Compute matrix diagonal on normalization #252 (#304)

* Compute matrix diagonal on normalization #252

src/main/java/org/rulez/demokracia/pdengine/BeatTable.java

@@ -6,7 +6,7 @@
 import org.rulez.demokracia.pdengine.dataobjects.Pair;
 import org.rulez.demokracia.types.MapMatrix;
 
-public class BeatTable extends MapMatrix<String, Pair> implements TransitiveClosable {
+public class BeatTable extends MapMatrix<String, Pair> implements TransitiveClosable, Normalizable {
 	private static final long serialVersionUID = 1L;
 
 	public enum Direction {

src/main/java/org/rulez/demokracia/pdengine/Normalizable.java

@@ -0,0 +1,14 @@
+package org.rulez.demokracia.pdengine;
+import org.rulez.demokracia.pdengine.dataobjects.Pair;
+
+public interface Normalizable extends ContainingBeats {
+
+	long serialVersionUID = 1L;
+
+	default void normalize() {
+		for (String key : getKeyCollection()) {
+			setElement(key, key, new Pair(0, 0));
+		}
+	}
+
+}

src/main/java/org/rulez/demokracia/pdengine/dataobjects/PairEntity.java

@@ -3,7 +3,7 @@
 import org.rulez.demokracia.pdengine.persistence.BaseEntity;
 
 public class PairEntity extends BaseEntity {
-	
+
 	private static final long serialVersionUID = 1L;
 	public int winning;
 	public int losing;

src/main/java/org/rulez/demokracia/pdengine/persistence/BaseEntity.java

@@ -7,19 +7,30 @@
 import javax.persistence.Inheritance;
 import javax.persistence.InheritanceType;
 
+import org.apache.commons.lang3.builder.EqualsBuilder;
+import org.apache.commons.lang3.builder.HashCodeBuilder;
 import org.rulez.demokracia.pdengine.RandomUtils;
 
 @Entity
 @Inheritance(strategy = InheritanceType.JOINED)
 public abstract class BaseEntity implements Serializable {
 
 	private static final long serialVersionUID = 1L;
-	
+
 	@Id
 	public String id;
-
-    public BaseEntity() {
-    	id = RandomUtils.createRandomKey();
-    }
-
+
+	public BaseEntity() {
+		id = RandomUtils.createRandomKey();
+	}
+
+	@Override
+	public int hashCode() {
+		return HashCodeBuilder.reflectionHashCode(this, "id");
+	}
+
+	@Override
+	public boolean equals(final Object other) {
+		return EqualsBuilder.reflectionEquals(this, other, "id");
+	}
 }

src/test/java/org/rulez/demokracia/pdengine/BaseEntityHashEqualsTest.java

@@ -0,0 +1,47 @@
+package org.rulez.demokracia.pdengine;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+import org.junit.Test;
+import org.rulez.demokracia.pdengine.annotations.TestedBehaviour;
+import org.rulez.demokracia.pdengine.annotations.TestedFeature;
+import org.rulez.demokracia.pdengine.annotations.TestedOperation;
+import org.rulez.demokracia.pdengine.dataobjects.Pair;
+import org.rulez.demokracia.pdengine.dataobjects.VoteEntity;
+
+@TestedFeature("Supporting functionality")
+@TestedOperation("BaseEntity")
+@TestedBehaviour("None of the entities count id into the equals and hashCode.")
+public class BaseEntityHashEqualsTest {
+
+
+	@Test
+	public void entities_with_equal_fields_are_equal() {
+		Pair pair1 = new Pair(12, 42);
+		Pair pair2 = new Pair(12, 42);
+		assertNotEquals(pair1.id, pair2.id);
+		assertEquals(pair1, pair2);
+	}
+
+	@Test
+	public void entities_with_different_fields_are_not_equal() {
+		Pair pair1 = new Pair(12, 42);
+		Pair pair2 = new Pair(12, 69);
+		assertNotEquals(pair1, pair2);
+	}
+
+	@Test
+	public void equal_entities_have_the_same_hash_code() {
+		Pair pair1 = new Pair(12, 42);
+		Pair pair2 = new Pair(12, 42);
+		assertEquals(pair1.hashCode(), pair2.hashCode());
+	}
+
+	@Test
+	public void hashCode_should_return_different_hash_on_different_entities() {
+		Pair pair = new Pair(10, 10);
+		VoteEntity vote = new VoteEntity();
+		assertNotEquals(pair.hashCode(), vote.hashCode());
+	}
+}

src/test/java/org/rulez/demokracia/pdengine/BeatTableNormalizationTest.java

@@ -0,0 +1,36 @@
+package org.rulez.demokracia.pdengine;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.rulez.demokracia.pdengine.annotations.TestedBehaviour;
+import org.rulez.demokracia.pdengine.annotations.TestedFeature;
+import org.rulez.demokracia.pdengine.annotations.TestedOperation;
+import org.rulez.demokracia.pdengine.dataobjects.Pair;
+import org.rulez.demokracia.pdengine.exception.ReportedException;
+import org.rulez.demokracia.pdengine.testhelpers.CreatedBeatTable;
+
+@TestedFeature("Schulze method")
+@TestedOperation("normalize beat matrix")
+public class BeatTableNormalizationTest extends CreatedBeatTable {
+
+	@Override
+	@Before
+	public void setUp() throws ReportedException {
+		super.setUp();
+		createNewBeatTableWithComplexData();
+	}
+
+	@TestedBehaviour("the diagonal elements are (0,0)")
+	@Test
+	public void normalization_sets_the_diagonal_to_0_0() {
+		beatTable.normalize();
+		beatTable.getKeyCollection().forEach(k -> assertDiagonalElementIsZero(k));
+	}
+
+	private void assertDiagonalElementIsZero(final String key) {
+		Pair element = beatTable.getElement(key, key);
+		assertEquals(new Pair(0, 0), element);
+	}
+}