Überprüfung spezifischer Fehlerketten mit Errors Is

package main
 
import (
	"errors"
	"fmt"
)
 
var ErrNotFound = errors.New("resource not found")
 
func fetchResource() error {
	return fmt.Errorf("database query failed: %w", ErrNotFound)
}
 
func main() {
	err := fetchResource()
	if errors.Is(err, ErrNotFound) {
		fmt.Println("Handled: The resource indeed could not be found.")
	} else {
		fmt.Println("Error:", err)
	}
}