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    * The ASF licenses this file to You under the Apache License, Version 2.0
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    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
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  package org.apache.commons.math4.legacy.genetics;
  
  import org.junit.Assert;
  import org.junit.Test;
  
  public class OnePointCrossoverTest {
  
      @Test
      public void testCrossover() {
          @SuppressWarnings("boxing")
          Integer[] p1 = new Integer[] {1,0,1,0,0,1,0,1,1};
          @SuppressWarnings("boxing")
          Integer[] p2 = new Integer[] {0,1,1,0,1,0,1,1,1};
  
          BinaryChromosome p1c = new DummyBinaryChromosome(p1);
          BinaryChromosome p2c = new DummyBinaryChromosome(p2);
  
          OnePointCrossover<Integer> opc = new OnePointCrossover<>();
  
          // how to test a stochastic method?
          for (int i=0; i<20; i++) {
              ChromosomePair pair = opc.crossover(p1c,p2c);
  
              Integer[] c1 = new Integer[p1.length];
              Integer[] c2 = new Integer[p2.length];
  
              c1 = ((BinaryChromosome) pair.getFirst()).getRepresentation().toArray(c1);
              c2 = ((BinaryChromosome) pair.getSecond()).getRepresentation().toArray(c2);
  
              // first and last values will be the same
              Assert.assertEquals(p1[0],  c1[0]);
              Assert.assertEquals(p2[0], c2[0]);
              Assert.assertEquals(p1[p1.length-1], c1[c1.length-1]);
              Assert.assertEquals(p2[p2.length-1], c2[c2.length-1]);
              // moreover, in the above setting, the 2nd, 3rd and 7th values will be the same
              Assert.assertEquals(p1[2], c1[2]);
              Assert.assertEquals(p2[2], c2[2]);
              Assert.assertEquals(p1[3], c1[3]);
              Assert.assertEquals(p2[3], c2[3]);
              Assert.assertEquals(p1[7], c1[7]);
              Assert.assertEquals(p2[7], c2[7]);
          }
      }
  }