PATCH method doesn't work with fetch

[fxdave]

Version

v21.5.0

Platform

Linux dbiro-pc 6.6.7-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 14 Dec 2023 03:45:42 +0000 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

1. Create a server with an endpoint that responds with a json
2. Create a client with this:

fetch("http://localhost:8080/endpoint",{
  body: '{"segments":["put"],"argument":{}}',
  method: 'put',
  headers: { 'Content-Type': 'application/json', Accept: 'application/json' }
})

3. The response.json() will throw an error because the body is empty

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

always

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

It should get the json

What do you see instead?

It returns Bad Request error and the body is empty

Additional information

GET, DELETE, POST, PUT work. Only PATCH has this problem. Using the node-fetch instead of the built-in version solves the problem.

[aduh95]

1. Create a server with an endpoint that responds with a json

I'd be helpful if your code snippet could include one, so we can run a repro and confirm the issue.

[fxdave]

@aduh95
I created a branch that uses nodejs's fetch.

git clone https://github.com/fxdave/cuple.git
cd cuple
git checkout use-nodejs-fetch
npm i
npm run test

[aduh95]

A minimal repro should not include downloading any code from the internet, so no GitHub repo, no npm deps. Here's what I can do from the issue description:

require("node:http")
  .createServer((_, res) => {
    res.setHeader("Content-Type", "application/json");
    res.end("{}");
  })
  .unref()
  .listen(8080, () => {
    fetch("http://localhost:8080/endpoint", {
      body: '{"segments":["put"],"argument":{}}',
      method: "put",
      headers: {
        "Content-Type": "application/json",
        Accept: "application/json",
      },
    }).then(res => res.json()).then(console.log, console.error);
  });

Running the above code, I don't see any error.

[fxdave]

@aduh95 Thanks for the example! Please replace put with patch and you will see the error:

[aduh95]

FWIW trying with the following code:

require("node:http")
  .createServer((req, res) => {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', '*');
    res.setHeader('Access-Control-Allow-Headers', '*');
    if (req.method === 'OPTIONS') {
      res.writeHead(204);
      res.end()
      return
    }
    res.setHeader("Content-Type", "application/json");
    res.end("{}");
  })
  .listen(8080, () => {
    fetch("http://localhost:8080/endpoint", {
      body: '{"segments":["put"],"argument":{}}',
      method: "patch",
      headers: {
        "Content-Type": "application/json",
        Accept: "application/json",
      },
    }).then(res => res.json()).then(console.log, console.error);
  });                                              

Then visiting about:blank and pasting the fetch call from the browser DevTools console fails on Chromium and Firefox, but works on Safari. Maybe it's an undefined behavior in the HTML spec? /cc @nodejs/undici

[KhafraDev]

patch isn't normalized to PATCH as per the spec. Replacing it fixes the issue.

[KhafraDev]

https://fetch.spec.whatwg.org/#example-normalization

[fxdave]

Oh interesting! Thanks @aduh95, @KhafraDev !

[Aissaoui-Saber]

try to uppercase patch to PATCH