Incorrect error message when server loader throws an error and clientLoader is present

[justinwaite]

Reproduction

https://stackblitz.com/edit/remix-run-remix-uyj9e9?file=app%2Froutes%2F_index.tsx

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.18.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 9.4.2 - /usr/local/bin/npm
    pnpm: 8.10.5 - /usr/local/bin/pnpm
  npmPackages:
    @remix-run/css-bundle: 2.4.0 => 2.4.0 
    @remix-run/dev: 2.4.0 => 2.4.0 
    @remix-run/node: 2.4.0 => 2.4.0 
    @remix-run/react: 2.4.0 => 2.4.0 
    @remix-run/serve: 2.4.0 => 2.4.0

Used Package Manager

npm

Expected Behavior

When an error is thrown in a server loader, I expect to be able to capture that error message and display it to the user in an error boundary. The error message in the reproduction that should be displayed is:

This is an error message that should render in the boundary.

Actual Behavior

I get an initial flash of the expected error message, but quickly overridden by:

You defined a loader for route "routes/_index" but didn't return anything from your `loader` function. Please return a value or `null`.

If you remove the clientLoader, this behavior goes away.

Note: if you are looking at the stackblitz and see the "correct" error message, just refresh the app and most of the time you will see the "incorrect" error message as described above.

[justinwaite]

After some further investigation, it seems the problem is that calling serverLoader in the clientLoader function returns undefined in the event of loader throwing an error. Then undefined gets returned from clientLoader. I would expect that if loader throws an error, then calling serverLoader would likewise throw an error instead of undefined.

[brophdawg11]

Thanks for the reproduction and investigation!

[brophdawg11]

Resolved by #8304 and will be in the next release 👍

[justinwaite]

@brophdawg11 you guys are lightning fast. Thanks!

[github-actions]

🤖 Hello there,

We just published version 2.4.1-pre.0 which involves this issue. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 2.4.1 which involves this issue. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!