Crate tower_test 

Mock Services for use in tests.

When testing code built on tower, it is often useful to swap a real service for one whose behaviour the test controls. mock::Mock is a Service that does nothing on its own: each request it receives is handed to a paired mock::Handle, and the response is whatever the test chooses to send back through that handle. This makes it possible to assert on the exact requests a Service makes and to decide, per request, how to respond (including failing).

Create a Mock/Handle pair with mock::pair, or use mock::spawn() to get a mock::Spawn wrapper whose readiness can be polled synchronously in tests (for example with tokio-test).

Example

use tokio_test::{assert_ready_ok, block_on};
use tower_service::Service;
use tower_test::mock;

// Create a mock service together with the handle used to drive it.
let (mut service, mut handle) = mock::spawn();

// A freshly-created mock is ready to accept a request.
assert_ready_ok!(service.poll_ready());

// Calling the service sends the request to the handle and returns a future
// that resolves once the handle responds.
let response = service.call("hello");

// Receive the request through the handle and reply to it.
let (request, send_response) =
    block_on(handle.next_request()).expect("the service was called");
assert_eq!(request, "hello");
send_response.send_response("world");

// Now that a response has been sent, the service's response future resolves.
assert_eq!(block_on(response).unwrap(), "world");

Modules

mock

Mock Services for use in tests.

Macros

assert_request_eq

Asserts that the mock handle receives a new request equal to the given value.