content: /*
   * 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
   *
   *    https://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.bigtop.manager.common.utils;
  
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNull;
  
  public class CaseUtilsTest {
  
      @Test
      public void testToLowerCase() {
          // Normal case
          assertEquals("hello world", CaseUtils.toLowerCase("Hello World"));
          // Input is an empty string
          assertEquals("", CaseUtils.toLowerCase(""));
          // Input is null
          assertNull(CaseUtils.toLowerCase(null));
      }
  
      @Test
      public void testToUpperCase() {
          // Normal case
          assertEquals("HELLO WORLD", CaseUtils.toUpperCase("Hello World"));
          // Input is an empty string
          assertEquals("", CaseUtils.toUpperCase(""));
          // Input is null
          assertNull(CaseUtils.toUpperCase(null));
      }
  
      @Test
      public void testToCamelCase() {
          // Normal case
          assertEquals("HelloWorld", CaseUtils.toCamelCase("hello-world"));
          // Using underscore separator
          assertEquals("HelloWorld", CaseUtils.toCamelCase("hello_world", CaseUtils.SEPARATOR_UNDERSCORE));
          // First letter lowercase
          assertEquals("helloWorld", CaseUtils.toCamelCase("hello-world", CaseUtils.SEPARATOR_HYPHEN, false));
          // Input is an empty string
          assertEquals("", CaseUtils.toCamelCase(""));
          // Input is null
          assertNull(CaseUtils.toCamelCase(null));
      }
  
      @Test
      public void testToHyphenCase() {
          // Normal case
          assertEquals("hello-world", CaseUtils.toHyphenCase("HelloWorld"));
          // Input is an empty string
          assertEquals("", CaseUtils.toHyphenCase(""));
          // Input is null
          assertNull(CaseUtils.toHyphenCase(null));
      }
  
      @Test
      public void testToUnderScoreCase() {
          // Normal case
          assertEquals("hello_world", CaseUtils.toUnderScoreCase("HelloWorld"));
          // Input is an empty string
          assertEquals("", CaseUtils.toUnderScoreCase(""));
          // Input is null
          assertNull(CaseUtils.toUnderScoreCase(null));
      }
  }
  