fix tests

Signed-off-by: Kai Huang <ahkcs@amazon.com>

Author: ahkcs

core/src/test/java/org/opensearch/sql/executor/execution/QueryPlanTest.java

@@ -6,14 +6,12 @@
 package org.opensearch.sql.executor.execution;
 
 import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
-import org.apache.commons.lang3.NotImplementedException;
 import org.junit.jupiter.api.DisplayNameGeneration;
 import org.junit.jupiter.api.DisplayNameGenerator;
 import org.junit.jupiter.api.Test;
@@ -110,20 +108,14 @@ public void onFailure(Exception e) {
   }
 
   @Test
-  public void explain_is_not_supported_for_pagination() {
-    new QueryPlan(null, null, null, 0, null, null)
-        .explain(
-            new ResponseListener<>() {
-              @Override
-              public void onResponse(ExecutionEngine.ExplainResponse response) {
-                fail();
-              }
-
-              @Override
-              public void onFailure(Exception e) {
-                assertTrue(e instanceof NotImplementedException);
-              }
-            },
-            format);
+  public void explain_with_pagination() {
+    int pageSize = 10;
+    int offset = 5;
+    QueryPlan query =
+        new QueryPlan(queryId, queryType, plan, pageSize, offset, queryService, queryListener);
+    query.explain(explainListener, format);
+
+    verify(queryService, times(1))
+        .explain(plan, queryType, explainListener, format, pageSize, offset);
   }
 }

integ-test/src/test/java/org/opensearch/sql/sql/StandalonePaginationIT.java

@@ -140,22 +140,13 @@ public void onFailure(Exception e) {
 
   @Test
   @SneakyThrows
-  public void test_explain_not_supported() {
+  public void test_explain_cursor_not_supported() {
     var request = new Request("POST", "_plugins/_sql/_explain");
-    // Request should be rejected before index names are resolved
-    request.setJsonEntity("{ \"query\": \"select * from something\", \"fetch_size\": 10 }");
+    // Explain with cursor continuation should be rejected
+    request.setJsonEntity("{ \"cursor\" : \"n:0000\" }");
     var exception = assertThrows(ResponseException.class, () -> client().performRequest(request));
     var response =
         new JSONObject(new String(exception.getResponse().getEntity().getContent().readAllBytes()));
-    assertEquals(
-        "`explain` feature for paginated requests is not implemented yet.",
-        response.getJSONObject("error").getString("details"));
-
-    // Request should be rejected before cursor parsed
-    request.setJsonEntity("{ \"cursor\" : \"n:0000\" }");
-    exception = assertThrows(ResponseException.class, () -> client().performRequest(request));
-    response =
-        new JSONObject(new String(exception.getResponse().getEntity().getContent().readAllBytes()));
     assertEquals(
         "Explain of a paged query continuation is not supported. Use `explain` for the initial"
             + " query request.",