Contents

./MutantRevealer.java

package revealer;

import static org.junit.jupiter.api.Assertions.assertArrayEquals;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.Arrays;

import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;

import mutants.Mutant;
import testthetests.MutantMaker;

/**
 * Contains the test cases that will reveal the mutants. Creates a mutant that
 * will be used to run the tests against.
 * 
 * Do NOT run this class directly.
 * 
 * @author Shannon Duvall original concept
 * @author Sara Sprenkle refactoring, documentation, updated for JUnit 5, updated examples
 */
public class MutantRevealer {

    // In typical JUnit tests, this would be a non-static variable.
    static Mutant mutant;
    
    @BeforeAll
    public static void getMutant() {
	// gets the mutant we're going to try to reveal
	mutant = MutantMaker.getNextMutant();
    }

    @Test
    public void testTypicalBehavior() {
	String[][] tests = { { "a", "ab", "abc" }, { "1", "12", "12345345", "234oi34iuwer", "12345" }};
	assertEquals("abc", mutant.thirdShortest(tests[0]));
	assertEquals("12345", mutant.thirdShortest(tests[1]));
    }

    @Test
    public void testExceptionNull() {
	assertThrows(IllegalArgumentException.class, () -> {
		mutant.thirdShortest(null);
	    });
    }
    
    @Test
    public void testExceptionEmpty() {
	assertThrows(IllegalArgumentException.class, () -> {
		mutant.thirdShortest(new String[] {});
	    });
    }
    
    @Test
    public void testExceptionLength1() {
	assertThrows(IllegalArgumentException.class, () -> {
		mutant.thirdShortest(new String[] { "hey" });
	    });
    }
    
    @Test
    public void testExceptionLength2() {
	assertThrows(IllegalArgumentException.class, () -> {
		mutant.thirdShortest(new String[] { "hey", "there" });
	    });	
    }

    @Test
    public void testNoThirdShortest() {
	assertNull(mutant.thirdShortest(new String[] { "cba", "abc", "bca" }));
    }
    
    @Test
    public void testMoreInArrayTie() {
	String[] words = { "a", "b", "c", "d", "ab", "ba", "de", "few", "answers" };
	String[] original = { "a", "b", "c", "d", "ab", "ba", "de", "few", "answers" };
	String result = mutant.thirdShortest(words);
	assertTrue(result.equals("few") || result.equals("answers"));
	
	// make sure the array hasn't changed
	assertEquals(Arrays.asList(words), Arrays.asList(original));	
    }

    @Test
    public void testMoreInArray() {
	String[] words = { "abcds", "b", "bc", "ab", "bye", "and" };
	String[] original = { "abcds", "b", "bc", "ab", "bye", "and" };
	String result = mutant.thirdShortest(words);
	assertTrue(result.equals("bye") || result.equals("and"));
	
	// make sure the array hasn't changed
	assertArrayEquals(original, words);
    }
    
    @Test
    public void testMoreInArray2() {
	String[] words = { "a", "b", "bc", "ab", "bye", "and" };
	String[] original = { "a", "b", "bc", "ab", "bye", "and" };
	String result = mutant.thirdShortest(words);
	assertTrue(result.equals("bye") || result.equals("and"));
	
	// make sure the array hasn't changed
	assertArrayEquals(original, words);
    }

}