Improvement suggestion for Middleware type definition

[yicrotkd]

Description

The middleware throws the following error when neither onRequest() nor onResponse() is provided.

"Middleware must be an object with one of onRequest() or onResponse()"
https://github.com/openapi-ts/openapi-typescript/blob/main/packages/openapi-fetch/src/index.js#L223

Based on this, I think the type definition below could be improved by making it more explicit and better aligned with the intended behavior: https://github.com/openapi-ts/openapi-typescript/blob/main/packages/openapi-fetch/src/index.d.ts#L147

Proposal

It seems like the Middleware interface might be improved with the following modification:

export type Middleware {
  onRequest?: ...;
  onResponse: ...;
} | {
  onRequest: ...;
  onResponse?: ...;
}

This modification ensures that either onRequest or onResponse is required, and this is reflected in the type, allowing the issue to be detected at compile time.

Checklist

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

[drwpow]

Good suggestion! I’d be open to a PR for this

[yicrotkd]

Thank you for the quick response! I’m glad the suggestion makes sense. Just to clarify, I was actually planning to open a PR for this myself, as mentioned in the checklist. I’ll go ahead and submit it shortly.

If possible, I’d really appreciate your feedback once the PR is open!

[yicrotkd]

I've created the PR.

#1918

I would appreciate it if you could review it when you have the time.