[Bug]: Refit 8 breaks ability to cast IApiResponse<T> to IApiResponse

[snake-scaly]

Describe the bug 🐞

The PR #1879 breaks our old code. Our API uses the generic version of IApiResponse<T>, but there are some implementation methods which accept the base IApiResponse. This works fine in 7.2.22. But in 8.0.0 IApiResponse<T>.Error and IApiResponse.Error are different fields, so in this case IApiResponse.Error is always null no matter what.

Steps to reproduce

In pseudocode:

interface Api
{
  [Get("/resource")]
  Task<IApiResponse<string>> Foo();
}

async Task Bar()
{
  var client = RestService.For<Api>("https://example.com");
  var response = await client.Foo();
  Verify(response);
}

void Verify(IApiResponse r)
{
  if (r.Error != null) throw r.Error; // never happens
}

Expected behavior

Applications should be able to use the base interface to access common response fields.

Refit Version

8.0.0

[sguryev]

Duplicate of #1933

[sguryev]

Not sure if I got your sample but I can't reproduce it here

Could you please provide the PR with test?

[snake-scaly]

So my bug report is incorrect. The production code will still work, it's just the mocking that's the problem. Good to know. Still, introducing a breaking change (even if just in tests) for slightly nicer IDE reporting seems excessive.

[sguryev]

Yep. It's a "kind of" breaking change. We need to find a tradeoff between mocking correct interfaces and using NRT annotations. And it's not about IDE reporting. It's analyzers (with warning as errors msbuild reports build errors)

[snake-scaly]

Closing as a duplicate, because #1933 is a much better description of the problem.