Bun with Astro on SSR issue with endpoints when running with > bunx --bun astro dev

[copongcopong]

What version of Bun is running?

1.1.30

What platform is your computer?

aarch64

What steps can reproduce the bug?

> bun create astro ... let it create the astro stack

> bunx astro add vercel ... add this for SSR adapter

create test endpoint in /src/pages/[...slug].ts

import type { APIRoute } from "astro"

export const GET: APIRoute = (ctx) => {
  const { slug } = ctx.params;
  return new Response(
    JSON.stringify({
      greeting: 'Hello',
      slug
    }),
  )
}

> bunx astro dev ... visit http://localhost:4321/slug/slug shows page with JSON
> bunx --bun astro dev ... visit http://localhost:4321/slug/slug triggers download (headers content-type: application/octet-stream)

What is the expected behavior?

> bunx astro dev and > bunx --bun astro dev both should show page

What do you see instead?

> bunx --bun astro dev shows headers as content-type: application/octet-stream triggering a page download

Additional information

{
  "name": "test-endpoint",
  "type": "module",
  "version": "0.0.1",
  "scripts": {
    "dev": "astro dev",
    "start": "astro dev",
    "build": "astro check && astro build",
    "preview": "astro preview",
    "astro": "astro"
  },
  "dependencies": {
    "@astrojs/check": "^0.9.3",
    "@astrojs/vercel": "^7.8.1",
    "astro": "^4.15.9",
    "typescript": "^5.6.2"
  }
}