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Signed-off-by: Tomoyuki Morita <moritato@amazon.com>

async-query-core/src/main/java/org/opensearch/sql/spark/validator/FunctionType.java

@@ -11,6 +11,10 @@
 import java.util.stream.Collectors;
 import lombok.AllArgsConstructor;
 
+/**
+ * Enum for defining and looking up SQL function type based on its name. Unknown one will be
+ * considered as UDF (User Defined Function)
+ */
 @AllArgsConstructor
 public enum FunctionType {
   AGGREGATE("Aggregate"),

async-query-core/src/main/java/org/opensearch/sql/spark/validator/GrammarElementValidator.java

@@ -5,6 +5,11 @@
 
 package org.opensearch.sql.spark.validator;
 
+/** Interface for validator to decide if each GrammarElement is valid or not. */
 public interface GrammarElementValidator {
+
+  /**
+   * @return true if element is valid (accepted)
+   */
   boolean isValid(GrammarElement element);
 }

async-query-core/src/main/java/org/opensearch/sql/spark/validator/GrammarElementValidatorProvider.java

@@ -9,6 +9,7 @@
 import lombok.AllArgsConstructor;
 import org.opensearch.sql.datasource.model.DataSourceType;
 
+/** Provides GrammarElementValidator based on DataSourceType. */
 @AllArgsConstructor
 public class GrammarElementValidatorProvider {
 

async-query-core/src/main/java/org/opensearch/sql/spark/validator/SQLQueryValidationVisitor.java

@@ -84,6 +84,7 @@
 import org.opensearch.sql.spark.antlr.parser.SqlBaseParser.UnsetNamespacePropertiesContext;
 import org.opensearch.sql.spark.antlr.parser.SqlBaseParserBaseVisitor;
 
+/** This visitor validate grammar using GrammarElementValidator */
 @AllArgsConstructor
 public class SQLQueryValidationVisitor extends SqlBaseParserBaseVisitor<Void> {
   private final GrammarElementValidator grammarElementValidator;

async-query-core/src/main/java/org/opensearch/sql/spark/validator/SQLQueryValidator.java

@@ -9,10 +9,18 @@
 import org.opensearch.sql.datasource.model.DataSourceType;
 import org.opensearch.sql.spark.utils.SQLQueryUtils;
 
+/** Validate input SQL query based on the DataSourceType. */
 @AllArgsConstructor
 public class SQLQueryValidator {
   private final GrammarElementValidatorProvider grammarElementValidatorProvider;
 
+  /**
+   * It will look up validator associated with the DataSourceType, and throw
+   * IllegalArgumentException if invalid grammar element is found.
+   *
+   * @param sqlQuery The query to be validated
+   * @param datasourceType
+   */
   public void validate(String sqlQuery, DataSourceType datasourceType) {
     GrammarElementValidator grammarElementValidator =
         grammarElementValidatorProvider.getValidatorForDatasource(datasourceType);

async-query-core/src/test/java/org/opensearch/sql/spark/validator/SQLQueryValidatorTest.java

@@ -211,16 +211,14 @@ private enum TestElement {
   void testAllowAllByDefault() {
     when(mockedProvider.getValidatorForDatasource(any()))
         .thenReturn(new DefaultGrammarElementValidator());
-    VerifyValidator v =
-        new VerifyValidator(sqlQueryValidator, DataSourceType.SPARK);
+    VerifyValidator v = new VerifyValidator(sqlQueryValidator, DataSourceType.SPARK);
     Arrays.stream(TestElement.values()).forEach(v::ok);
   }
 
   @Test
   void testDenyAllValidator() {
     when(mockedProvider.getValidatorForDatasource(any())).thenReturn(element -> false);
-    VerifyValidator v =
-        new VerifyValidator(sqlQueryValidator, DataSourceType.SPARK);
+    VerifyValidator v = new VerifyValidator(sqlQueryValidator, DataSourceType.SPARK);
     // The elements which doesn't have validation will be accepted.
     // That's why there are some ok case