } else {
     // only writeHead() called
-    headers = obj;
+    args.headers = obj || {};
   }
 
-  var statusLine = 'HTTP/1.1 ' + statusCode.toString() + ' ' +
+  this.emit("before-flushing-head", args);
+
+  this.statusMessage = args.statusMessage;
+  this.statusCode = args.statusCode;
+  headers = args.headers;
+
+  var statusLine = 'HTTP/1.1 ' + this.statusCode.toString() + ' ' +
                    this.statusMessage + CRLF;
 
   if (statusCode === 204 || statusCode === 304 ||
diff --git a/test/parallel/test-http-before-flush-head-event.js b/test/parallel/test-http-before-flush-head-event.js
index 145ddba2c1530a..dcca7ccf818c71 100644
--- a/test/parallel/test-http-before-flush-head-event.js
+++ b/test/parallel/test-http-before-flush-head-event.js
@@ -1,15 +1,15 @@
 'use strict';
-//var common = require('../common');
-var common = {};
-common.PORT = 1234;
+var common = require('../common');
 var assert = require('assert');
 var http = require('http');
 
 var testResBody = 'other stuff!\n';
 
 var server = http.createServer(function(req, res) {
-  res.on('before-flush-head', function() {
-    res.setHeader('Flush-Head', 'event-was-called');
+  res.on('before-flushing-head', function(args) {
+    args.statusCode = 201;
+    args.statusMessage = "changed to show we can";
+    args.headers["Flush-Head"] = 'event-was-called'; 
   })
   res.writeHead(200, {
     'Content-Type': 'text/plain'
@@ -26,6 +26,10 @@ server.addListener('listening', function() {
     method: 'GET'
   };
   var req = http.request(options, function(res) {
+    assert.ok(res.statusCode === 201,
+              'Response status code was not overridden from 200 to 201.');
+    assert.ok(res.statusMessage === 'changed to show we can', 
+              'Response status message was not overridden.');
     assert.ok('flush-head' in res.headers,
               'Response headers didn\'t contain the flush-head header, indicating the before-flush-head event was not called or did not allow adding headers.');
     assert.ok(res.headers['flush-head'] === 'event-was-called',

From 335db4c310fed78e54c09905295bdac8d5bf3aa9 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Tue, 17 Nov 2015 00:02:02 +0200
Subject: [PATCH 05/10] renamed before-flushing-head to beforeFlushingHead

---
 doc/api/http.markdown                              | 2 +-
 lib/_http_server.js                                | 2 +-
 test/parallel/test-http-before-flush-head-event.js | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/doc/api/http.markdown b/doc/api/http.markdown
index aee7ec27add28f..53b351cbb75834 100644
--- a/doc/api/http.markdown
+++ b/doc/api/http.markdown
@@ -640,7 +640,7 @@ passed as the second parameter to the `'request'` event.
 The response implements the [Writable Stream][] interface. This is an
 [`EventEmitter`][] with the following events:
 
-### Event: 'before-flushing-head'
+### Event: 'beforeFlushingHead'
 
 `function (messageHead) {}`
 
diff --git a/lib/_http_server.js b/lib/_http_server.js
index 0e4114120aa2f6..f251d8b3b587c2 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -186,7 +186,7 @@ ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
     args.headers = obj || {};
   }
 
-  this.emit("before-flushing-head", args);
+  this.emit("beforeFlushingHead", args);
 
   this.statusMessage = args.statusMessage;
   this.statusCode = args.statusCode;
diff --git a/test/parallel/test-http-before-flush-head-event.js b/test/parallel/test-http-before-flush-head-event.js
index dcca7ccf818c71..4bc7149abbff1e 100644
--- a/test/parallel/test-http-before-flush-head-event.js
+++ b/test/parallel/test-http-before-flush-head-event.js
@@ -6,7 +6,7 @@ var http = require('http');
 var testResBody = 'other stuff!\n';
 
 var server = http.createServer(function(req, res) {
-  res.on('before-flushing-head', function(args) {
+  res.on('beforeFlushingHead', function(args) {
     args.statusCode = 201;
     args.statusMessage = "changed to show we can";
     args.headers["Flush-Head"] = 'event-was-called'; 
@@ -31,9 +31,9 @@ server.addListener('listening', function() {
     assert.ok(res.statusMessage === 'changed to show we can', 
               'Response status message was not overridden.');
     assert.ok('flush-head' in res.headers,
-              'Response headers didn\'t contain the flush-head header, indicating the before-flush-head event was not called or did not allow adding headers.');
+              'Response headers didn\'t contain the flush-head header, indicating the beforeFlushingHead event was not called or did not allow adding headers.');
     assert.ok(res.headers['flush-head'] === 'event-was-called',
-              'Response headers didn\'t contain the flush-head header with value event-was-called, indicating the before-flush-head event was not called or did not allow adding headers.');
+              'Response headers didn\'t contain the flush-head header with value event-was-called, indicating the beforeFlushingHead event was not called or did not allow adding headers.');
     res.addListener('end', function() {
       server.close();
       process.exit();

From 76620e4a612828ed9577c360c47cea337d192880 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Tue, 8 Dec 2015 11:15:26 +0200
Subject: [PATCH 06/10] code style issues

---
 .../test-http-before-flush-head-event.js      | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/test/parallel/test-http-before-flush-head-event.js b/test/parallel/test-http-before-flush-head-event.js
index 4bc7149abbff1e..aad0fbc2d697b8 100644
--- a/test/parallel/test-http-before-flush-head-event.js
+++ b/test/parallel/test-http-before-flush-head-event.js
@@ -1,15 +1,15 @@
 'use strict';
-var common = require('../common');
-var assert = require('assert');
-var http = require('http');
+const common = require('../common'),
+  assert = require('assert'),
+  http = require('http');
 
 var testResBody = 'other stuff!\n';
 
 var server = http.createServer(function(req, res) {
   res.on('beforeFlushingHead', function(args) {
     args.statusCode = 201;
-    args.statusMessage = "changed to show we can";
-    args.headers["Flush-Head"] = 'event-was-called'; 
+    args.statusMessage = 'changed to show we can';
+    args.headers['Flush-Head'] = 'event-was-called';
   })
   res.writeHead(200, {
     'Content-Type': 'text/plain'
@@ -31,9 +31,14 @@ server.addListener('listening', function() {
     assert.ok(res.statusMessage === 'changed to show we can', 
               'Response status message was not overridden.');
     assert.ok('flush-head' in res.headers,
-              'Response headers didn\'t contain the flush-head header, indicating the beforeFlushingHead event was not called or did not allow adding headers.');
+              'Response headers didn\'t contain the flush-head header, ' +
+                'indicating the beforeFlushingHead event was not called or ' +
+                'did not allow adding headers.');
     assert.ok(res.headers['flush-head'] === 'event-was-called',
-              'Response headers didn\'t contain the flush-head header with value event-was-called, indicating the beforeFlushingHead event was not called or did not allow adding headers.');
+              'Response headers didn\'t contain the flush-head header ' +
+                'with value event-was-called, indicating the ' +
+                'beforeFlushingHead event was not called or did not allow ' +
+                'adding headers.');
     res.addListener('end', function() {
       server.close();
       process.exit();

From df3f243c67f207551a70537558430bb63709d478 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Tue, 8 Dec 2015 11:15:59 +0200
Subject: [PATCH 07/10] fixed broken test parallel/test-http-write-head.js

---
 lib/_http_server.js | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/lib/_http_server.js b/lib/_http_server.js
index f251d8b3b587c2..900fec761eb778 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -163,20 +163,22 @@ ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
   // writeHead(statusCode, reasonPhrase[, headers])
   var args = {statusCode: statusCode, statusMessage: reason, headers: obj};
 
-  if (!(typeof args.statusMessage === 'string')) {
+  if (typeof args.statusMessage !== 'string') {
     // writeHead(statusCode[, headers])
     args.statusMessage =
         this.statusMessage || STATUS_CODES[statusCode] || 'unknown';
     args.headers = reason;
   }
 
+  args.headers = args.headers || {};
+
   if (this._headers) {
     // Slow-case: when progressive API and header fields are passed.
-    if (obj) {
-      var keys = Object.keys(obj);
+    if (args.headers) {
+      var keys = Object.keys(args.headers);
       for (var i = 0; i < keys.length; i++) {
         var k = keys[i];
-        if (k) this.setHeader(k, obj[k]);
+        if (k) this.setHeader(k, args.headers[k]);
       }
     }
     // only progressive api is used

From 118a0a8e63f531451f551129c4b5da84da251786 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Tue, 8 Dec 2015 11:29:33 +0200
Subject: [PATCH 08/10] fixed bug in handling the case when _header is not set.

---
 lib/_http_server.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/_http_server.js b/lib/_http_server.js
index 900fec761eb778..88ee3372098e2f 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -185,7 +185,7 @@ ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
     args.headers = this._renderHeaders();
   } else {
     // only writeHead() called
-    args.headers = obj || {};
+
   }
 
   this.emit("beforeFlushingHead", args);

From 84ce98ce0d8edb7a8fe80e3ab5c34a69aa8a3c33 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Tue, 8 Dec 2015 11:32:34 +0200
Subject: [PATCH 09/10] js lint - code formatting, etc.

---
 lib/_http_server.js                                | 5 +----
 test/parallel/test-http-before-flush-head-event.js | 4 ++--
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/lib/_http_server.js b/lib/_http_server.js
index 88ee3372098e2f..a3e03846348780 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -183,12 +183,9 @@ ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
     }
     // only progressive api is used
     args.headers = this._renderHeaders();
-  } else {
-    // only writeHead() called
-
   }
 
-  this.emit("beforeFlushingHead", args);
+  this.emit('beforeFlushingHead', args);
 
   this.statusMessage = args.statusMessage;
   this.statusCode = args.statusCode;
diff --git a/test/parallel/test-http-before-flush-head-event.js b/test/parallel/test-http-before-flush-head-event.js
index aad0fbc2d697b8..e5e11ab8fd9ea4 100644
--- a/test/parallel/test-http-before-flush-head-event.js
+++ b/test/parallel/test-http-before-flush-head-event.js
@@ -10,7 +10,7 @@ var server = http.createServer(function(req, res) {
     args.statusCode = 201;
     args.statusMessage = 'changed to show we can';
     args.headers['Flush-Head'] = 'event-was-called';
-  })
+  });
   res.writeHead(200, {
     'Content-Type': 'text/plain'
   });
@@ -28,7 +28,7 @@ server.addListener('listening', function() {
   var req = http.request(options, function(res) {
     assert.ok(res.statusCode === 201,
               'Response status code was not overridden from 200 to 201.');
-    assert.ok(res.statusMessage === 'changed to show we can', 
+    assert.ok(res.statusMessage === 'changed to show we can',
               'Response status message was not overridden.');
     assert.ok('flush-head' in res.headers,
               'Response headers didn\'t contain the flush-head header, ' +

From 58bd0b3ee917d17fcccc78c12e17cfa9a6ca59a2 Mon Sep 17 00:00:00 2001
From: "yoav@wix.com" <yoav@wix.com>
Date: Tue, 8 Dec 2015 12:15:10 +0200
Subject: [PATCH 10/10] js lint - code formatting, etc.

---
 doc/api/http.markdown | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/doc/api/http.markdown b/doc/api/http.markdown
index 53b351cbb75834..e92fd38b406707 100644
--- a/doc/api/http.markdown
+++ b/doc/api/http.markdown
@@ -653,7 +653,12 @@ It includes
 
 * `responseCode` {Number}
 * `responseMessage` {String}
-* `headers` {Object}
+* `headers` {Object|Array}
+
+The headers member will be either an object of the form
+`{header-names: header value}`
+or an array of the form
+`[['header-name', 'header-value'] ...]`
 
 ### Event: 'close'