package com.atlassian.cache.ehcache;
   
   import com.atlassian.cache.impl.ReferenceKey;
   import org.junit.Test;
   
   import java.lang.reflect.Constructor;
   import java.lang.reflect.Field;
   
   import static java.lang.reflect.Modifier.isFinal;
  import static java.lang.reflect.Modifier.isPrivate;
  import static org.apache.commons.lang3.SerializationUtils.deserialize;
  import static org.apache.commons.lang3.SerializationUtils.serialize;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotSame;
  import static org.junit.Assert.assertTrue;
  
  public class ReferenceKeyTest
  {
      @Test
      public void noArgConstructorShouldBePrivateToPreventInstantiationByOtherClasses() throws Exception
      {
          // Invoke
          final Constructor<ReferenceKey> noArgConstructor = ReferenceKey.class.getDeclaredConstructor();
  
          // Check
          assertTrue("No-arg constructor should be private", isPrivate(noArgConstructor.getModifiers()));
      }
  
      @Test
      public void singletonShouldBeFinalToPreventReassignmentForExampleToNull() throws Exception
      {
          // Invoke
          final Field keyField = ReferenceKey.class.getDeclaredField("KEY");
  
          // Check
          assertTrue("Key field should be final", isFinal(keyField.getModifiers()));
      }
  
      @Test
      public void instancesShouldBeEqualAfterDeserializing()
      {
          // Set up
          final ReferenceKey key = ReferenceKey.KEY;
  
          // Invoke
          final Object roundTrippedKey = deserialize(serialize(key));
  
          // Check
          assertEquals(key, roundTrippedKey);
          assertEquals(key.hashCode(), roundTrippedKey.hashCode());
          assertNotSame(key, roundTrippedKey);
      }
  }