#format java

/* Sample of Recursion and JUnit
 */

import junit.framework.*;

class FactorialException extends ArithmeticException {
}

class Factorial {
    private int fact(int aNum) {
        if(aNum < 1)
            throw new FactorialException();
        if(aNum == 1)
            return 1;
        else 
            return aNum * fact(aNum-1);
    }
    public int get(int aNum) {
        return fact(aNum);
    }
}

public class FactorialTest extends TestCase {
    public static void main(String[] args) {
        junit.textui.TestRunner.run(FactorialTest.class);
    }
    Factorial f = new Factorial();
    public void test1() {
        assertEquals(1, f.get(1));
    }
    public void test2() {
        assertEquals(2, f.get(2));
    }
    public void testNegative() {
        int impossible;
        try {
            impossible = f.get(-2);
            fail("Factorial input must positive");
        } catch (FactorialException success) {
        }
    }
}