Bug Fixes for minor issues with SQL PIT refactor

legacy/src/main/java/org/opensearch/sql/legacy/executor/format/PrettyFormatRestExecutor.java

@@ -8,6 +8,7 @@
 import static org.opensearch.sql.common.setting.Settings.Key.SQL_PAGINATION_API_SEARCH_AFTER;
 
 import java.util.Map;
+import java.util.Objects;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.opensearch.OpenSearchException;
@@ -132,13 +133,11 @@ private Protocol buildProtocolForDefaultQuery(Client client, DefaultQueryAction
     return protocol;
   }
 
-  private boolean isDefaultCursor(SearchResponse searchResponse, DefaultQueryAction queryAction) {
+  protected boolean isDefaultCursor(SearchResponse searchResponse, DefaultQueryAction queryAction) {
     if (LocalClusterState.state().getSettingValue(SQL_PAGINATION_API_SEARCH_AFTER)) {
-      if (searchResponse.getHits().getTotalHits().value < queryAction.getSqlRequest().fetchSize()) {
-        return false;
-      } else {
-        return true;
-      }
+      return queryAction.getSqlRequest().fetchSize() != 0
+          && Objects.requireNonNull(searchResponse.getHits().getTotalHits()).value
+              >= queryAction.getSqlRequest().fetchSize();
     } else {
       return !Strings.isNullOrEmpty(searchResponse.getScrollId());
     }

legacy/src/main/java/org/opensearch/sql/legacy/executor/join/ElasticJoinExecutor.java

@@ -99,6 +99,7 @@ public void run() throws IOException, SqlParseException {
       this.metaResults.setTookImMilli(joinTimeInMilli);
     } catch (Exception e) {
       LOG.error("Failed during join query run.", e);
+      throw new IllegalStateException("Error occurred during join query run", e);
     } finally {
       if (LocalClusterState.state().getSettingValue(SQL_PAGINATION_API_SEARCH_AFTER)) {
         try {

legacy/src/test/java/org/opensearch/sql/legacy/executor/format/PrettyFormatRestExecutorTest.java

@@ -0,0 +1,89 @@
+package org.opensearch.sql.legacy.executor.format;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.opensearch.sql.common.setting.Settings.Key.SQL_PAGINATION_API_SEARCH_AFTER;
+
+import org.apache.lucene.search.TotalHits;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.search.SearchHit;
+import org.opensearch.search.SearchHits;
+import org.opensearch.sql.legacy.esdomain.LocalClusterState;
+import org.opensearch.sql.legacy.query.DefaultQueryAction;
+import org.opensearch.sql.legacy.request.SqlRequest;
+import org.opensearch.sql.opensearch.setting.OpenSearchSettings;
+
+@RunWith(MockitoJUnitRunner.class)
+public class PrettyFormatRestExecutorTest {
+
+  @Mock private SearchResponse searchResponse;
+  @Mock private SearchHits searchHits;
+  @Mock private SearchHit searchHit;
+  @Mock private DefaultQueryAction queryAction;
+  @Mock private SqlRequest sqlRequest;
+  private PrettyFormatRestExecutor executor;
+
+  @Before
+  public void setUp() {
+    OpenSearchSettings settings = mock(OpenSearchSettings.class);
+    LocalClusterState.state().setPluginSettings(settings);
+    when(LocalClusterState.state().getSettingValue(SQL_PAGINATION_API_SEARCH_AFTER))
+        .thenReturn(true);
+    when(queryAction.getSqlRequest()).thenReturn(sqlRequest);
+    executor = new PrettyFormatRestExecutor("jdbc");
+  }
+
+  @Test
+  public void testIsDefaultCursor_fetchSizeZero() {
+    when(sqlRequest.fetchSize()).thenReturn(0);
+
+    assertFalse(executor.isDefaultCursor(searchResponse, queryAction));
+  }
+
+  @Test
+  public void testIsDefaultCursor_totalHitsLessThanFetchSize() {
+    when(sqlRequest.fetchSize()).thenReturn(10);
+    when(searchResponse.getHits())
+        .thenReturn(
+            new SearchHits(
+                new SearchHit[] {searchHit}, new TotalHits(5, TotalHits.Relation.EQUAL_TO), 1.0F));
+
+    assertFalse(executor.isDefaultCursor(searchResponse, queryAction));
+  }
+
+  @Test
+  public void testIsDefaultCursor_totalHitsGreaterThanOrEqualToFetchSize() {
+    when(sqlRequest.fetchSize()).thenReturn(5);
+    when(searchResponse.getHits())
+        .thenReturn(
+            new SearchHits(
+                new SearchHit[] {searchHit}, new TotalHits(5, TotalHits.Relation.EQUAL_TO), 1.0F));
+
+    assertTrue(executor.isDefaultCursor(searchResponse, queryAction));
+  }
+
+  @Test
+  public void testIsDefaultCursor_PaginationApiDisabled() {
+    when(LocalClusterState.state().getSettingValue(SQL_PAGINATION_API_SEARCH_AFTER))
+        .thenReturn(false);
+    when(searchResponse.getScrollId()).thenReturn("someScrollId");
+
+    assertTrue(executor.isDefaultCursor(searchResponse, queryAction));
+  }
+
+  @Test
+  public void testIsDefaultCursor_PaginationApiDisabled_NoScrollId() {
+    when(LocalClusterState.state().getSettingValue(SQL_PAGINATION_API_SEARCH_AFTER))
+        .thenReturn(false);
+    when(searchResponse.getScrollId()).thenReturn(null);
+
+    assertFalse(executor.isDefaultCursor(searchResponse, queryAction));
+  }
+}