[TEST] Add back necessary tests for deprecated settings that are replaced during applying inclusive naming

server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/stats/ClusterStatsIT.java

@@ -51,6 +51,7 @@
 import org.hamcrest.Matchers;
 
 import java.io.IOException;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -144,6 +145,28 @@ public void testNodeCounts() {
         }
     }
 
+    // Validate assigning value "master" to setting "node.roles" can get correct count in Node Stats response after MASTER_ROLE deprecated.
+    // TODO: Remove the test after removing MASTER_ROLE.
+    public void testNodeCountsWithDeprecatedMasterRole() {
+        int total = 1;
+        Settings settings = Settings.builder()
+            .putList(NodeRoleSettings.NODE_ROLES_SETTING.getKey(), Collections.singletonList(DiscoveryNodeRole.MASTER_ROLE.roleName()))
+            .build();
+        internalCluster().startNode(settings);
+        waitForNodes(total);
+
+        Map<String, Integer> expectedCounts = new HashMap<>();
+        expectedCounts.put(DiscoveryNodeRole.DATA_ROLE.roleName(), 0);
+        expectedCounts.put(DiscoveryNodeRole.MASTER_ROLE.roleName(), 1);
+        expectedCounts.put(DiscoveryNodeRole.CLUSTER_MANAGER_ROLE.roleName(), 1);
+        expectedCounts.put(DiscoveryNodeRole.INGEST_ROLE.roleName(), 0);
+        expectedCounts.put(DiscoveryNodeRole.REMOTE_CLUSTER_CLIENT_ROLE.roleName(), 0);
+        expectedCounts.put(ClusterStatsNodes.Counts.COORDINATING_ONLY, 0);
+
+        ClusterStatsResponse response = client().admin().cluster().prepareClusterStats().get();
+        assertCounts(response.getNodesStats().getCounts(), total, expectedCounts);
+    }
+
     private static void incrementCountForRole(String role, Map<String, Integer> counts) {
         Integer count = counts.get(role);
         if (count == null) {

server/src/test/java/org/opensearch/action/admin/cluster/configuration/AddVotingConfigExclusionsRequestTests.java

@@ -450,6 +450,65 @@ public void testResolveAndCheckMaximum() {
         assertWarnings(AddVotingConfigExclusionsRequest.DEPRECATION_MESSAGE);
     }
 
+    // As of 2.0, MASTER_ROLE is deprecated to promote inclusive language.
+    // Validate node with MASTER_ROLE can be resolved by resolveVotingConfigExclusions() like before.
+    // TODO: Remove the test after removing MASTER_ROLE.
+    public void testResolveByNodeDescriptionWithDeprecatedMasterRole() {
+        final DiscoveryNode localNode = new DiscoveryNode(
+            "local",
+            "local",
+            buildNewFakeTransportAddress(),
+            emptyMap(),
+            singleton(DiscoveryNodeRole.MASTER_ROLE),
+            Version.CURRENT
+        );
+        final VotingConfigExclusion localNodeExclusion = new VotingConfigExclusion(localNode);
+
+        final ClusterState clusterState = ClusterState.builder(new ClusterName("cluster"))
+            .nodes(new Builder().add(localNode).localNodeId(localNode.getId()))
+            .build();
+
+        assertThat(makeRequestWithNodeDescriptions("_local").resolveVotingConfigExclusions(clusterState), contains(localNodeExclusion));
+        assertWarnings(AddVotingConfigExclusionsRequest.DEPRECATION_MESSAGE);
+    }
+
+    // TODO: Remove the test after removing MASTER_ROLE.
+    public void testResolveByNodeIdWithDeprecatedMasterRole() {
+        final DiscoveryNode node = new DiscoveryNode(
+            "nodeName",
+            "nodeId",
+            buildNewFakeTransportAddress(),
+            emptyMap(),
+            singleton(DiscoveryNodeRole.MASTER_ROLE),
+            Version.CURRENT
+        );
+        final VotingConfigExclusion nodeExclusion = new VotingConfigExclusion(node);
+
+        final ClusterState clusterState = ClusterState.builder(new ClusterName("cluster")).nodes(new Builder().add(node)).build();
+
+        assertThat(
+            new AddVotingConfigExclusionsRequest(Strings.EMPTY_ARRAY, new String[] { "nodeId" }, Strings.EMPTY_ARRAY, TimeValue.ZERO)
+                .resolveVotingConfigExclusions(clusterState),
+            contains(nodeExclusion)
+        );
+    }
+
+    public void testResolveByNodeNameWithDeprecatedMasterRole() {
+        final DiscoveryNode node = new DiscoveryNode(
+            "nodeName",
+            "nodeId",
+            buildNewFakeTransportAddress(),
+            emptyMap(),
+            singleton(DiscoveryNodeRole.MASTER_ROLE),
+            Version.CURRENT
+        );
+        final VotingConfigExclusion nodeExclusion = new VotingConfigExclusion(node);
+
+        final ClusterState clusterState = ClusterState.builder(new ClusterName("cluster")).nodes(new Builder().add(node)).build();
+
+        assertThat(new AddVotingConfigExclusionsRequest("nodeName").resolveVotingConfigExclusions(clusterState), contains(nodeExclusion));
+    }
+
     private static AddVotingConfigExclusionsRequest makeRequestWithNodeDescriptions(String... nodeDescriptions) {
         return new AddVotingConfigExclusionsRequest(
             nodeDescriptions,

server/src/test/java/org/opensearch/action/support/master/TransportMasterNodeActionTests.java

@@ -525,4 +525,41 @@ protected void masterOperation(Request request, ClusterState state, ActionListen
         assertTrue(listener.isDone());
         assertThat(listener.get(), equalTo(response));
     }
+
+    // Validate TransportMasterNodeAction.testDelegateToMaster() works correctly on node with the deprecated MASTER_ROLE.
+    // TODO: Remove the test after removing MASTER_ROLE.
+    public void testDelegateToMasterOnNodeWithDeprecatedMasterRole() throws ExecutionException, InterruptedException {
+        DiscoveryNode localNode = new DiscoveryNode(
+            "local_node",
+            buildNewFakeTransportAddress(),
+            Collections.emptyMap(),
+            Collections.singleton(DiscoveryNodeRole.MASTER_ROLE),
+            Version.CURRENT
+        );
+        DiscoveryNode remoteNode = new DiscoveryNode(
+            "remote_node",
+            buildNewFakeTransportAddress(),
+            Collections.emptyMap(),
+            Collections.singleton(DiscoveryNodeRole.MASTER_ROLE),
+            Version.CURRENT
+        );
+        DiscoveryNode[] allNodes = new DiscoveryNode[] { localNode, remoteNode };
+
+        Request request = new Request();
+        setState(clusterService, ClusterStateCreationUtils.state(localNode, remoteNode, allNodes));
+
+        PlainActionFuture<Response> listener = new PlainActionFuture<>();
+        new Action("internal:testAction", transportService, clusterService, threadPool).execute(request, listener);
+
+        assertThat(transport.capturedRequests().length, equalTo(1));
+        CapturingTransport.CapturedRequest capturedRequest = transport.capturedRequests()[0];
+        assertTrue(capturedRequest.node.isMasterNode());
+        assertThat(capturedRequest.request, equalTo(request));
+        assertThat(capturedRequest.action, equalTo("internal:testAction"));
+
+        Response response = new Response();
+        transport.handleResponse(capturedRequest.requestId, response);
+        assertTrue(listener.isDone());
+        assertThat(listener.get(), equalTo(response));
+    }
 }

server/src/test/java/org/opensearch/cluster/ClusterChangedEventTests.java

@@ -314,6 +314,36 @@ public void testChangedCustomMetadataSet() {
         assertTrue(changedCustomMetadataTypeSet.contains(customMetadata1.getWriteableName()));
     }
 
+    // Validate the above test case testLocalNodeIsMaster() passes when the deprecated 'master' role is assigned to the local node.
+    // TODO: Remove the test after removing MASTER_ROLE.
+    public void testLocalNodeIsMasterWithDeprecatedMasterRole() {
+        final DiscoveryNodes.Builder builderLocalIsMaster = DiscoveryNodes.builder();
+        final DiscoveryNode node0 = newNode("node_0", Set.of(DiscoveryNodeRole.MASTER_ROLE));
+        final DiscoveryNode node1 = newNode("node_1", Set.of(DiscoveryNodeRole.DATA_ROLE));
+        builderLocalIsMaster.add(node0).add(node1).masterNodeId(node0.getId()).localNodeId(node0.getId());
+
+        final DiscoveryNodes.Builder builderLocalNotMaster = DiscoveryNodes.builder();
+        builderLocalNotMaster.add(node0).add(node1).masterNodeId(node0.getId()).localNodeId(node1.getId());
+
+        ClusterState previousState = createSimpleClusterState();
+        final Metadata metadata = createMetadata(initialIndices);
+        ClusterState newState = ClusterState.builder(TEST_CLUSTER_NAME)
+            .nodes(builderLocalIsMaster.build())
+            .metadata(metadata)
+            .routingTable(createRoutingTable(1, metadata))
+            .build();
+        ClusterChangedEvent event = new ClusterChangedEvent("_na_", newState, previousState);
+        assertTrue("local node should be master", event.localNodeMaster());
+
+        newState = ClusterState.builder(TEST_CLUSTER_NAME)
+            .nodes(builderLocalNotMaster.build())
+            .metadata(metadata)
+            .routingTable(createRoutingTable(1, metadata))
+            .build();
+        event = new ClusterChangedEvent("_na_", newState, previousState);
+        assertFalse("local node should not be master", event.localNodeMaster());
+    }
+
     private static class CustomMetadata2 extends TestCustomMetadata {
         protected CustomMetadata2(String data) {
             super(data);