Added test for default methods in DiscreteDistribution
diff --git a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/DiscreteDistributionTest.java b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/DiscreteDistributionTest.java
new file mode 100644
index 0000000..8c44a0e
--- /dev/null
+++ b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/DiscreteDistributionTest.java
@@ -0,0 +1,80 @@
+/*
+ * 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.statistics.distribution;
+
+import org.apache.commons.rng.UniformRandomProvider;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test default implementations in the {@link DiscreteDistribution} interface.
+ */
+public class DiscreteDistributionTest {
+ /**
+ * Test the default interface methods
+ */
+ @Test
+ public void testDefaultMethods() {
+ final DiscreteDistribution dist = new DiscreteDistribution() {
+ @Override
+ public double probability(int x) {
+ return x;
+ }
+ @Override
+ public double probability(int x0, int x1) {
+ return 0;
+ }
+ @Override
+ public double cumulativeProbability(int x) {
+ return 0;
+ }
+ @Override
+ public int inverseCumulativeProbability(double p) {
+ return 0;
+ }
+ @Override
+ public double getMean() {
+ return 0;
+ }
+ @Override
+ public double getVariance() {
+ return 0;
+ }
+ @Override
+ public int getSupportLowerBound() {
+ return 0;
+ }
+ @Override
+ public int getSupportUpperBound() {
+ return 0;
+ }
+ @Override
+ public boolean isSupportConnected() {
+ return false;
+ }
+ @Override
+ public Sampler createSampler(UniformRandomProvider rng) {
+ return null;
+ }
+ };
+
+ for (final int x : new int[] {Integer.MIN_VALUE, -1, 0, 1, 2, Integer.MAX_VALUE}) {
+ // Return the log of the density
+ Assertions.assertEquals(Math.log(x), dist.logProbability(x));
+ }
+ }
+}
