[Feat]: Better DX for Abort events

Duplicates

• I have searched the existing issues

Latest version

• I have tested the latest version

Current behavior 😯

When the request is aborted, the abort event is not fired within server API route.

Example server API route

import type { APIEvent } from "@solidjs/start/server";
export async function GET(event: APIEvent) {

    event.request.signal.addEventListener("abort", () => {
        console.log('abort detected')
    })

    let i = 0;
    while (i < 20) {
        console.log('looping', i++, event.request.signal.aborted)
        await new Promise(resolve => setTimeout(resolve, 1000))
    }

    return new Response(null, { status: 200 })
}

Example browser triggers

<button
onClick={() => {
  controller = new AbortController();
  fetch("/api/test", {
    method: "GET",
    signal: new AbortController().signal,
  })
    .then((response) => {
      console.log("response", response);
    })
    .catch((error) => {
      console.log("error", error);
    });
}}
>
Call
</button>
<button
onClick={() => {
  console.log("controller", controller);
  controller?.abort("I am aborting this request");
  controller = undefined;
}}
>
Abort
</button>

Expected behavior 🤔

When user cancel the request in browser, the abort event should be fired.

Steps to reproduce 🕹

Steps:

1. Create an API route
2. Add abort listener inside the API route
3. In the browser, fetch & abort
4. Notice that the abort event is not fired inside the API route

Context 🔦

I'm building an AI chat app that streams the token from the AI provider back to the user.
Currently when the user clicks aborting the request, the api route could not detect that and keep streaming from the AI provider, wasting token.

Not sure if related but Next.js used to have a similar issue https://github.com/vercel/next.js/discussions/48682

Your environment 🌎

Linux denpa 6.12.10-arch1-1 #1 SMP PREEMPT_DYNAMIC Sat, 18 Jan 2025 02:26:57 +0000 x86_64 GNU/Linux

bun --version
1.2.0

node --version
v23.4.0

"dependencies": {
    "@solidjs/meta": "^0.29.4",
    "@solidjs/router": "^0.15.0",
    "@solidjs/start": "^1.0.11",
    "solid-js": "^1.9.2",
    "vinxi": "^0.4.3"
  },

Start by tracing how a server API route receives event.request and its AbortSignal, then compare that path with the browser fetch and AbortController reproduction. Verify whether cancellation reaches the server while the route is waiting and streaming; done means the route's abort listener fires when the browser cancels the request and the reproduction no longer continues unnecessary work.