Added a unit test for CopyState

Signed-off-by: Kartik Ganesh <[email protected]>

Author: kartg

server/src/test/java/org/opensearch/indices/replication/common/CopyStateTests.java

@@ -0,0 +1,79 @@
+/*
+ * 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.indices.replication.common;
+
+import org.apache.lucene.index.IndexCommit;
+import org.apache.lucene.index.IndexFileNames;
+import org.apache.lucene.index.SegmentInfos;
+import org.apache.lucene.util.Version;
+import org.opensearch.common.collect.Map;
+import org.opensearch.common.concurrent.GatedCloseable;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.index.shard.IndexShardTestCase;
+import org.opensearch.index.shard.ShardId;
+import org.opensearch.index.store.Store;
+import org.opensearch.index.store.StoreFileMetadata;
+import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
+
+import java.io.IOException;
+import java.util.Set;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class CopyStateTests extends IndexShardTestCase {
+
+    public void testCopyStateCreation() throws IOException {
+        // dummy objects setup
+        final long expectedLongValue = 1L;
+        final ShardId testShardId = new ShardId("testIndex", "testUUID", 0);
+        final StoreFileMetadata segmentsFile = new StoreFileMetadata(IndexFileNames.SEGMENTS, 1L, "0", Version.LATEST);
+        final StoreFileMetadata pendingDeleteFile = new StoreFileMetadata("pendingDelete.del", 1L, "1", Version.LATEST);
+        final Store.MetadataSnapshot commitMetadataSnapshot = new Store.MetadataSnapshot(
+            Map.of("segmentsFile", segmentsFile, "pendingDeleteFile", pendingDeleteFile),
+            null,
+            0
+        );
+        final Store.MetadataSnapshot segmentInfosMetadataSnapshot = new Store.MetadataSnapshot(
+            Map.of("segmentsFile", segmentsFile),
+            null,
+            0
+        );
+
+        // Mock objects setup
+        IndexShard mockShard = mock(IndexShard.class);
+        when(mockShard.shardId()).thenReturn(testShardId);
+        when(mockShard.getOperationPrimaryTerm()).thenReturn(expectedLongValue);
+        when(mockShard.getProcessedLocalCheckpoint()).thenReturn(expectedLongValue);
+
+        Store mockStore = mock(Store.class);
+        when(mockShard.store()).thenReturn(mockStore);
+
+        SegmentInfos testSegmentInfos = new SegmentInfos(Version.LATEST.major);
+        when(mockShard.getSegmentInfosSnapshot()).thenReturn(new GatedCloseable<>(testSegmentInfos, () -> {}));
+
+        when(mockStore.getMetadata(testSegmentInfos)).thenReturn(segmentInfosMetadataSnapshot);
+
+        IndexCommit mockIndexCommit = mock(IndexCommit.class);
+        when(mockShard.acquireLastIndexCommit(false)).thenReturn(new GatedCloseable<>(mockIndexCommit, () -> {}));
+        when(mockStore.getMetadata(mockIndexCommit)).thenReturn(commitMetadataSnapshot);
+
+        // unit test
+        CopyState copyState = new CopyState(mockShard);
+        ReplicationCheckpoint checkpoint = copyState.getCheckpoint();
+        assertEquals(testShardId, checkpoint.getShardId());
+        // version was never set so this should be zero
+        assertEquals(0, checkpoint.getSegmentInfosVersion());
+        assertEquals(expectedLongValue, checkpoint.getPrimaryTerm());
+
+        Set<StoreFileMetadata> pendingDeleteFiles = copyState.getPendingDeleteFiles();
+        assertEquals(1, pendingDeleteFiles.size());
+        assertTrue(pendingDeleteFiles.contains(pendingDeleteFile));
+    }
+}