testgenerateprimes.java

著名的uncle Bob的Agile software development的代码

import junit.framework.*;

public class TestGeneratePrimes extends TestCase
{
  public static void main(String args[])
  {
      junit.swingui.TestRunner.main(
        new String[] {"TestGeneratePrimes"});
  }
  public TestGeneratePrimes(String name)
  {
    super(name);
  }

  public void testPrimes()
  {
    int[] nullArray = PrimeGenerator.generatePrimes(0);
    assertEquals(nullArray.length, 0);

    int[] minArray = PrimeGenerator.generatePrimes(2);
    assertEquals(minArray.length, 1);
    assertEquals(minArray[0], 2);

    int[] threeArray = PrimeGenerator.generatePrimes(3);
    assertEquals(threeArray.length, 2);
    assertEquals(threeArray[0], 2);
    assertEquals(threeArray[1], 3);

    int[] centArray = PrimeGenerator.generatePrimes(100);
    assertEquals(centArray.length, 25);
    assertEquals(centArray[24], 97);
  }

  public void testExhaustive()
  {
    for (int i = 2; i<500; i++)
        verifyPrimeList(PrimeGenerator.generatePrimes(i));
  }

  private void verifyPrimeList(int[] list)
  {
    for (int i=0; i<list.length; i++)
        verifyPrime(list[i]);
  }

  private void verifyPrime(int n)
  {
    for (int factor=2; factor<n; factor++)
      assert(n%factor != 0);
  }
}