Node does not throw on non standard method

[mikicho]

Version

v22.16.0

Platform

Linux Desktop 5.15.167.4-microsoft-standard-WSL2 #1 SMP Tue Nov 5 00:21:55 UTC 2024 x86_64 GNU/Linux

Subsystem

Debian

What steps will reproduce the bug?

import http from 'http';

const server = http.createServer((req, res) => {
  if (req.method === 'LIST' && req.url === '/list') {
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ message: 'List request received' }));
  } else {
    res.writeHead(404, { 'Content-Type': 'text/plain' });
    res.end('Not Found');
  }
});

server.listen(3000, () => {
  console.log('Server is listening on port 3000');
});
  

const options = {
  hostname: 'localhost',
  port: 3000,
  path: '/list',
  method: 'LIST',
};

const req = http.request(options, (res) => {
  let data = '';
  res.on('data', (chunk) => {
    data += chunk;
  });

  res.on('end', () => {
    console.log('Response:', data); //data is empty!
  });
});

req.on('error', (error) => {
  console.error('Error:', error);
});

req.end();

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

Every time

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

Node should throw/emit error because the LIST method is not supported.

What do you see instead?

The "end' response event is emitted even though the request never reaches the server.

Additional information

The llhttp parser returns an error:
NODE_DEBUG=* ..

HTTP 183038: parse error [Error: Parse Error: Invalid method encountered] {
  bytesParsed: 2,
  code: 'HPE_INVALID_METHOD',
  reason: 'Invalid method encountered',
  rawPacket: <Buffer 4c 49 ...>
}

[Annaick]

The server already detects and reports the invalid HTTP method (LIST). Users can handle it today with:

server.on('clientError', (err, socket) => {
  if (err.code === 'HPE_INVALID_METHOD') {
    socket.end(
      'HTTP/1.1 400 Bad Request\r\n' +
      'Connection: close\r\n\r\n' +
      'Invalid HTTP method\r\n'
    );
  } else {
    // delegate other parser errors
    socket.destroy(err);
  }
});

we could update the doc http.md with example to show users how to handle invalid method

[Annaick]

We could also implement a default listener if none is provided to return a request error. what would you think?

[jasnell]

This is not an error condition in the runtime. Whether to support non-standard methods or not is up to the application, not the runtime. Per the http spec, http methods do not need to be standardized they just need to match a particular pattern and it's better for extensibility for node.js to just ignore/passthrough non-standard values.

[Annaick]

@jasnell You're right. But then how could we implement custom method if the node http parser doesn't allow arbitrary value?

[mikicho]

Oh.... so the node sends the request, but the default behavior is a 400 error with an empty body?

it's better for extensibility for node.js to just ignore/passthrough non-standard values

@jasnell, so doesn't the node server just need to accept the request?

[ericmorand]

@jasnell

Whether to support non-standard methods or not is up to the application, not the runtime

Absolutely. An in addition to @Annaick question:

• Why is the runtime returning a 400 response instead of just passing the request as usual if, as you mention, "Whether to support non-standard methods or not is up to the application"?
• Why is the runtime making an exception for the PURGE method which is not standard?