Extract Chi routing from main.go with handlers struct

main.go

func main() {
  ...
  mux := handler(conf)
  ...
}

func handler(conf config.Config) chi.Router {
	db, err := gorm.Open(mysql.Open(conf.Database.String), &gorm.Config{
		SkipDefaultTransaction: true,
	})
	if err != nil {
		panic(err)
	}

	// DI
	messageRepo := message.NewRepository(db)
	userRepo := user.NewRepository(db)

	messageSvc := services.NewMessageService(messageRepo)
	userSvc := services.NewUserService(messageRepo, userRepo)

	imageHandler := handlers.NewImageHandler()
	messageHandler := handlers.NewMessageHandler(messageSvc)
	userHandler := handlers.NewUserHandler(userSvc)

	return router.Init(conf, &router.Handlers{
		Image:   imageHandler,
		Message: messageHandler,
		User:    userHandler,
	})
}

router.go

type Handlers struct {
	Image   *handlers.ImageHandler
	Message *handlers.MessageHandler
	User    *handlers.UserHandler
}

func Init(conf config.Config, hh *Handlers) chi.Router {
	r := chi.NewRouter()
	initMiddleware(conf, r)
	initRoutes(r, hh)
	return r
}

func initRoutes(r chi.Router, hh *Handlers) {
	// ALB health check
	r.Get("/support", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	})

	// v1
	r.Route("/support/v1", func(r chi.Router) {
		r.Route("/users", func(r chi.Router) {
			r.Get("/", hh.User.List)
			r.Get("/{id}", hh.User.FindByID)
			r.Get("/{id}/messages", hh.Message.FindByUserID)
		})
		r.Route("/messages", func(r chi.Router) {
			r.Post("/", hh.Message.CreateMessage)
			r.Delete("/{id}", hh.Message.DeleteByID)
		})
		r.Route("/images", func(r chi.Router) {
			r.Post("/issue", hh.Image.IssueUploadURL)
		})
	})
}