code: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF 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.apache.skywalking.oap.server.core.storage.model;
  
  import org.junit.jupiter.api.Assertions;
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  public class SQLDatabaseExtensionTest {
      @Test
      public void testIndexColumns() {
          final SQLDatabaseExtension.MultiColumnsIndex extraQueryIndex = new SQLDatabaseExtension.MultiColumnsIndex(
                  "a1", new String[]{"a2"});
          Assertions.assertArrayEquals(new String[]{
                  "a1",
                  "a2"
          }, extraQueryIndex.getColumns());
      }
  
      @Test
      public void testIllegalIndexColumns() {
          assertThrows(IllegalArgumentException.class,
                  () -> new SQLDatabaseExtension.MultiColumnsIndex("a1", new String[0]));
      }
  }
  