Compressing response breaking error page

[b-mounir-dev]

Environment

Working directory: /home/projects/nuxt-starter-xkjsve 1:20:34 PM
Nuxt project info: 1:20:34 PM

---

• Operating System: Linux
• Node Version: v18.18.0
• Nuxt Version: 3.11.2
• CLI Version: 3.11.1
• Nitro Version: 2.9.6
• Package Manager: npm@10.2.3
• Builder: -
• User Config: devtools
• Runtime Modules: -
• Build Modules: -

---

👉 Report an issue: https://github.com/nuxt/nuxt/issues/new 1:20:34 PM

👉 Suggest an improvement: https://github.com/nuxt/nuxt/discussions/new

👉 Read documentation: https://nuxt.com

Reproduction

https://stackblitz.com/edit/nuxt-starter-xkjsve

Describe the bug

I use code below to compress response before output using brotlli/gzip/deflate method, it's working good when response 200, but for 404/500 error pages this code doesn't work in async page:

import { Readable, pipeline } from 'node:stream';
import zlib from 'node:zlib';

export default defineNitroPlugin((nitroApp) => {
  nitroApp.hooks.hook('beforeResponse', async (event, response) => {
    compressResponse(event, response);
  });
});

async function compressResponse(event: any, response: { body?: unknown }) {
  if (typeof response.body !== 'string') {
    return;
  }

  // using deflate as fallback here bcz stackblitz doesn't include it in req headers
  // You can test locally without setting fallback
  const acceptableEncoding =
    getRequestHeader(event, 'accept-encoding') ?? 'deflate';

  if (
    !acceptableEncoding ||
    !/\b(deflate|gzip|br)\b/.test(acceptableEncoding)
  ) {
    return;
  }

  const originalBody = response.body;
  const stream = Readable.from(response.body);

  if (/\bbr\b/.test(acceptableEncoding)) {
    setResponseHeader(event, 'Content-Encoding', 'br');
    response.body = pipeline(
      stream,
      zlib.createBrotliCompress(),
      event.node.res,
      () => (response.body = originalBody)
    );
  } else if (/\bgzip\b/.test(acceptableEncoding)) {
    setResponseHeader(event, 'Content-Encoding', 'gzip');
    response.body = pipeline(
      stream,
      zlib.createGzip(),
      event.node.res,
      () => (response.body = originalBody)
    );
  } else {
    setResponseHeader(event, 'Content-Encoding', 'deflate');
    response.body = pipeline(
      stream,
      zlib.createDeflate(),
      event.node.res,
      () => (response.body = originalBody)
    );
  }
}

Additional context

No response

Logs

No response

[stackblitz]

Start a new pull request in StackBlitz Codeflow.

• nuxt-starter-xkjsve (Open reproduction)

[aaharu]

Since /__nuxt_error is broken trying to compress, adding the following to compressResponse may work.

    if (getRequestURL(event).pathname.startsWith('/__nuxt')) {
      return
    }

However, it may be recommended to do this with a proxy rather than compressing with the nitro plugin.
unjs/nitro#1007 (comment)