Wrong http status code (500) returned instead of 404 or any response thrown from a loader.

[zvin]

Have you experienced this bug with the latest version of the template?

yes

Steps to Reproduce

• npx create-remix@latest;
• select the blues template, follow the suggested steps;
• go to any page that doesn't exist, http://0.0.0.0:3000/no-such-page for example
• see that the returned status is 500 instead of 404

The same issue happens if you throw a json response in a loader: throw json("Unauthorized", { status: 403 });, a 500 status code will be returned to the browser.

It seems like this started happening when updating remix from 1.9.0 to 1.10.0.
The issue does not happen when using remix serve instead of express.
I don't know if the issue comes from the template server.ts file or from the combination of @remix-run/react and @remix-run/express

Expected Behavior

A 404 http status code should be returned.

Actual Behavior

A 500 http status code is returned.

[zvin]

Minimal reproduction here: https://stackblitz.com/edit/node-zxrwpd

[zvin]

One thing that solves the issue is to remove the eslint --bundle flag here

[machour]

This is an intended behavior in production, see Matt's answer here: remix-run/remix#5115 (comment)

[zvin]

I don't think that this is the same issue.
It also happens in development.
And even in production a page that doesn't exist should send a 404, not a 500.
The behavior differs from previous remix versions and from running it with remix serve.

[zvin]

The issue does not happen when not using eslint's --bundle flag or running server.ts with ts-node directly.

[brophdawg11]

This looks like an issue with the bundling approach causing multiple disparate ErrorResponse classes to exist and this causing internal instanceof ErrorResponse checks to fail. We'll need to change those checks to avoid using instanceof for bundling approaches like this and instead use prop detection

[brophdawg11]

The above merged PR will go in the next react router release, either 6.7.1 or 6.8.0 depending on what is in it. Then Remix will pick that up in it's next release.

[zvin]

Thanks for the quick fix!

[brophdawg11]

This should be fixed with Remix 1.12.0 which should be out in the next hour or two