add IT for flow agent with CatIndexTool (opensearch-project#2425) (opensearch-project#2447)

Signed-off-by: Jing Zhang <jngz@amazon.com>
(cherry picked from commit d74c623)

Co-authored-by: Jing Zhang <jngz@amazon.com>

Author: opensearch-trigger-bot[bot]

plugin/src/test/java/org/opensearch/ml/rest/RestMLFlowAgentIT.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.ml.rest;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+import org.opensearch.client.Response;
+import org.opensearch.ml.utils.TestHelper;
+
+public class RestMLFlowAgentIT extends MLCommonsRestTestCase {
+
+    public void testAgentCatIndexTool() throws IOException {
+        // Register agent with CatIndexTool.
+        Response response = registerAgentWithCatIndexTool();
+        Map responseMap = parseResponseToMap(response);
+        String agentId = (String) responseMap.get("agent_id");
+        assertNotNull(agentId);
+        assertEquals(20, agentId.length());
+
+        // Execute agent.
+        response = executeAgentCatIndexTool(agentId);
+        responseMap = parseResponseToMap(response);
+        List responseList = (List) responseMap.get("inference_results");
+        responseMap = (Map) responseList.get(0);
+        responseList = (List) responseMap.get("output");
+        responseMap = (Map) responseList.get(0);
+        assertEquals("response", responseMap.get("name"));
+        String result = (String) responseMap.get("result");
+        assertNotNull(result);
+        assertTrue(result.contains(".plugins-ml-agent"));
+    }
+
+    public static Response registerAgentWithCatIndexTool() throws IOException {
+        String registerAgentEntity = "{\n"
+            + "  \"name\": \"Test_Agent_For_CatIndex_tool\",\n"
+            + "  \"type\": \"flow\",\n"
+            + "  \"description\": \"this is a test agent for the CatIndexTool\",\n"
+            + "  \"tools\": [\n"
+            + "      {\n"
+            + "      \"type\": \"CatIndexTool\",\n"
+            + "      \"name\": \"DemoCatIndexTool\",\n"
+            + "      \"parameters\": {\n"
+            + "        \"input\": \"${parameters.question}\"\n"
+            + "      }\n"
+            + "    }\n"
+            + "  ]\n"
+            + "}";
+        return TestHelper
+            .makeRequest(client(), "POST", "/_plugins/_ml/agents/_register", null, TestHelper.toHttpEntity(registerAgentEntity), null);
+    }
+
+    public static Response executeAgentCatIndexTool(String agentId) throws IOException {
+        String question = "How many indices do I have?";
+        return executeAgent(agentId, question);
+    }
+
+    public static Response executeAgent(String agentId, String question) throws IOException {
+        String executeAgentEntity = "{\n" + "  \"parameters\": {\n" + "    \"question\": \"" + question + "    \"\n" + "  }\n" + "}";
+        return TestHelper
+            .makeRequest(
+                client(),
+                "POST",
+                String.format("/_plugins/_ml/agents/%s/_execute", agentId),
+                null,
+                TestHelper.toHttpEntity(executeAgentEntity),
+                null
+            );
+    }
+}