code: ///////////////////////////////////////////////////////////////////////////////////////////////
  // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
  // Copyright (C) 2001-2023 the original author or authors.
  //
  // This library is free software; you can redistribute it and/or
  // modify it under the terms of the GNU Lesser General Public
  // License as published by the Free Software Foundation; either
  // version 2.1 of the License, or (at your option) any later version.
  //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ///////////////////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.checks.naming;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  import static com.puppycrawl.tools.checkstyle.checks.naming.AbstractNameCheck.MSG_INVALID_PATTERN;
  
  import org.junit.jupiter.api.Test;
  
  import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
  import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
  import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  public class ConstantNameCheckTest
      extends AbstractModuleTestSupport {
  
      @Override
      protected String getPackageLocation() {
          return "com/puppycrawl/tools/checkstyle/checks/naming/constantname";
      }
  
      @Test
      public void testGetRequiredTokens() {
          final ConstantNameCheck checkObj = new ConstantNameCheck();
          final int[] expected = {TokenTypes.VARIABLE_DEF};
          assertWithMessage("Default required tokens are invalid")
              .that(checkObj.getRequiredTokens())
              .isEqualTo(expected);
      }
  
      @Test
      public void testIllegalRegexp()
              throws Exception {
          final DefaultConfiguration checkConfig =
              createModuleConfig(ConstantNameCheck.class);
          checkConfig.addProperty("format", "\\");
          try {
              createChecker(checkConfig);
              assertWithMessage("CheckstyleException is expected").fail();
          }
          catch (CheckstyleException ex) {
              assertWithMessage("Invalid exception message")
                  .that(ex.getMessage())
                  .isEqualTo("cannot initialize module com.puppycrawl.tools.checkstyle.TreeWalker - "
                      + "cannot initialize module com.puppycrawl.tools.checkstyle.checks."
                      + "naming.ConstantNameCheck - "
                      + "illegal value '\\' for property 'format'");
          }
      }
  
      @Test
      public void testDefault()
              throws Exception {
  
          final String pattern = "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$";
  
          final String[] expected = {
              "31:29: " + getCheckMessage(MSG_INVALID_PATTERN, "badConstant", pattern),
              "148:30: " + getCheckMessage(MSG_INVALID_PATTERN, "BAD__NAME", pattern),
          };
          verifyWithInlineConfigParser(
                  getPath("InputConstantNameSimple1.java"), expected);
      }
  
      @Test
      public void testAccessControlTuning()
              throws Exception {
  
          final String pattern = "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$";
  
          final String[] expected = {
              "148:30: " + getCheckMessage(MSG_INVALID_PATTERN, "BAD__NAME", pattern),
          };
          verifyWithInlineConfigParser(
                  getPath("InputConstantNameSimple2.java"), expected);
      }
  
      @Test
      public void testInterfaceAndAnnotation()
              throws Exception {
  
          final String pattern = "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$";
  
          final String[] expected = {
              "31:16: " + getCheckMessage(MSG_INVALID_PATTERN, "data", pattern),
              "71:16: " + getCheckMessage(MSG_INVALID_PATTERN, "data", pattern),
          };
          verifyWithInlineConfigParser(
                  getPath("InputConstantNameInner.java"), expected);
      }
  
      @Test
      public void testDefault1()
              throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputConstantName.java"), expected);
      }
  
      @Test
      public void testIntoInterface() throws Exception {
  
          final String pattern = "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$";
  
          final String[] expected = {
              "56:16: " + getCheckMessage(MSG_INVALID_PATTERN, "mPublic", pattern),
              "57:9: " + getCheckMessage(MSG_INVALID_PATTERN, "mProtected", pattern),
              "58:9: " + getCheckMessage(MSG_INVALID_PATTERN, "mPackage", pattern),
              "59:9: " + getCheckMessage(MSG_INVALID_PATTERN, "mPrivate", pattern),
              "61:16: " + getCheckMessage(MSG_INVALID_PATTERN, "_public", pattern),
              "62:9: " + getCheckMessage(MSG_INVALID_PATTERN, "_protected", pattern),
              "63:9: " + getCheckMessage(MSG_INVALID_PATTERN, "_package", pattern),
              "64:9: " + getCheckMessage(MSG_INVALID_PATTERN, "_private", pattern),
          };
          verifyWithInlineConfigParser(
                  getPath("InputConstantNameMemberExtended.java"), expected);
      }
  
      @Test
      public void testIntoInterfaceExcludePublic() throws Exception {
  
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputConstantNameInterfaceIgnorePublic.java"), expected);
      }
  
      @Test
      public void testStaticMethodInInterface()
              throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputConstantNameStaticModifierInInterface.java"), expected);
      }
  
      @Test
      public void testGetAcceptableTokens() {
          final ConstantNameCheck constantNameCheckObj = new ConstantNameCheck();
          final int[] actual = constantNameCheckObj.getAcceptableTokens();
          final int[] expected = {
              TokenTypes.VARIABLE_DEF,
          };
          assertWithMessage("Default acceptable should not be null")
              .that(actual)
              .isNotNull();
          assertWithMessage("Default acceptable tokens are invalid")
              .that(actual)
              .isEqualTo(expected);
      }
  
  }
  