Adding unit tests

Signed-off-by: kh3ra <adityakh3ra@gmail.com>

Author: kh3ra

server/src/test/java/org/opensearch/index/merge/MergedSegmentReplicationTrackerTests.java

@@ -0,0 +1,87 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.merge;
+
+import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.index.IndexSettings;
+import org.opensearch.test.OpenSearchTestCase;
+
+import static org.opensearch.common.settings.Settings.builder;
+
+public class MergedSegmentReplicationTrackerTests extends OpenSearchTestCase {
+
+    private MergedSegmentReplicationTracker tracker;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        ShardId shardId = new ShardId("test", "uuid", 0);
+        IndexSettings indexSettings = new IndexSettings(
+            newIndexMeta("test", builder().build()),
+            builder().build()
+        );
+        tracker = new MergedSegmentReplicationTracker(shardId, indexSettings);
+    }
+
+    public void testInitialStats() {
+        MergedSegmentWarmerStats stats = tracker.stats();
+        assertEquals(0, stats.getTotalWarmInvocationsCount());
+        assertEquals(0, stats.getTotalWarmTimeMillis());
+        assertEquals(0, stats.getTotalWarmFailureCount());
+        assertEquals(0, stats.getTotalBytesUploaded());
+        assertEquals(0, stats.getTotalBytesDownloaded());
+        assertEquals(0, stats.getTotalUploadTimeMillis());
+        assertEquals(0, stats.getTotalDownloadTimeMillis());
+        assertEquals(0, stats.getOngoingWarms());
+    }
+
+    public void testIncrementCounters() {
+        tracker.incrementTotalWarmInvocationsCount();
+        tracker.incrementTotalWarmFailureCount();
+        tracker.incrementTotalRejectedWarms();
+        
+        MergedSegmentWarmerStats stats = tracker.stats();
+        assertEquals(1, stats.getTotalWarmInvocationsCount());
+        assertEquals(1, stats.getTotalWarmFailureCount());
+    }
+
+    public void testOngoingWarms() {
+        tracker.incrementOngoingWarms();
+        tracker.incrementOngoingWarms();
+        assertEquals(2, tracker.stats().getOngoingWarms());
+        
+        tracker.decrementOngoingWarms();
+        assertEquals(1, tracker.stats().getOngoingWarms());
+    }
+
+    public void testAddTimeAndBytes() {
+        tracker.addTotalWarmTimeMillis(100);
+        tracker.addTotalUploadTimeMillis(200);
+        tracker.addTotalDownloadTimeMillis(300);
+        tracker.addTotalBytesUploaded(1024);
+        tracker.addTotalBytesDownloaded(2048);
+        
+        MergedSegmentWarmerStats stats = tracker.stats();
+        assertEquals(100, stats.getTotalWarmTimeMillis());
+        assertEquals(200, stats.getTotalUploadTimeMillis());
+        assertEquals(300, stats.getTotalDownloadTimeMillis());
+        assertEquals(1024, stats.getTotalBytesUploaded());
+        assertEquals(2048, stats.getTotalBytesDownloaded());
+    }
+
+    public void testAccumulativeStats() {
+        tracker.addTotalWarmTimeMillis(100);
+        tracker.addTotalWarmTimeMillis(50);
+        assertEquals(150, tracker.stats().getTotalWarmTimeMillis());
+        
+        tracker.addTotalBytesUploaded(1000);
+        tracker.addTotalBytesUploaded(500);
+        assertEquals(1500, tracker.stats().getTotalBytesUploaded());
+    }
+}