Testing tower layer used by Hyper

[phughk]

Hi all,

I have a tower layer that I have configured to accept Hyper types.

impl hyper::service::Service<Request<Incoming>> for MyService {
    type Response = Response<String>;
    type Error = RapidRecastError;
    type Future = BoxFuture<'static, Result<Self::Response, Self::Error>>;

    fn call(&self, req: Request<Incoming>) -> Self::Future {
       // ...
    }
}

I am now trying to test this, and it is proving difficult, since I cannot construct an Incoming type.

    let req = http::Request::builder()
        .method("POST")
        .uri("/test")
        .body(Incoming::from("whatever body"))
        .unwrap();
    let resp = tower.call(req).await;

Any pointers would be fantastic 🙏

[phughk]

Wondering if I should be using the http-body-utils crate, but not sure how that maps to Incoming
https://github.com/hyperium/http-body/tree/master/http-body-util/src

[seanmonstar]

The Incoming type is purposefully not meant to be constructable outside of hyper.

If you want to be able to test your service, without starting up a TCP server (which is what I do a lot, this works just fine), then you need to make your service generic over the request body. That way, it can accept both Incoming and also some mocked body in your unit tests.

It's a good point, I've updated the guides revamp issue (#3411) to add a guide about testing your service.

[phughk]

For anyone wanting the solution to this, I have given the example from @nylonicious on Discord - it solves the problem perfectly.
https://github.com/rapidrecast/blog-post-snippets/tree/2b4a574401ea4f610c98b122cbcb489acdc401ba/blog-20241202-hyper-service/src