Pragmatic Unit Testing(2): Your First Unit Test

/* Pragmatic Unit Testing(2): the first unit test
   created on Mar 30, 2011
   */
public class Largest {

    public static int largest(int[] list) {
        int index, max =  Integer.MIN_VALUE; //try max = Integer.MAX_VALUE and max = 0
        if(list.length == 0) {
            throw new RuntimeException("Empty list");
        }

        for(index = 0; index < list.length; index++) { //try index < list.length-1
            if(list[index] > max) {
            max = list[index];
            }
        }
        return max;
    }
}///:~

/* A first test for Largest.largest() method
   created on Mar 30, 2011
   */

import junit.framework.*;

public class TestLargest extends TestCase {
    public TestLargest(String name) {
        super(name);
    }

    public void testSimple() {
        assertEquals(9, Largest.largest(new int[] {7, 8, 9}));
    }

    public void testOrder() {
        assertEquals(9, Largest.largest(new int[] {9, 7, 8}));
        assertEquals(9, Largest.largest(new int[] {7, 9, 8}));
    }

    public void testDups() {
        assertEquals(9, Largest.largest(new int[] {9, 9, 7, 8}));
    }

    public void testNegtive() {
        int[] negList = new int[] {-9, -8, -7};
        assertEquals(-7, Largest.largest(negList));
    }

    public void testOne() {
        assertEquals(1, Largest.largest(new int[] {1}));
    }

    public void testEmpty() {
        try{
            Largest.largest(new int[] {});
            fail("Should have thrown an exception ");
        } catch (RuntimeException e) {
            assertTrue(true);
        }
    }
}