EqHash

The one Java class / method you need to test your objects' equals() and hashCode() methods.

• Save boilerplate code
• Get code coverage closer to 100%
• Best of all, get better mutation testing scores when using PIT et al.

public class EqHashTest {

  @Test
  public void testCustomObject() {
    final TestContainer orig = new TestContainer( 1, "a", new byte[]{46});
    // Assert that copy has same hashCode(), is equal etc.
    final TestContainer copy = new TestContainer( 1, "a", new byte[]{46});
    // Test all permutations for different hashCode(), not equal etc.
    final TestContainer diff1 = new TestContainer( 1, "a", new byte[]{46,47});
    final TestContainer diff2 = new TestContainer( 2, "a", new byte[]{46});
    final TestContainer diff3 = new TestContainer( 1, "b", new byte[]{46,47});

    EqHash.testEqualsHashcode( orig, copy, diff1, diff2, diff3);
  }

  [...]

  private static class TestContainer {
    private int x;
    private String y;
    private byte[] z;

    public TestContainer(int x, String y, byte[] z) {
      // Set fields etc.
    }