golang auto-restart app during development

restart.go

// 	"github.com/fsnotify/fsnotify"

	watcher, err := fsnotify.NewWatcher()
	defer watcher.Close()
	go func() {
		for {
			select {
			case event, _ := <-watcher.Events:
				fmt.Printf("PID %d, Event %v\n", os.Getpid(), event)
				if event.Op&fsnotify.Create == fsnotify.Create || event.Op&fsnotify.Write == fsnotify.Write {
					if strings.Contains(event.Name, ".go") || strings.Contains(event.Name, ".png") ||
						strings.Contains(event.Name, ".svg") || strings.Contains(event.Name, ".css") ||
						strings.Contains(event.Name, ".html") {
						fmt.Printf("PID %d, Event %v\n", os.Getpid(), event)
						os.Exit(0)

					}
				}
			}
		}
	}()
	watcher.Add(".")
	watcher.Add("assets/images")
	watcher.Add("assets/styles")
	watcher.Add("assets/js")
	watcher.Add("assets/templates/html")