Add test

Author: pawankartik-elastic

server/src/internalClusterTest/java/org/elasticsearch/action/admin/cluster/stats/CpsClusterStatsShouldNotExposeSkipUnavailableIT.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.action.admin.cluster.stats;
+
+import org.elasticsearch.common.settings.Setting;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.CollectionUtils;
+import org.elasticsearch.plugins.ClusterPlugin;
+import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.test.AbstractMultiClustersTestCase;
+import org.hamcrest.Matchers;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertResponse;
+
+// TODO: Move this test to the Serverless repo once the IT framework is ready there.
+public class CpsClusterStatsShouldNotExposeSkipUnavailableIT extends AbstractMultiClustersTestCase {
+    private static final String LINKED_CLUSTER_1 = "cluster-a";
+
+    public static class CpsPlugin extends Plugin implements ClusterPlugin {
+        @Override
+        public List<Setting<?>> getSettings() {
+            return List.of(CpsEnableSetting);
+        }
+    }
+
+    private static final Setting<String> CpsEnableSetting = Setting.simpleString(
+        "serverless.cross_project.enabled",
+        Setting.Property.NodeScope
+    );
+
+    @Override
+    protected List<String> remoteClusterAlias() {
+        return List.of(LINKED_CLUSTER_1);
+    }
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins(String clusterAlias) {
+        return CollectionUtils.appendToCopy(super.nodePlugins(clusterAlias), CpsPlugin.class);
+    }
+
+    @Override
+    protected Settings nodeSettings() {
+        return Settings.builder().put(super.nodeSettings()).put("serverless.cross_project.enabled", "true").build();
+    }
+
+    @Override
+    protected Map<String, Boolean> skipUnavailableForRemoteClusters() {
+        return Map.of(LINKED_CLUSTER_1, randomBoolean());
+    }
+
+    public void testSkipUnavailableShouldNotBeExposed() throws Exception {
+        assertResponse(
+            client().execute(TransportClusterStatsAction.TYPE, new ClusterStatsRequest(/* Do include remotes */ true)),
+            result -> {
+                // In CPS environment, skip_unavailable should map to `Optional.empty()`.
+                assertThat(result.getRemoteClustersStats().get(LINKED_CLUSTER_1).skipUnavailable(), Matchers.is(Optional.empty()));
+                // When this result is serialised to JSON, it should not mention `skip_unavailable`.
+                assertThat(result.toString().contains("skip_unavailable"), Matchers.is(false));
+            }
+        );
+    }
+}