http.ServerResponse#strictContentLength = true is broken

[zefir-git]

Version

v22.13.0

Platform

Linux razer 6.13.6-200.fc41.x86_64 #1 SMP PREEMPT_DYNAMIC Fri Mar  7 21:33:48 UTC 2025 x86_64 GNU/Linux

Subsystem

http

What steps will reproduce the bug?

1. Use following code

   import http from "node:http";
   http.createServer((req, res) => {
       res.strictContentLength = true;
       res.setHeader("content-length", "5");
       res.end("12345");
   }).listen(3000);

2. Send any HTTP request to the server on port 3000

How often does it reproduce? Is there a required condition?

Always.

What is the expected behavior? Why is that the expected behavior?

Should not throw error.

What do you see instead?

Error [ERR_HTTP_CONTENT_LENGTH_MISMATCH]: Response body's content-length of 5 byte(s) does not match the content-length of 5 byte(s) set in header

node:_http_outgoing:1129
    throw new ERR_HTTP_CONTENT_LENGTH_MISMATCH(this[kBytesWritten], this._contentLength);
    ^

Error [ERR_HTTP_CONTENT_LENGTH_MISMATCH]: Response body's content-length of 5 byte(s) does not match the content-length of 5 byte(s) set in header
    at ServerResponse.end (node:_http_outgoing:1129:11)
    at Server.<anonymous> (file:///home/zefir/Projects/web-ts/test/test.js:5:9)
    at Server.emit (node:events:524:28)
    at parserOnIncoming (node:_http_server:1153:12)
    at HTTPParser.parserOnHeadersComplete (node:_http_common:117:17) {
  code: 'ERR_HTTP_CONTENT_LENGTH_MISMATCH'
}

Node.js v22.13.0

Additional information

No response

[marco-ippolito]

The issue is that you are passing the content-length value as a string, and its not being converted to number.
Opened a PR to fix

[zefir-git]

Thanks. When setting headers with Headers (e.g. ServerResponse#setHeaders(Headers)) it’s impossible not to have the value as string.