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Content-Length header missing when Content-Type present

See original GitHub issue

It appears that if the Content-Type header is present, Content-Length is not included in the response.

Example:

import { Hono } from "hono";

const app = new Hono();

app.head(
  "/test1",
  () =>
    new Response(null, {
      headers: {
        "content-length": "987654321",
      },
    })
);

app.head(
  "/test2",
  () =>
    new Response(null, {
      headers: {
        "content-type": "application/json",
        "content-length": "987654321",
      },
    })
);

export default app;

➤ curl --head http://0.0.0.0:8787/test1
HTTP/1.1 200 OK
date: Sun, 02 Oct 2022 04:12:37 GMT
content-length: 987654321
report-to: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=mvlI0%2BygL44HvQXozzMMpSlAPz8MQFuGN%2BkiepI50MFf8ZROKo0ap5%2F%2BRTTyeGopX2JVBYZOQV1RUnbAEsx9C2PxEkOraY9EMLGOWZXh2ks1oxtIQiIU78RjxDh0rm%2FHb3oKmeLi2KipEw3rzvbJMatR8z0%3D"}],"group":"cf-nel","max_age":604800}
nel: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
vary: Accept-Encoding
cf-ray: 753a99ce29928405-YVR
alt-svc: h3=":443"; ma=86400, h3-29=":443"; ma=86400
server: cloudflare
Connection: keep-alive
Keep-Alive: timeout=5

➤ curl --head http://0.0.0.0:8787/test2
HTTP/1.1 200 OK
date: Sun, 02 Oct 2022 04:12:43 GMT
content-type: application/json
report-to: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=tZy0y%2F%2BRiSD0sxPn4rDKZ%2FkOV665jhNC0HxibfX7rvFOM3rYmIWHmwK7ioQLB8ayyTxHny1wHZlLTNlzBYcY1WP22N271XFiXPwrSl2xqXmNJeLDoJ9TgK%2FbP%2F%2FABAUNxKpCa9CF3ArmSXXl5Zj0rBbUk4w%3D"}],"group":"cf-nel","max_age":604800}
nel: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
vary: Accept-Encoding
cf-ray: 753a99f4cb5e8405-YVR
alt-svc: h3=":443"; ma=86400, h3-29=":443"; ma=86400
server: cloudflare
Connection: keep-alive
Keep-Alive: timeout=5

I’m scratching my head trying to understand why this would be…

Issue Analytics

State:
Created a year ago
Comments:7 (2 by maintainers)

Top GitHub Comments

2reactions

alukachcommented, Oct 2, 2022

Thanks all. I have posted this to the Cloudflare Community’s Workers topic, however it was immediately flagged as spam. I’ll update this comment to link to the thread once it passes review.

1reaction

ThatOneBrocommented, Oct 2, 2022

I think Cloudflare Workers may be automatically overwriting your Content-Length header. This may be somewhat relevant: https://community.cloudflare.com/t/cant-set-content-length-for-get-requests/174487/2

EDIT: Here’s an interesting blog post that goes very in-depth about Cloudflare Workers and some weirdness with the Content-Length header. May be worth it to skim through it. https://www.codejam.info/2022/06/empty-body-no-body-http2.html