Certain redirect scenarios result in TypeError: immutable

[eliellis]

What version of Elysia is running?

1.2.10

What platform is your computer?

Darwin 24.1.0 arm64 arm

What steps can reproduce the bug?

Run the following:

import { Elysia } from "elysia";
import { node } from "@elysiajs/node";
import { cors } from "@elysiajs/cors";

const app = new Elysia({
  adapter: typeof Bun === "undefined" ? node() : undefined,
})
  .use(cors())
  .get("/home", () => {
    return "Home";
  })
  .onError(({ redirect }) => {
    return redirect("http://localhost:3000/home");
  })
  .onRequest(({ request, redirect }) => {
    if (new URL(request.url).pathname !== "/home") {
      return redirect("/home");
    }
  })
  .listen(3000);

const res = await fetch("http://localhost:3000/redirect-me", {
  redirect: "manual",
});

console.log("status", res.status);

await app.stop(true);

What is the expected behavior?

The above should print status 302. Running the same sample with bun run does print status 302.

What do you see instead?

node:internal/deps/undici/undici:8651
        throw new TypeError("immutable");
              ^

TypeError: immutable
    at appendHeader (node:internal/deps/undici/undici:8651:15)
    at _Headers.append (node:internal/deps/undici/undici:8854:16)
    at mergeResponseWithSetHeaders (file:///Users/eli/code/elysia-node-redirect-issue/node_modules/elysia/dist/adapter/web-standard/handler.mjs:185:24)
    at mapResponse (file:///Users/eli/code/elysia-node-redirect-issue/node_modules/@elysiajs/node/dist/index.mjs:240:18)
    at Elysia.eval [as handleError] (eval at composeErrorHandler (file:///Users/eli/code/elysia-node-redirect-issue/node_modules/elysia/dist/compose.mjs:1435:10), <anonymous>:19:53)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)

Node.js v23.6.1

Additional information

No response

Have you try removing the node_modules and bun.lockb and try again yet?

yes

[SaltyAom]

The redirect value is expected to be a full URL due to the Web Standard redirect.
We don't support partial URLs at the moment which is reported under #25.

Moving the issue all together with #25