Cannot test my own REST API from a beta managed package

Question

I developed a REST API for my managed package which works correctly when tested for development in my scratch org but also as a released managed package.

Recently I made minor changes to it - like simply adding the support for an additional query string parameter, nothing extraordinary - and, although it works just fine both on my scratch org and on my packaging org, it doesn't when tested as a beta package. But it's not the change that doesn't work, it's the whole service.

I get a 403 HTTP status code with the payload below whenever I call any of my endpoints:

[
  {
    "errorCode": "FORBIDDEN",
    "message": "Request blocked due to package versioning restrictions"
  }
]

Answer 1

I figured out what happened. Sadly, if you got to that point there's no solution for it, just a workaround.

You will encounter this error if you first package a global class similar to this.

@RestResource(urlMapping='/my-pretty-path/*')
global with sharing class MyPrettyRestHandler {

    @HttpGet
    global static void doGet() {
        // My pretty logic
    }

}

Beautiful, isn't it? But we all know the rules: once a global class gets packaged and the package is released that class cannot be retired anymore... well, kind of... there's still a painful way you can look into if you really want to (Revert a managed package to a beta version).

However there's literally NO WAY to EVER amend your mistakes if you persevere in the error... enter the @deprecated annotation. In the context of a REST handling class this useful - cough - annotation will help you achieve the perfect path nuking. You just add it like so:

@RestResource(urlMapping='/my-pretty-path/*')
@deprecated
global with sharing class ApplicationRestProvider {
    ...

Next you create a new package version (or simply a new version?) and you can high-five yourself. You just made my-pretty-path unusable to time indefinite. The solution for you now is the one of choosing a different path and ask all of your customers using that REST API path to migrate to a different path. Isn't that great? Well, in the end it's me who wanted it...