ActiveRecord::RecordNotFound raises 404 instead of 500

Question

We had an action that was essentially failing silently in production because it was raising an ActiveRecord::RecordNotFound error, which Rails treats as a 404 error instead of a 500 error- meaning it wasn't being captured by our error logger.

I don't like that Rails maps certain errors to 404s- I think it should be up to the developer to decide whether a URL is invalid, or whether the failure to retrieve an record is an application error.

How do we ensure all Rails errors are treated as 500 errors?

Answer 1

First off, if you can manually notify your error logger of the error, that would probably be the best thing to do. Making Rails return a different HTTP status code might break other parts of your application.

However, if you absolutely must do so, you can instruct Rails not to return a 404 by removing the corresponding entry from the rescue responses hash. You could do this in an initializer:

# config/initializers/rescue_responses_overrides.rb
ActionDispatch::ExceptionWrapper.rescue_responses
  .delete('ActiveRecord::RecordNotFound')

Now Rails will send a 500 status code to the browser whenever ActiveRecord::RecordNotFound is raised. You could also remove all entries in a single step:

ActionDispatch::ExceptionWrapper.rescue_responses.clear

To see which other errors Rails returns different status codes for, you can simply print the hash in the Rails console:

pp ActionDispatch::ExceptionWrapper.rescue_responses