Tests: Wait until server has started?

[bes]

Hi!

I want to know if there is a good way to wait until axum has started before running tests?

Here's how I usually start the server:

pub async fn run_server(port: u16) {
    let server_state = Arc::new(AxumState {
        // ...
    });
    let cors = CorsLayer::new()
        .allow_methods([Method::GET, Method::HEAD])
        .allow_origin(Any);

    let app = Router::new()
        .merge(/**/)
        .merge(/**/)
        .with_state(server_state)
        .layer(cors);

    let addr = SocketAddr::from(([127, 0, 0, 1], port));
    match axum::Server::bind(&addr)
        .serve(app.into_make_service())
        .await
    {
        Ok(_) => tracing::info!("Axum exited cleanly"),
        Err(err) => tracing::warn!("Axum exited with an error {}", err),
    }
}

And the test is here:

#[tokio::test]
async fn test_server() -> Result<(), anyhow::Error> {
    let server_handle = tokio::spawn(run_server(SERVER_PORT));

    // Test fails unless I sleep here
    // tokio::time::sleep(Duration::from_secs(1)).await;

   // Here I want to do a network call and assert the result

    server_handle.abort();
    Ok(())
}

Is there a "server started" callback that I can use to send a message on a channel? Or something else, so that I don't have to sleep before running the test?

Thanks.

[davidpdrsn]

You can use https://docs.rs/hyper/0.14.23/hyper/server/struct.Server.html#method.builder

[davidpdrsn]

Or like this https://github.com/tokio-rs/axum/blob/main/examples/testing/src/main.rs#L125

[bes]

Thanks @davidpdrsn but I don't understand how those resources would help me.

I forgot to add in my code above that I am already doing

reqwest::get(format!("http://127.0.0.1:{SERVER_PORT}/{path}"))
            .await?
            .error_for_status()?

But unless I wait for a little while before issuing the request, the test fails with this:

---- server::tests::test_server stdout ----
Error: error sending request for url (http://127.0.0.1:51130/somepath): error trying to connect: tcp connect error: Connection refused (os error 61)

[davidpdrsn]

In the test example the listener is created first so the server is immediately ready.

[bes]

Thanks, it worked 👍