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.filters;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  
  import org.junit.jupiter.api.Test;
  
  import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
  import com.puppycrawl.tools.checkstyle.api.AuditEvent;
  import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
  import com.puppycrawl.tools.checkstyle.api.SeverityLevel;
  import com.puppycrawl.tools.checkstyle.api.Violation;
  
  public class SeverityMatchFilterTest {
  
      private final SeverityMatchFilter filter = new SeverityMatchFilter();
  
      @Test
      public void testDefault() {
          final AuditEvent ev = new AuditEvent(this, "Test.java");
          assertWithMessage("no message")
              .that(filter.accept(ev))
              .isFalse();
          final SeverityLevel errorLevel = SeverityLevel.ERROR;
          final Violation errorMessage =
              new Violation(1, 0, "", "", null,
                  errorLevel, null, getClass(), null);
          final AuditEvent ev2 = new AuditEvent(this, "ATest.java", errorMessage);
          assertWithMessage("level:" + errorLevel)
                  .that(filter.accept(ev2))
                  .isTrue();
          final SeverityLevel infoLevel = SeverityLevel.INFO;
          final Violation infoViolation =
                  new Violation(1, 0, "", "", null, infoLevel, null, getClass(), null);
          final AuditEvent ev3 = new AuditEvent(this, "ATest.java", infoViolation);
          assertWithMessage("level:" + infoLevel)
              .that(filter.accept(ev3))
              .isFalse();
      }
  
      @Test
      public void testSeverity() {
          filter.setSeverity(SeverityLevel.INFO);
          final AuditEvent ev = new AuditEvent(this, "Test.java");
          // event with no message has severity level INFO
          assertWithMessage("no message")
                  .that(filter.accept(ev))
                  .isTrue();
          final SeverityLevel errorLevel = SeverityLevel.ERROR;
          final Violation errorMessage =
              new Violation(1, 0, "", "", null,
                  errorLevel, null, getClass(), null);
          final AuditEvent ev2 = new AuditEvent(this, "ATest.java", errorMessage);
          assertWithMessage("level:" + errorLevel)
              .that(filter.accept(ev2))
              .isFalse();
          final SeverityLevel infoLevel = SeverityLevel.INFO;
          final Violation infoMessage =
                  new Violation(1, 0, "", "", null, infoLevel, null, getClass(), null);
          final AuditEvent ev3 = new AuditEvent(this, "ATest.java", infoMessage);
          assertWithMessage("level:" + infoLevel)
                  .that(filter.accept(ev3))
                  .isTrue();
      }
  
      @Test
      public void testAcceptOnMatch() {
          filter.setSeverity(SeverityLevel.INFO);
          filter.setAcceptOnMatch(false);
          final AuditEvent ev = new AuditEvent(this, "Test.java");
          // event with no message has severity level INFO
          assertWithMessage("no message")
              .that(filter.accept(ev))
              .isFalse();
          final SeverityLevel errorLevel = SeverityLevel.ERROR;
          final Violation errorViolation =
              new Violation(1, 0, "", "", null,
                  errorLevel, null, getClass(), null);
          final AuditEvent ev2 = new AuditEvent(this, "ATest.java", errorViolation);
          assertWithMessage("level:" + errorLevel)
                  .that(filter.accept(ev2))
                  .isTrue();
          final SeverityLevel infoLevel = SeverityLevel.INFO;
          final Violation infoViolation = new Violation(1, 0, "", "", null, infoLevel,
              null, getClass(), null);
          final AuditEvent ev3 = new AuditEvent(this, "ATest.java", infoViolation);
          assertWithMessage("level:" + infoLevel)
              .that(filter.accept(ev3))
              .isFalse();
      }
  
      @Test
      public void testConfigure() throws CheckstyleException {
          filter.configure(new DefaultConfiguration("test"));
          assertWithMessage("object exists")
              .that(filter)
              .isNotNull();
      }
  
  }
  