Events

// vukem make:event OrderShipped
type OrderShipped struct{ OrderID int64 }

// vukem make:listener NotifyCustomer --event OrderShipped [--async]
func NotifyCustomer(ctx context.Context, e events.OrderShipped) error { return nil }

// make:listener appends; bootstrap passes vukem.WithListeners(listeners.All()...)
func All() []events.Registration { return []events.Registration{events.OnAsync(NotifyCustomer)} }

err := app.Events.Dispatch(ctx, events.OrderShipped{OrderID: 42})

• events.On(fn) infers the event type from the function. Synchronous listeners run in registration order; the first error stops the chain and is returned to the caller.
• events.OnAsync(fn) listeners run on a bounded pool with a context detached from the request, log errors and panics, and are drained by app.Shutdown.
• events.Listen(bus, fn) and events.ListenAsync(bus, fn) register directly on a bus.
• Every security event is also dispatched as a security.Event.

Testing#

fake := events.NewFake()
_ = fake.Dispatch(ctx, events.OrderShipped{OrderID: 1})
shipped := events.Dispatched[events.OrderShipped](fake)

Queued listeners#

events.OnQueued("update_stock", listeners.UpdateStock) (or vukem make:listener UpdateStock --event OrderShipped --queued) stores the event as JSON and runs the listener in a queue worker, with the queue's retries. Dispatch only reports enqueue errors.