Can you hint us more about how this is useful? Providing a mock won't really help out of the box so some pieces are missing, how do you do this? (the answer should be useful for the doc too.)

#30661 will have some interaction with this I suppose.

I plan to merge configuration as the 1st step and after merging it make mocking http client mutable and implement resettable interface, create some assertion trait.

Im on the fence with this PR.

Using the HttpClient in non-test, then it generally does not matter if I get the NativeClient or the CurlClient. (In the rare instances it actually matters, I define the service myself.)

Whenever I write tests with the HttpClient, I just define a service in my test environment. It is easier since I've got more control how I actually mock things.

So Im not sure this will actually be an improvement.

Closing as this PR is stale and two core team members are not convinced. Thanks for proposing.