hyper-stub

hyper-stub is a Rust library that provides functions to create hyper clients that convert requests to responses using predefined functions, without doing any actual networking. This means the entire request/response lifecycle happens in a single process, and should have performance and stability improvements over, for example, binding to a port. One potential use case for this is stubbing HTTP interactions in tests to avoid slow/flakey/absent internet connections.

For API reference and usage examples, see the documentation.

lib.rs:

hyper-stub provides functions to create hyper clients that convert requests to responses using predefined functions, without doing any actual networking. This means the entire request/response lifecycle happens in a single process, and should have performance and stability improvements over, for example, binding to a port. One potential use case for this is stubbing HTTP interactions in tests to avoid slow/flakey/absent internet connections.

The simplest case uses proxy_client_fn_ok to create a client bound to a simple function that directly maps from a request to a response:

#
use futures::{Future, Stream};
use hyper::{Request, Response, Uri};
use hyper_stub::proxy_client_fn_ok;
use tokio::runtime::current_thread::Runtime;

let echo_client = proxy_client_fn_ok(|request| {
    let body = request.into_body();
    Response::new(body)
});

let url: Uri = "http://example.com".parse().unwrap();
let mut builder = Request::post(url);
let request = builder.body("hello world".into()).unwrap();
let future = echo_client.request(request)
    .and_then(|res| res.into_body().concat2())
    .map(|bytes| {
        let body = String::from_utf8(bytes.to_vec()).unwrap();
        println!("{}", body);
    })
    .map_err(|error| panic!("ERROR: {:?}", error));

Runtime::new().unwrap().block_on(future).unwrap();

If the function needs to return an error, or respond to the request asynchronously, proxy_client_fn can be used.

Finally, an advanced use case is using hyper services instead of simple functions. This can be done with the proxy_client function.