When a server returns an error status code without content, the error is present but undefined

[julienw]

openapi-fetch version

Latest

Description

The context is this code:

openapi-typescript/packages/openapi-fetch/src/index.js

Line 235 in 12f9c29

return response.ok ? { data: undefined, response } : { error: undefined, response };

I wonder if we shouldn't have a tru-ish value (maybe just "true") for error here, so that the calling code can simply use if (error). What do you think?

Reproduction

The problem happens when a server returns an error status (such as 405) without any content.

Expected result

The caller can do if (error) simply.

Extra

• I’m willing to open a PR (see CONTRIBUTING.md)

[matteom-synth]

I've also just been bitten by this default behaviour, which I feel is quite dangerous. I would also recommend returning some sort of truthy value here, but I can see it being problematic with the current way the error is returned.
I understand it would be a breaking change (and I'm probably missing context!) but I feel it might be easier if the error was an object with "status" and "content" (or something similar) so that consumers could always have access to these informations while keeping the option of having an empty response.

[matteom-synth]

To avoid patching the lib, for now I'm using a middleware to handle this case (still haven't tested it properly):

function emptyErrorResponseMiddleware(): Middleware {
  return {
    async onResponse({ response }) {
      if (response.ok) {
        return response;
      }
      const error = await response.clone().text();
      if (error) {
        return response;
      }
      return new Response("Empty response", response);
    },
  };
}