CQRS

A extremely simple set of interfaces for cqrs usage:

• cqrs.CommandHandler
• cqrs.QueryHandler
• cqrs.EventHandler

CommandHandler

type ExampleCommand struct {
	Value string
}

type ExampleHandler struct {
	repo ExampleRepo
}

func NewExampleHandler(
	repo ExampleRepo,
) cqrs.CommandHandler[*ExampleCommand] {
	return &ExampleHandler{
		repo:    repo,
	}
}

func (h *ExampleHandler) Handle(ctx context.Context, command *ExampleCommand) error {
	return repo.DoSomething(ctx, command.Value)
}

QueryHandler

type ExampleQuery struct {
	Id string
}

type ExampleHandler struct {
	repo ExampleRepo
}

func NewExampleHandler(
	repo ExampleRepo,
) cqrs.QueryHandler[*ExampleQuery, *Entity] {
	return &ExampleHandler{
		repo:    repo,
	}
}

func (h *ExampleHandler) Handle(ctx context.Context, query *ExampleQuery) (*Entity, error) {
	return repo.GetExampleEntity(ctx, query.Id)
}

EventHandler

type ExampleEvent struct {
	Value string
}

type ExampleHandler struct {
	service ExampleService
}

func NewExampleHandler(
	service ExampleService,
) cqrs.EventHandler[*ExampleEvent] {
	return &ExampleHandler{
		service:    service,
	}
}

func (h *ExampleHandler) Handle(ctx context.Context, event *ExampleEvent) error {
	return service.Handle(ctx, event.Value)
}