set-headers-vs-response

Example Code

import { Elysia } from "elysia";
export default new Elysia().get("/", async ({ set }) => {
  set.headers["x-foo"] = "bar";
  return new Response("hi", {
    headers: {
      "x-foo": "baz",
    },
  });
});

Tests

Test	bun	node
test	🏃	🏃

test

bun

=== Test Execution ===
$ curl -s -D- "http://localhost:3000"
HTTP/1.1 200 OK
x-foo: baz, bar
content-type: text/plain;charset=utf-8
Date: Sun, 01 Jun 2025 06:23:47 GMT
Content-Length: 2

hi

=== Runtime Output ===
[runtime] Bun 1.2.15
Started development server: http://localhost:3000

node

=== Test Execution ===
$ curl -s -D- "http://localhost:3000"
HTTP/1.1 200 OK
x-foo: baz, bar
content-type: text/plain; charset=UTF-8
Content-Length: 2
Date: Sun, 01 Jun 2025 06:23:48 GMT
Connection: keep-alive
Keep-Alive: timeout=5

hi

=== Runtime Output ===
(node:28) ExperimentalWarning: Type Stripping is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
[runtime] Node v22.16.0
🦊 Elysia is running at :::3000