add tests

Signed-off-by: Ruirui Zhang <mariazrr@amazon.com>

server/src/main/java/org/opensearch/action/admin/cluster/wlm/QueryGroupStatsResponse.java

@@ -49,6 +49,7 @@ protected void writeNodesTo(StreamOutput out, List<QueryGroupStats> nodes) throw
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         for (QueryGroupStats queryGroupStats : getNodes()) {
+            System.out.println(queryGroupStats.getNode().getId());
             builder.startObject(queryGroupStats.getNode().getId());
             queryGroupStats.toXContent(builder, params);
             builder.endObject();

server/src/main/java/org/opensearch/wlm/QueryGroupService.java

@@ -89,7 +89,7 @@ public boolean resourceLimitBreached(String id, QueryGroupState currentState) {
             .anyMatch(
                 entry -> entry.getValue().getLastRecordedUsage() > queryGroup.getMutableQueryGroupFragment()
                     .getResourceLimits()
-                    .get(entry.getKey())
+                    .getOrDefault(entry.getKey(), 0.0)
             );
     }
 

server/src/test/java/org/opensearch/action/admin/cluster/wlm/QueryGroupStatsResponseTests.java

@@ -0,0 +1,108 @@
+/*
+ * 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.action.admin.cluster.wlm;
+
+import org.opensearch.Version;
+import org.opensearch.action.FailedNodeException;
+import org.opensearch.cluster.ClusterName;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.node.DiscoveryNodeRole;
+import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.wlm.ResourceType;
+import org.opensearch.wlm.stats.QueryGroupStats;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class QueryGroupStatsResponseTests extends OpenSearchTestCase {
+    ClusterName clusterName = new ClusterName("test-cluster");
+    String testQueryGroupId = "safjgagnaeekg-3r3fads";
+    DiscoveryNode node = new DiscoveryNode(
+        "node-1",
+        buildNewFakeTransportAddress(),
+        new HashMap<>(),
+        Set.of(DiscoveryNodeRole.DATA_ROLE),
+        Version.CURRENT
+    );
+    Map<String, QueryGroupStats.QueryGroupStatsHolder> statsHolderMap = new HashMap<>();
+    QueryGroupStats queryGroupStats = new QueryGroupStats(
+        node,
+        Map.of(
+            testQueryGroupId,
+            new QueryGroupStats.QueryGroupStatsHolder(
+                0,
+                0,
+                1,
+                0,
+                Map.of(
+                    ResourceType.CPU,
+                    new QueryGroupStats.ResourceStats(0, 0, 0),
+                    ResourceType.MEMORY,
+                    new QueryGroupStats.ResourceStats(0, 0, 0)
+                )
+            )
+        )
+    );
+    List<QueryGroupStats> queryGroupStatsList = List.of(queryGroupStats);
+    List<FailedNodeException> failedNodeExceptionList = new ArrayList<>();
+
+    public void testSerializationAndDeserialization() throws IOException {
+        QueryGroupStatsResponse queryGroupStatsResponse = new QueryGroupStatsResponse(
+            clusterName,
+            queryGroupStatsList,
+            failedNodeExceptionList
+        );
+        BytesStreamOutput out = new BytesStreamOutput();
+        queryGroupStatsResponse.writeTo(out);
+        StreamInput in = out.bytes().streamInput();
+        QueryGroupStatsResponse deserializedResponse = new QueryGroupStatsResponse(in);
+        assertEquals(queryGroupStatsResponse.getClusterName(), deserializedResponse.getClusterName());
+        assertEquals(queryGroupStatsResponse.getNodes().size(), deserializedResponse.getNodes().size());
+    }
+
+    public void testToString() {
+        QueryGroupStatsResponse queryGroupStatsResponse = new QueryGroupStatsResponse(
+            clusterName,
+            queryGroupStatsList,
+            failedNodeExceptionList
+        );
+        String responseString = queryGroupStatsResponse.toString();
+        assertEquals(
+            "{\n"
+                + "  \"node-1\" : {\n"
+                + "    \"query_groups\" : {\n"
+                + "      \"safjgagnaeekg-3r3fads\" : {\n"
+                + "        \"completions\" : 0,\n"
+                + "        \"rejections\" : 0,\n"
+                + "        \"failures\" : 1,\n"
+                + "        \"total_cancellations\" : 0,\n"
+                + "        \"cpu\" : {\n"
+                + "          \"current_usage\" : 0.0,\n"
+                + "          \"cancellations\" : 0,\n"
+                + "          \"rejections\" : 0\n"
+                + "        },\n"
+                + "        \"memory\" : {\n"
+                + "          \"current_usage\" : 0.0,\n"
+                + "          \"cancellations\" : 0,\n"
+                + "          \"rejections\" : 0\n"
+                + "        }\n"
+                + "      }\n"
+                + "    }\n"
+                + "  }\n"
+                + "}",
+            responseString
+        );
+    }
+}

server/src/test/java/org/opensearch/wlm/listeners/QueryGroupRequestOperationListenerTests.java

@@ -8,6 +8,9 @@
 
 package org.opensearch.wlm.listeners;
 
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.metadata.Metadata;
+import org.opensearch.cluster.metadata.QueryGroup;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.util.concurrent.ThreadContext;
@@ -16,6 +19,7 @@
 import org.opensearch.threadpool.TestThreadPool;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TransportService;
+import org.opensearch.wlm.MutableQueryGroupFragment;
 import org.opensearch.wlm.QueryGroupService;
 import org.opensearch.wlm.QueryGroupTask;
 import org.opensearch.wlm.ResourceType;
@@ -97,6 +101,25 @@ public void testValidQueryGroupRequestFailure() throws IOException {
         assertSuccess(testQueryGroupId, queryGroupStateMap, expectedStats, testQueryGroupId);
     }
 
+    public void testResourceLimitBreached() throws IOException {
+        QueryGroup queryGroup = new QueryGroup(
+            "testgroup",
+            new MutableQueryGroupFragment(MutableQueryGroupFragment.ResiliencyMode.MONITOR, Map.of(ResourceType.MEMORY, 0.5))
+        );
+        queryGroupStateMap.put(testQueryGroupId, new QueryGroupState());
+        TransportService mockTransportService = mock(TransportService.class);
+        DiscoveryNode mockDiscoveryNode = mock(DiscoveryNode.class);
+        when(mockTransportService.getLocalNode()).thenReturn(mockDiscoveryNode);
+        ClusterService clusterService = mock(ClusterService.class);
+        ClusterState clusterState = mock(ClusterState.class);
+        when(clusterService.state()).thenReturn(clusterState);
+        Metadata metadata = mock(Metadata.class);
+        when(clusterState.metadata()).thenReturn(metadata);
+        when(metadata.queryGroups()).thenReturn(Map.of(testQueryGroupId, queryGroup));
+        queryGroupService = new QueryGroupService(mockTransportService.getLocalNode(), clusterService, queryGroupStateMap);
+        assertFalse(queryGroupService.resourceLimitBreached(testQueryGroupId, new QueryGroupState()));
+    }
+
     public void testMultiThreadedValidQueryGroupRequestFailures() {
 
         queryGroupStateMap.put(testQueryGroupId, new QueryGroupState());