Write an automated test that would be able to verify that the function is working correctly (feel free to use any coding language of your choice

import javax.swing.*;
public class validation {
 public static void main(String[] args) {
 String cellphoneNumber;
 cellphoneNumber= JOptionPane.showInputDialog("Please enter your cellphone number = ) ");
 if (validateSAPhoneNumber(cellphoneNumber)) {
 JFrame frame = new JFrame("Input Dialog");
 JOptionPane.showMessageDialog(frame,
 "Cellphone number is valid =)");
 System.exit(0);
 }else
 {
 JFrame frame = new JFrame("Output Dialog");
 JOptionPane.showMessageDialog(frame,
 "Cellphone number is invalid =(");
 System.exit(0);
 }
 }
 public static boolean validateSAPhoneNumber(String cellphoneNumber) {
 if(cellphoneNumber.matches("^((?:\\+27|27)|0)(\\d{2})-?(\\d{3})-?(\\d{4})$")){
 return true;
 }else{
 return false;
 }
 }
}