Node.js: returning "this" from writeHead() to allow chaining.

In Node.js version 11.10.0 and later, the writeHead() function returns "this".

src/nodejs/unit-http/http_server.js

@@ -195,6 +195,8 @@ function writeHead(statusCode, reason, obj) {
             }
         }
     }
+
+    return this;
 };
 
 /*

test/node/404/app.js

@@ -3,6 +3,5 @@
 var fs = require('fs');
 
 require('unit-http').createServer(function (req, res) {
-    res.writeHead(404, {});
+    res.writeHead(404, {}).end(fs.readFileSync('404.html'));
-    res.end(fs.readFileSync('404.html'));
 }).listen(7080);

test/node/basic/app.js

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 
 require('unit-http').createServer(function (req, res) {
-    res.writeHead(200, {'Content-Length': 12, 'Content-Type': 'text/plain'});
+    res.writeHead(200, {'Content-Length': 12, 'Content-Type': 'text/plain'})
-    res.end('Hello World\n');
+       .end('Hello World\n');
 }).listen(7080);

test/node/double_end/app.js

@@ -1,6 +1,5 @@
 #!/usr/bin/env node
 
 require('unit-http').createServer(function (req, res) {
-    res.end();
+    res.end().end();
-    res.end();
 }).listen(7080);

test/node/mirror/app.js

@@ -6,7 +6,7 @@ require('unit-http').createServer(function (req, res) {
         body += chunk.toString();
     });
     req.on('end', () => {
-        res.writeHead(200, {'Content-Length': Buffer.byteLength(body)});
+        res.writeHead(200, {'Content-Length': Buffer.byteLength(body)})
-        res.end(body);
+           .end(body);
     });
 }).listen(7080);

test/node/promise_handler/app.js

@@ -6,8 +6,7 @@ require('unit-http').createServer(function (req, res) {
     res.end();
 
     if (req.headers['x-write-call']) {
-        res.writeHead(200, {'Content-Type': 'text/plain'});
+        res.writeHead(200, {'Content-Type': 'text/plain'}).write('blah');
-        res.write('blah');
     }
 
     Promise.resolve().then(() => {

test/node/status_message/app.js

@@ -1,6 +1,5 @@
 #!/usr/bin/env node
 
 require('unit-http').createServer(function (req, res) {
-    res.writeHead(200, 'blah', {'Content-Type': 'text/plain'});
+    res.writeHead(200, 'blah', {'Content-Type': 'text/plain'}).end();
-    res.end();
 }).listen(7080);

test/node/variables/app.js

@@ -14,7 +14,6 @@ require('unit-http').createServer(function (req, res) {
         res.setHeader('Content-Type', req.headers['content-type']);
         res.setHeader('Custom-Header', req.headers['custom-header']);
         res.setHeader('Http-Host', req.headers['host']);
-        res.writeHead(200, {});
+        res.writeHead(200, {}).end(body);
-        res.end(body);
     });
 }).listen(7080);

test/node/write_before_write_head/app.js

@@ -2,6 +2,5 @@
 
 require('unit-http').createServer(function (req, res) {
     res.write('blah');
-    res.writeHead(200, {'Content-Type': 'text/plain'});
+    res.writeHead(200, {'Content-Type': 'text/plain'}).end();
-    res.end();
 }).listen(7080);

test/node/write_buffer/app.js

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 
 require('unit-http').createServer(function (req, res) {
-    res.writeHead(200, {'Content-Type': 'text/plain'});
+    res.writeHead(200, {'Content-Type': 'text/plain'})
-    res.end(new Buffer([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]));
+       .end(new Buffer([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]));
 }).listen(7080);

test/node/write_return/app.js

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 
 require('unit-http').createServer(function (req, res) {
-    res.writeHead(200, {'Content-Type': 'text/plain'});
+    res.writeHead(200, {'Content-Type': 'text/plain'})
-    res.end(res.write('body').toString());
+       .end(res.write('body').toString());
 }).listen(7080);