org.uma.jmetal.util.comparator.RankingAndCrowdingDistanceComparatorTest.java Source code

Introduction

Here is the source code for org.uma.jmetal.util.comparator.RankingAndCrowdingDistanceComparatorTest.java

Source

//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.

package org.uma.jmetal.util.comparator;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.springframework.test.util.ReflectionTestUtils;
import org.uma.jmetal.solution.Solution;

import java.util.Comparator;

import static org.junit.Assert.assertEquals;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.*;

/**
 * @author Antonio J. Nebro <antonio@lcc.uma.es>
 * @version 1.0
 */
public class RankingAndCrowdingDistanceComparatorTest {
    private RankingAndCrowdingDistanceComparator<Solution<?>> comparator;

    @Before
    public void setup() {
        comparator = new RankingAndCrowdingDistanceComparator<Solution<?>>();
    }

    @After
    public void teardown() {
        comparator = null;
    }

    @Test
    public void shouldCompareTwoNullSolutionsReturnZero() {
        assertEquals(0, comparator.compare(null, null));
    }

    @Test
    public void shouldCompareWithANullSolutionAsFirstArgumentReturnOne() {
        Solution<?> solution = mock(Solution.class);
        assertEquals(1, comparator.compare(null, solution));
    }

    @Test
    public void shouldCompareWithANullSolutionAsSecondArgumentReturnMinusOne() {
        Solution<?> solution = mock(Solution.class);
        assertEquals(-1, comparator.compare(solution, null));
    }

    @Test
    public void shouldCompareWithNullRankingAttributeSolutionAsFirstArgumentReturnOne() {
        Solution<?> solution2 = mock(Solution.class);

        assertEquals(1, comparator.compare(null, solution2));
    }

    @Test
    public void shouldCompareWithRankingYieldingANonZeroValueReturnThatValue() {
        Comparator<Solution<?>> rankComparator = mock(Comparator.class);

        when(rankComparator.compare(any(Solution.class), any(Solution.class))).thenReturn(1);

        ReflectionTestUtils.setField(comparator, "rankComparator", rankComparator);

        Solution<?> solution1 = mock(Solution.class);
        Solution<?> solution2 = mock(Solution.class);
        assertEquals(1, comparator.compare(solution1, solution2));
        verify(rankComparator).compare(solution1, solution2);
    }

    @Test
    public void shouldCompareWhenRankingYieldingAZeroReturnTheCrowdingDistanceValue() {
        Comparator<Solution<?>> rankComparator = mock(Comparator.class);
        when(rankComparator.compare(any(Solution.class), any(Solution.class))).thenReturn(0);

        Comparator<Solution<?>> crowdingDistanceComparator = mock(CrowdingDistanceComparator.class);
        when(crowdingDistanceComparator.compare(any(Solution.class), any(Solution.class))).thenReturn(-1);

        ReflectionTestUtils.setField(comparator, "rankComparator", rankComparator);
        ReflectionTestUtils.setField(comparator, "crowdingDistanceComparator", crowdingDistanceComparator);

        Solution<?> solution1 = mock(Solution.class);
        Solution<?> solution2 = mock(Solution.class);

        assertEquals(-1, comparator.compare(solution1, solution2));
        verify(rankComparator).compare(solution1, solution2);
        verify(crowdingDistanceComparator).compare(solution1, solution2);
    }
}