[TEST] Add validate query tests for empty and malformed queries (#33862)

Relates to #33095

server/src/test/java/org/elasticsearch/rest/action/admin/indices/RestValidateQueryActionTests.java

@@ -0,0 +1,151 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.elasticsearch.rest.action.admin.indices;
+
+import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionListener;
+import org.elasticsearch.action.ActionRequest;
+import org.elasticsearch.action.admin.indices.validate.query.ValidateQueryAction;
+import org.elasticsearch.action.support.ActionFilters;
+import org.elasticsearch.action.support.TransportAction;
+import org.elasticsearch.client.node.NodeClient;
+import org.elasticsearch.common.bytes.BytesArray;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.XContentType;
+import org.elasticsearch.rest.RestController;
+import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.search.AbstractSearchTestCase;
+import org.elasticsearch.tasks.Task;
+import org.elasticsearch.tasks.TaskManager;
+import org.elasticsearch.test.rest.FakeRestChannel;
+import org.elasticsearch.test.rest.FakeRestRequest;
+import org.elasticsearch.threadpool.TestThreadPool;
+import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.usage.UsageService;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.emptySet;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+
+public class RestValidateQueryActionTests extends AbstractSearchTestCase {
+
+    private static ThreadPool threadPool = new TestThreadPool(RestValidateQueryActionTests.class.getName());
+    private static NodeClient client = new NodeClient(Settings.EMPTY, threadPool);
+
+    private static UsageService usageService = new UsageService(Settings.EMPTY);
+    private static RestController controller = new RestController(Settings.EMPTY, emptySet(), null, client, null, usageService);
+    private static RestValidateQueryAction action = new RestValidateQueryAction(Settings.EMPTY, controller);
+
+    /**
+     * Configures {@link NodeClient} to stub {@link ValidateQueryAction} transport action.
+     * <p>
+     * This lower level of validation is out of the scope of this test.
+     */
+    @BeforeClass
+    public static void stubValidateQueryAction() {
+        final TaskManager taskManager = new TaskManager(Settings.EMPTY, threadPool, Collections.emptySet());
+
+        final TransportAction transportAction = new TransportAction(Settings.EMPTY, ValidateQueryAction.NAME,
+            new ActionFilters(Collections.emptySet()), taskManager) {
+            @Override
+            protected void doExecute(Task task, ActionRequest request, ActionListener listener) {
+            }
+        };
+
+        final Map<Action, TransportAction> actions = new HashMap<>();
+        actions.put(ValidateQueryAction.INSTANCE, transportAction);
+
+        client.initialize(actions, () -> "local", null);
+    }
+
+    @AfterClass
+    public static void terminateThreadPool() throws InterruptedException {
+        terminate(threadPool);
+
+        threadPool = null;
+        client = null;
+
+        usageService = null;
+        controller = null;
+        action = null;
+    }
+
+    public void testRestValidateQueryAction() throws Exception {
+        // GIVEN a valid query
+        final String content = "{\"query\":{\"bool\":{\"must\":{\"term\":{\"user\":\"kimchy\"}}}}}";
+
+        final RestRequest request = createRestRequest(content);
+        final FakeRestChannel channel = new FakeRestChannel(request, true, 0);
+
+        // WHEN
+        action.handleRequest(request, channel, client);
+
+        // THEN query is valid (i.e. not marked as invalid)
+        assertThat(channel.responses().get(), equalTo(0));
+        assertThat(channel.errors().get(), equalTo(0));
+        assertNull(channel.capturedResponse());
+    }
+
+    public void testRestValidateQueryAction_emptyQuery() throws Exception {
+        // GIVEN an empty (i.e. invalid) query wrapped into a valid JSON
+        final String content = "{\"query\":{}}";
+
+        final RestRequest request = createRestRequest(content);
+        final FakeRestChannel channel = new FakeRestChannel(request, true, 0);
+
+        // WHEN
+        action.handleRequest(request, channel, client);
+
+        // THEN query is marked as invalid
+        assertThat(channel.responses().get(), equalTo(1));
+        assertThat(channel.errors().get(), equalTo(0));
+        assertThat(channel.capturedResponse().content().utf8ToString(), containsString("{\"valid\":false}"));
+    }
+
+    public void testRestValidateQueryAction_malformedQuery() throws Exception {
+        // GIVEN an invalid query due to a malformed JSON
+        final String content = "{malformed_json}";
+
+        final RestRequest request = createRestRequest(content);
+        final FakeRestChannel channel = new FakeRestChannel(request, true, 0);
+
+        // WHEN
+        action.handleRequest(request, channel, client);
+
+        // THEN query is marked as invalid
+        assertThat(channel.responses().get(), equalTo(1));
+        assertThat(channel.errors().get(), equalTo(0));
+        assertThat(channel.capturedResponse().content().utf8ToString(), containsString("{\"valid\":false}"));
+    }
+
+    private RestRequest createRestRequest(String content) {
+        return new FakeRestRequest.Builder(xContentRegistry())
+            .withPath("index1/type1/_validate/query")
+            .withParams(emptyMap())
+            .withContent(new BytesArray(content), XContentType.JSON)
+            .build();
+    }
+}