multiple errors

errs.go

type errs []error

func (e errs) Error() string {
	s := make([]string,len(e))
	for i, err := range e {
		s[i] = err.Error()
	}
	return strings.Join(s,",")
}

func (e errs) Unwrap() error {
	err := e[1:]
	if len(err) == 0 {
		return nil
	}
	if len(err) == 1 {
		return err[0]
	}
	return err
}

func (e errs) Is(err error) bool {
	for _, ee := range e {
		if errors.Is(ee,err){
			return true
		}
	}
	return false
}

func (e errs) As(target interface{}) bool {
	for _, ee := range e {
		if errors.As(ee, &target){
			return true
		}
	}
	return false
}