How to mock external traits?

[vigenere23]

Let's say I use an external library that provides an HTTP Client, like a trait SpotifyClient with some basic implementations. I want to mock the responses of the client and verify the requests made in order to test some logic that my code does (as a large integration test).

Currently, from the examples, you can only add mocks using the #[mock_it] or #[cfg_attr(mock_it)] directives, which cannot be added on external code...

Is there any other utilities I can use from this library to overcome this issue? Because I really like the simplicity and directness of the API 😄

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Would the solution be to create an implementation classe, like struct FakeSpotifyClient, that implements the SpotifyClient trait but with todo!()s, and add the #[mock_it] directive to it?