Add unit tests

Author: vishesh92

api/src/main/java/org/apache/cloudstack/cluster/ClusterDrsAlgorithm.java

@@ -117,7 +117,7 @@ default Double getImbalancePostMigration(ServiceOffering serviceOffering, Virtua
     private Pair<Long, Map<Long, Ternary<Long, Long, Long>>> getHostMetricsMapAndType(Long clusterId,
             ServiceOffering serviceOffering, Map<Long, Ternary<Long, Long, Long>> hostCpuMap,
             Map<Long, Ternary<Long, Long, Long>> hostMemoryMap) throws ConfigurationException {
-        String metric = ClusterDrsMetric.valueIn(clusterId);
+        String metric = getClusterDrsMetric(clusterId);
         Pair<Long, Map<Long, Ternary<Long, Long, Long>>> pair;
         switch (metric) {
             case "cpu":
@@ -155,22 +155,26 @@ private Double getImbalance(List<Double> metricList) {
         return clusterStandardDeviation / clusterMeanMetric;
     }
 
-    private Double getMetricValue(Long clusterId, double used, double free, double total, Float skipThreshold) {
-        boolean useRatio = ClusterDrsMetricUseRatio.valueIn(clusterId);
-        switch (ClusterDrsMetricType.valueIn(clusterId)) {
+    default String getClusterDrsMetric(long clusterId) {
+        return ClusterDrsMetric.valueIn(clusterId);
+    }
+
+    default Double getMetricValue(long clusterId, long used, long free, long total, Float skipThreshold) {
+        boolean useRatio = getDrsMetricUseRatio(clusterId);
+        switch (getDrsMetricType(clusterId)) {
             case "free":
                 if (skipThreshold != null && free < skipThreshold * total) return null;
                 if (useRatio) {
-                    return free / total;
+                    return (double) free / total;
                 } else {
-                    return free;
+                    return (double) free;
                 }
             case "used":
                 if (skipThreshold != null && used > skipThreshold * total) return null;
                 if (useRatio) {
-                    return used / total;
+                    return (double) used / total;
                 } else {
-                    return used;
+                    return (double) used;
                 }
         }
         return null;
@@ -206,6 +210,14 @@ default Double getClusterStandardDeviation(List<Double> metricList, Double mean)
         }
     }
 
+    default boolean getDrsMetricUseRatio(long clusterId) {
+        return ClusterDrsMetricUseRatio.valueIn(clusterId);
+    }
+
+    default String getDrsMetricType(long clusterId) {
+        return ClusterDrsMetricType.valueIn(clusterId);
+    }
+
     /**
      * The cluster imbalance is defined as the percentage deviation from the mean
      * for a configured metric of the cluster. The standard deviation is used as a
@@ -218,7 +230,7 @@ default Double getClusterStandardDeviation(List<Double> metricList, Double mean)
      */
     default Double getClusterImbalance(Long clusterId, List<Ternary<Long, Long, Long>> cpuList,
             List<Ternary<Long, Long, Long>> memoryList, Float skipThreshold) throws ConfigurationException {
-        String metric = ClusterDrsMetric.valueIn(clusterId);
+        String metric = getClusterDrsMetric(clusterId);
         List<Double> list;
         switch (metric) {
             case "cpu":

api/src/test/java/org/apache/cloudstack/cluster/ClusterDrsAlgorithmTest.java

@@ -0,0 +1,89 @@
+/*
+ * 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.cloudstack.cluster;
+
+import com.cloud.utils.Ternary;
+import junit.framework.TestCase;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Spy;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.util.List;
+
+import static org.mockito.Mockito.doReturn;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ClusterDrsAlgorithmTest extends TestCase {
+
+    @Spy
+    ClusterDrsAlgorithm drsAlgorithm;
+
+    @Test
+    public void testGetMetricValue() {
+        List<Ternary<Boolean, String, Double>> testData = List.of(
+                new Ternary<>(true, "free", 0.4),
+                new Ternary<>(false, "free", 40.0),
+                new Ternary<>(true, "used", 0.3),
+                new Ternary<>(false, "used", 30.0)
+        );
+
+        long used = 30;
+        long free = 40;
+        long total = 100;
+
+        for (Ternary<Boolean, String, Double> data : testData) {
+            boolean useRatio = data.first();
+            String metricType = data.second();
+            double expectedValue = data.third();
+
+            doReturn(useRatio).when(drsAlgorithm).getDrsMetricUseRatio(1L);
+            doReturn(metricType).when(drsAlgorithm).getDrsMetricType(1L);
+
+            assertEquals(expectedValue, drsAlgorithm.getMetricValue(1, used, free, total, null));
+        }
+    }
+
+    @Test
+    public void testGetMetricValueWithSkipThreshold() {
+        List<Ternary<Boolean, String, Double>> testData = List.of(
+                new Ternary<>(true, "free", 0.15),
+                new Ternary<>(false, "free", 15.0),
+                new Ternary<>(true, "used", null),
+                new Ternary<>(false, "used", null)
+        );
+
+        long used = 80;
+        long free = 15;
+        long total = 100;
+
+        for (Ternary<Boolean, String, Double> data : testData) {
+            boolean useRatio = data.first();
+            String metricType = data.second();
+            Double expectedValue = data.third();
+            float skipThreshold = metricType.equals("free") ? 0.1f : 0.7f;
+
+            doReturn(useRatio).when(drsAlgorithm).getDrsMetricUseRatio(1L);
+            doReturn(metricType).when(drsAlgorithm).getDrsMetricType(1L);
+
+            assertEquals(expectedValue, drsAlgorithm.getMetricValue(1L, used, free, total, skipThreshold));
+        }
+    }
+}