Fix error handling by returning original HTTP status

[ledermann]

Currently, an InertiaRails response has always the status code 200. This seems wrong to me, because if there was an error (like 404 or 500), the corresponding status code should be returned, not 200.

The Laravel adapter does the same thing, but the docs recommends overriding this behavior in the application - from what I understand.

This thing was discussed for the Laravel adapter some time ago. In Rails, error handling is different than in Laravel, so in my opinion returning the original status code should be returned. This fix allows handling errors I am doing in the PingCRM demo application.

Demo using the PingCRM for Rails demo application:

• Go to https://pingcrm.ledermann.dev and login
• Open developer console and open the Network tab
• Klick on the "404 error" button => The error is returned with code 200, which is wrong
• Open https://pingcrm.ledermann.dev/error-404 directly in the address line or do a full page reload, so a non-Inertia-request is made => Now the error is returned with code 404, which is correct

[ledermann]

Hi @bknoles and @BrandonShar, what do you think? IMHO this is a simple fix for an obvious bug.

[bknoles]

@ledermann does this conflict with #50 at all (conceptually)?

@reinink could you weigh in on whether returning 404s (or similar statuses) instead of 200s for error statuses fits into Inertialand ok?

[ledermann]

@bknoles I don't see any conflicts with #50. Also, the tests are green after merging both branches together. No issues from my side.