start

TestApp::start runs the app main builds, unchanged, with every broker connected in process and no server.

The harness starts the app in the service's own order: on_startup, then each broker's connect, then the subscriptions, then after_startup. Each broker connects through its in-process transition, which performs no I/O and yields the broker's production connected form. MemoryBroker has no server, so its in-process mode is its ordinary connect. A networked broker provides the in-process mode under its crate's testing feature, which a service enables in [dev-dependencies]. A broker without it makes start fail with TestError::NoTransport naming the broker. A failing on_startup fails start with TestError::Startup before any broker connects. start_live runs the same app against a running stand, and with_state starts it with a state the test builds. A test ends with shutdown.

Example

Macros

examples/testing_starting.rs

#[tokio::test]
async fn a_refused_order_is_dropped() -> Result<(), Box<dyn Error>> {
    let tb = TestApp::start(app()).await?;
    tb.broker::<MemoryBroker>()
        .message(&Order { id: 13 })
        .publish()
        .await?;

    tb.broker::<MemoryBroker>()
        .subscriber("orders")
        .assert_called_once()
        .settled(HandlerOutcome::drop());
    Ok(())
}

Manual

examples/manual/testing_starting.rs

#[tokio::test]
async fn a_refused_order_is_dropped() -> Result<(), Box<dyn Error>> {
    let tb = TestApp::start(app()).await?;
    tb.broker::<MemoryBroker>()
        .message(&Order { id: 13 })
        .publish()
        .await?;

    tb.broker::<MemoryBroker>()
        .subscriber("orders")
        .assert_called_once()
        .settled(HandlerOutcome::drop());
    Ok(())
}