From 87279c08aa46d178fe6f2e235d2345f17d6b5a37 Mon Sep 17 00:00:00 2001
From: "Tito D. Kesumo Siregar" <tito.siregar@bukalapak.com>
Date: Thu, 20 May 2021 11:23:33 +0700
Subject: [PATCH] Support proper 205 responses using res.send

closes #4592
closes #4596
---
 History.md       |  5 +++++
 lib/response.js  |  7 +++++++
 test/res.send.js | 16 ++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/History.md b/History.md
index 9f3f876512..fbe0126907 100644
--- a/History.md
+++ b/History.md
@@ -1,3 +1,8 @@
+unreleased
+==========
+
+  * Support proper 205 responses using `res.send`
+
 4.17.3 / 2022-02-16
 ===================
 
diff --git a/lib/response.js b/lib/response.js
index ccf8d91b2c..9cf3d52be5 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -213,6 +213,13 @@ res.send = function send(body) {
     chunk = '';
   }
 
+  // alter headers for 205
+  if (this.statusCode === 205) {
+    this.set('Content-Length', '0')
+    this.removeHeader('Transfer-Encoding')
+    chunk = ''
+  }
+
   if (req.method === 'HEAD') {
     // skip body for HEAD
     this.end();
diff --git a/test/res.send.js b/test/res.send.js
index 6ba5542288..c92568db6a 100644
--- a/test/res.send.js
+++ b/test/res.send.js
@@ -283,6 +283,22 @@ describe('res', function(){
     })
   })
 
+  describe('when .statusCode is 205', function () {
+    it('should strip Transfer-Encoding field and body, set Content-Length', function (done) {
+      var app = express()
+
+      app.use(function (req, res) {
+        res.status(205).set('Transfer-Encoding', 'chunked').send('foo')
+      })
+
+      request(app)
+        .get('/')
+        .expect(utils.shouldNotHaveHeader('Transfer-Encoding'))
+        .expect('Content-Length', '0')
+        .expect(205, '', done)
+    })
+  })
+
   describe('when .statusCode is 304', function(){
     it('should strip Content-* fields, Transfer-Encoding field, and body', function(done){
       var app = express();