package event_test import ( "testing" "go.sour.is/ev/event" ) type Agg struct { Value string event.IsAggregate } var _ event.Aggregate = (*Agg)(nil) func (a *Agg) streamID() string { return "value-" + a.Value } // ApplyEvent applies the event to the aggrigate state func (a *Agg) ApplyEvent(lis ...event.Event) { for _, e := range lis { switch e := e.(type) { case *ValueApplied: a.Value = e.Value a.SetStreamID(a.streamID()) } } } type ValueApplied struct { Value string event.IsEvent } var _ event.Event = (*ValueApplied)(nil) func TestAggregate(t *testing.T) { agg := &Agg{} event.Append(agg, &ValueApplied{Value: "one"}) }