/**
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements. See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership. The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *     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,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.rdf.api;
  
  import org.junit.Test;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotEquals;
  
  /**
   * Abstract test class for the BlankNode interface.
   */
  public abstract class AbstractBlankNodeTest {
  
      /**
       * This method must be overridden by the implementing test to create a
       * {@link BlankNode} to be tested.
       * <p>
       * Each call to this method must provide a new, unique BlankNode.
       *
       * @return {@link RDF} instance to be tested.
       */
      protected abstract BlankNode getBlankNode();
  
      /**
       * Gets a new blank node object based on the given identifier.
       * <p>
       * Subsequent calls to this method during a single test with the same
       * identifier must return BlankNode objects that are equals and have the
       * same hashCode. The objects returned from successive calls during a single
       * test may be the same object, or they may be different objects.
       * </p>
       *
       * @param identifier
       *            The identifier to use as the reference for creating the blank
       *            node that is returned.
       * @return A new blank node based on the
       */
      protected abstract BlankNode getBlankNode(String identifier);
  
      /**
       * Test method for {@link BlankNode#uniqueReference()}.
       */
      @Test
      public final void testInternalIdentifier() {
          final BlankNode testNull = new BlankNode() {
              @Override
              public String ntriplesString() {
                  return null;
              }
  
              @Override
              public String uniqueReference() {
                  return null;
              }
          };
          final BlankNode testAutomatic1 = getBlankNode();
          final BlankNode testAutomatic2 = getBlankNode();
          final BlankNode testManual3a = getBlankNode("3");
          final BlankNode testManual3b = getBlankNode("3");
          final BlankNode testManual4 = getBlankNode("4");
  
          // Test against our fake stub
          assertNotEquals(testNull.uniqueReference(), testAutomatic1.uniqueReference());
          assertNotEquals(testAutomatic1.uniqueReference(), testNull.uniqueReference());
          assertNotEquals(testNull.uniqueReference(), testManual3a.uniqueReference());
          assertNotEquals(testManual3a.uniqueReference(), testNull.uniqueReference());
  
          // Test the two imported instances against each other
          assertEquals(testAutomatic1.uniqueReference(), testAutomatic1.uniqueReference());
          assertEquals(testAutomatic2.uniqueReference(), testAutomatic2.uniqueReference());
          assertNotEquals(testAutomatic1.uniqueReference(), testAutomatic2.uniqueReference());
          assertNotEquals(testAutomatic2.uniqueReference(), testAutomatic1.uniqueReference());
          assertNotEquals(testAutomatic1.uniqueReference(), testManual3a.uniqueReference());
          assertEquals(testManual3b.uniqueReference(), testManual3a.uniqueReference());
          assertNotEquals(testManual3a.uniqueReference(), testManual4.uniqueReference());
      }
  
      /**
       * Test method for {@link BlankNode#equals(java.lang.Object)}.
       */
      @Test
      public final void testEquals() {
          final BlankNode testNull = new BlankNode() {
             @Override
             public String ntriplesString() {
                 return null;
             }
 
             @Override
             public String uniqueReference() {
                 return null;
             }
         };
         final BlankNode testAutomatic1 = getBlankNode();
         final BlankNode testAutomatic2 = getBlankNode();
         final BlankNode testManual3a = getBlankNode("3");
         final BlankNode testManual3b = getBlankNode("3");
         final BlankNode testManual4 = getBlankNode("4");
 
         // Test against our fake stub
         assertNotEquals(testNull, testAutomatic1);
         assertNotEquals(testAutomatic1, testNull);
         assertNotEquals(testNull, testManual3a);
         assertNotEquals(testManual3a, testNull);
 
         // Test the two imported instances against each other
         assertEquals(testAutomatic1, testAutomatic1);
         assertEquals(testAutomatic2, testAutomatic2);
         assertNotEquals(testAutomatic1, testAutomatic2);
         assertNotEquals(testAutomatic2, testAutomatic1);
         assertNotEquals(testAutomatic1, testManual3a);
         assertEquals(testManual3b, testManual3a);
         assertNotEquals(testManual3a, testManual4);
     }
 
     /**
      * Test method for {@link BlankNode#hashCode()}.
      */
     @Test
     public final void testHashCode() {
         final BlankNode testNull = new BlankNode() {
             @Override
             public String ntriplesString() {
                 return null;
             }
 
             @Override
             public String uniqueReference() {
                 return null;
             }
         };
         final BlankNode testAutomatic1 = getBlankNode();
         final BlankNode testAutomatic2 = getBlankNode();
         final BlankNode testManual3a = getBlankNode("3");
         final BlankNode testManual3b = getBlankNode("3");
         final BlankNode testManual4 = getBlankNode("4");
 
         // Test against our fake stub
         assertNotEquals(testNull.hashCode(), testAutomatic1.hashCode());
         assertNotEquals(testAutomatic1.hashCode(), testNull.hashCode());
         assertNotEquals(testNull.hashCode(), testManual3a.hashCode());
         assertNotEquals(testManual3a.hashCode(), testNull.hashCode());
 
         // Test the two imported instances against each other
         assertEquals(testAutomatic1.hashCode(), testAutomatic1.hashCode());
         assertEquals(testAutomatic2.hashCode(), testAutomatic2.hashCode());
         assertNotEquals(testAutomatic1.hashCode(), testAutomatic2.hashCode());
         assertNotEquals(testAutomatic2.hashCode(), testAutomatic1.hashCode());
         assertNotEquals(testAutomatic1.hashCode(), testManual3a.hashCode());
         assertEquals(testManual3b.hashCode(), testManual3a.hashCode());
         assertNotEquals(testManual3a.hashCode(), testManual4.hashCode());
     }
 
     /**
      * Test method for {@link RDFTerm#ntriplesString()}.
      */
     @Test
     public final void testNtriplesString() {
         final BlankNode testNull = new BlankNode() {
             @Override
             public String ntriplesString() {
                 return null;
             }
 
             @Override
             public String uniqueReference() {
                 return null;
             }
         };
         final BlankNode testAutomatic1 = getBlankNode();
         final BlankNode testAutomatic2 = getBlankNode();
         final BlankNode testManual3a = getBlankNode("3");
         final BlankNode testManual3b = getBlankNode("3");
         final BlankNode testManual4 = getBlankNode("4");
 
         // Test against our fake stub
         assertNotEquals(testNull.ntriplesString(), testAutomatic1.ntriplesString());
         assertNotEquals(testAutomatic1.ntriplesString(), testNull.ntriplesString());
         assertNotEquals(testNull.ntriplesString(), testManual3a.ntriplesString());
         assertNotEquals(testManual3a.ntriplesString(), testNull.ntriplesString());
 
         // Test the two imported instances against each other
         assertEquals(testAutomatic1.ntriplesString(), testAutomatic1.ntriplesString());
         assertEquals(testAutomatic2.ntriplesString(), testAutomatic2.ntriplesString());
         assertNotEquals(testAutomatic1.ntriplesString(), testAutomatic2.ntriplesString());
         assertNotEquals(testAutomatic2.ntriplesString(), testAutomatic1.ntriplesString());
         assertNotEquals(testAutomatic1.ntriplesString(), testManual3a.ntriplesString());
         assertEquals(testManual3b.ntriplesString(), testManual3a.ntriplesString());
         assertNotEquals(testManual3a.ntriplesString(), testManual4.ntriplesString());
     }
 
 }