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.imports;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  import static com.puppycrawl.tools.checkstyle.checks.imports.UnusedImportsCheck.MSG_KEY;
  
  import java.io.File;
  import java.util.Arrays;
  import java.util.List;
  
  import org.junit.jupiter.api.Test;
  
  import com.google.common.collect.ImmutableMap;
  import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
  import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  public class UnusedImportsCheckTest extends AbstractModuleTestSupport {
  
      @Override
      protected String getPackageLocation() {
          return "com/puppycrawl/tools/checkstyle/checks/imports/unusedimports";
      }
  
      @Test
      public void testReferencedStateIsCleared() throws Exception {
          final DefaultConfiguration checkConfig = createModuleConfig(UnusedImportsCheck.class);
          final String inputWithoutWarnings = getPath("InputUnusedImportsWithoutWarnings.java");
          final String inputWithWarnings = getPath("InputUnusedImportsCheckClearState.java");
          final List<String> expectedFirstInput = Arrays.asList(CommonUtil.EMPTY_STRING_ARRAY);
          final List<String> expectedSecondInput = Arrays.asList(
                  "10:8: " + getCheckMessage(MSG_KEY, "java.util.Arrays"),
                  "11:8: " + getCheckMessage(MSG_KEY, "java.util.List"),
                  "12:8: " + getCheckMessage(MSG_KEY, "java.util.Set")
          );
          final File[] inputsWithWarningsFirst =
              {new File(inputWithWarnings), new File(inputWithoutWarnings)};
          final File[] inputsWithoutWarningFirst =
              {new File(inputWithoutWarnings), new File(inputWithWarnings)};
  
          verify(createChecker(checkConfig), inputsWithWarningsFirst, ImmutableMap.of(
                  inputWithoutWarnings, expectedFirstInput,
                  inputWithWarnings, expectedSecondInput));
          verify(createChecker(checkConfig), inputsWithoutWarningFirst, ImmutableMap.of(
                  inputWithoutWarnings, expectedFirstInput,
                  inputWithWarnings, expectedSecondInput));
      }
  
      @Test
      public void testWithoutProcessJavadoc() throws Exception {
          final String[] expected = {
              "11:8: " + getCheckMessage(MSG_KEY,
                  "com.puppycrawl.tools.checkstyle.checks."
                  + "imports.unusedimports.InputUnusedImportsBug"),
              "15:8: " + getCheckMessage(MSG_KEY, "java.lang.String"),
              "17:8: " + getCheckMessage(MSG_KEY, "java.util.List"),
              "18:8: " + getCheckMessage(MSG_KEY, "java.util.List"),
              "21:8: " + getCheckMessage(MSG_KEY, "java.util.Enumeration"),
              "24:8: " + getCheckMessage(MSG_KEY, "javax.swing.JToggleButton"),
              "26:8: " + getCheckMessage(MSG_KEY, "javax.swing.BorderFactory"),
              "31:15: " + getCheckMessage(MSG_KEY, "java.io.File.createTempFile"),
              // "33:8: Unused import - java.awt.Component.", // Should be detected
              "34:8: " + getCheckMessage(MSG_KEY, "java.awt.Graphics2D"),
              "35:8: " + getCheckMessage(MSG_KEY, "java.awt.HeadlessException"),
              "36:8: " + getCheckMessage(MSG_KEY, "java.awt.Label"),
              "37:8: " + getCheckMessage(MSG_KEY, "java.util.Date"),
              "38:8: " + getCheckMessage(MSG_KEY, "java.util.Calendar"),
              "39:8: " + getCheckMessage(MSG_KEY, "java.util.BitSet"),
              "41:8: " + getCheckMessage(MSG_KEY, "com.puppycrawl.tools.checkstyle.Checker"),
              "42:8: " + getCheckMessage(MSG_KEY, "com.puppycrawl.tools.checkstyle.CheckerTest"),
              "43:8: " + getCheckMessage(MSG_KEY, "com.puppycrawl.tools.checkstyle.Definitions"),
              "44:8: " + getCheckMessage(MSG_KEY,
                  "com.puppycrawl.tools.checkstyle.checks.imports.unusedimports."
                          + "InputUnusedImports15Extensions"),
              "45:8: " + getCheckMessage(MSG_KEY,
                  "com.puppycrawl.tools.checkstyle.ConfigurationLoaderTest"),
              "46:8: " + getCheckMessage(MSG_KEY,
                  "com.puppycrawl.tools.checkstyle.PackageNamesLoader"),
              "47:8: " + getCheckMessage(MSG_KEY,
                  "com.puppycrawl.tools.checkstyle.DefaultConfiguration"),
              "48:8: " + getCheckMessage(MSG_KEY, "com.puppycrawl.tools.checkstyle.DefaultLogger"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImports2.java"), expected);
      }
  
      @Test
      public void testProcessJavadoc() throws Exception {
          final String[] expected = {
              "11:8: " + getCheckMessage(MSG_KEY,
                      "com.puppycrawl.tools.checkstyle.checks."
                      + "imports.unusedimports.InputUnusedImportsBug"),
              "15:8: " + getCheckMessage(MSG_KEY, "java.lang.String"),
              "17:8: " + getCheckMessage(MSG_KEY, "java.util.List"),
              "18:8: " + getCheckMessage(MSG_KEY, "java.util.List"),
              "21:8: " + getCheckMessage(MSG_KEY, "java.util.Enumeration"),
              "24:8: " + getCheckMessage(MSG_KEY, "javax.swing.JToggleButton"),
              "26:8: " + getCheckMessage(MSG_KEY, "javax.swing.BorderFactory"),
              "31:15: " + getCheckMessage(MSG_KEY, "java.io.File.createTempFile"),
              // "30:8: Unused import - java.awt.Component.", // Should be detected
              "36:8: " + getCheckMessage(MSG_KEY, "java.awt.Label"),
              "48:8: " + getCheckMessage(MSG_KEY, "com.puppycrawl.tools.checkstyle.DefaultLogger"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImports.java"), expected);
      }
  
      @Test
      public void testProcessJavadocWithLinkTag() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsWithValueTag.java"), expected);
      }
  
      @Test
      public void testProcessJavadocWithBlockTagContainingMethodParameters() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsWithBlockMethodParameters.java"), expected);
      }
  
      @Test
      public void testAnnotations() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputUnusedImportsAnnotations.java"), expected);
      }
  
      @Test
      public void testArrayRef() throws Exception {
          final String[] expected = {
              "13:8: " + getCheckMessage(MSG_KEY, "java.util.ArrayList"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsArrayRef.java"), expected);
      }
  
      @Test
      public void testBug() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsBug.java"), expected);
      }
  
      @Test
      public void testNewlinesInsideTags() throws Exception {
          final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsWithNewlinesInsideTags.java"), expected);
      }
  
      @Test
      public void testGetRequiredTokens() {
          final UnusedImportsCheck testCheckObject =
                  new UnusedImportsCheck();
          final int[] actual = testCheckObject.getRequiredTokens();
          final int[] expected = {
              TokenTypes.IDENT,
              TokenTypes.IMPORT,
              TokenTypes.STATIC_IMPORT,
              // Definitions that may contain Javadoc...
              TokenTypes.PACKAGE_DEF,
              TokenTypes.ANNOTATION_DEF,
              TokenTypes.ANNOTATION_FIELD_DEF,
              TokenTypes.ENUM_DEF,
              TokenTypes.ENUM_CONSTANT_DEF,
              TokenTypes.CLASS_DEF,
              TokenTypes.INTERFACE_DEF,
              TokenTypes.METHOD_DEF,
              TokenTypes.CTOR_DEF,
              TokenTypes.VARIABLE_DEF,
              TokenTypes.RECORD_DEF,
              TokenTypes.COMPACT_CTOR_DEF,
              TokenTypes.OBJBLOCK,
              TokenTypes.SLIST,
          };
  
          assertWithMessage("Default required tokens are invalid")
              .that(actual)
              .isEqualTo(expected);
      }
  
      @Test
      public void testGetAcceptableTokens() {
          final UnusedImportsCheck testCheckObject =
                  new UnusedImportsCheck();
          final int[] actual = testCheckObject.getAcceptableTokens();
          final int[] expected = {
              TokenTypes.IDENT,
              TokenTypes.IMPORT,
              TokenTypes.STATIC_IMPORT,
              // Definitions that may contain Javadoc...
              TokenTypes.PACKAGE_DEF,
              TokenTypes.ANNOTATION_DEF,
              TokenTypes.ANNOTATION_FIELD_DEF,
              TokenTypes.ENUM_DEF,
              TokenTypes.ENUM_CONSTANT_DEF,
              TokenTypes.CLASS_DEF,
              TokenTypes.INTERFACE_DEF,
              TokenTypes.METHOD_DEF,
              TokenTypes.CTOR_DEF,
              TokenTypes.VARIABLE_DEF,
              TokenTypes.RECORD_DEF,
              TokenTypes.COMPACT_CTOR_DEF,
              TokenTypes.OBJBLOCK,
              TokenTypes.SLIST,
          };
  
          assertWithMessage("Default acceptable tokens are invalid")
              .that(actual)
              .isEqualTo(expected);
      }
  
      @Test
      public void testFileInUnnamedPackage() throws Exception {
          final String[] expected = {
              "12:8: " + getCheckMessage(MSG_KEY, "java.util.Arrays"),
              "13:8: " + getCheckMessage(MSG_KEY, "java.lang.String"),
          };
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputUnusedImportsFileInUnnamedPackage.java"),
              expected);
      }
  
      @Test
      public void testImportsFromJavaLang() throws Exception {
          final String[] expected = {
              "10:8: " + getCheckMessage(MSG_KEY, "java.lang.String"),
              "11:8: " + getCheckMessage(MSG_KEY, "java.lang.Math"),
              "12:8: " + getCheckMessage(MSG_KEY, "java.lang.Class"),
              "13:8: " + getCheckMessage(MSG_KEY, "java.lang.Exception"),
              "14:8: " + getCheckMessage(MSG_KEY, "java.lang.Runnable"),
              "15:8: " + getCheckMessage(MSG_KEY, "java.lang.RuntimeException"),
              "16:8: " + getCheckMessage(MSG_KEY, "java.lang.ProcessBuilder"),
              "17:8: " + getCheckMessage(MSG_KEY, "java.lang.Double"),
              "18:8: " + getCheckMessage(MSG_KEY, "java.lang.Integer"),
              "19:8: " + getCheckMessage(MSG_KEY, "java.lang.Float"),
              "20:8: " + getCheckMessage(MSG_KEY, "java.lang.Short"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsFromJavaLang.java"), expected);
      }
  
      @Test
      public void testImportsJavadocQualifiedName() throws Exception {
          final String[] expected = {
              "11:8: " + getCheckMessage(MSG_KEY, "java.util.List"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsJavadocQualifiedName.java"), expected);
      }
  
      @Test
      public void testSingleWordPackage() throws Exception {
          final String[] expected = {
              "10:8: " + getCheckMessage(MSG_KEY, "module"),
          };
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputUnusedImportsSingleWordPackage.java"),
                  expected);
      }
  
      @Test
      public void testRecordsAndCompactCtors() throws Exception {
          final String[] expected = {
              "19:8: " + getCheckMessage(MSG_KEY, "javax.swing.JToolBar"),
              "20:8: " + getCheckMessage(MSG_KEY, "javax.swing.JToggleButton"),
          };
          verifyWithInlineConfigParser(
                  getNonCompilablePath("InputUnusedImportsRecordsAndCompactCtors.java"),
                  expected);
      }
  
      @Test
      public void testShadowedImports() throws Exception {
          final String[] expected = {
              "12:8: " + getCheckMessage(MSG_KEY, "java.util.Map"),
              "13:8: " + getCheckMessage(MSG_KEY, "java.util.Set"),
              "16:8: " + getCheckMessage(MSG_KEY, "com.puppycrawl.tools.checkstyle.checks.imports."
                      + "unusedimports.InputUnusedImportsShadowed"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImportsShadowed.java"), expected);
      }
  
      @Test
      public void testUnusedImports3() throws Exception {
          final String[] expected = {
              "11:8: " + getCheckMessage(MSG_KEY, "java.awt.Rectangle"),
              "13:8: " + getCheckMessage(MSG_KEY, "java.awt.event.KeyEvent"),
          };
          verifyWithInlineConfigParser(
                  getPath("InputUnusedImports3.java"), expected);
      }
  
      @Test
      public void testStateIsClearedOnBeginTreeCollect() throws Exception {
          final DefaultConfiguration checkConfig = createModuleConfig(UnusedImportsCheck.class);
          final String file1 = getNonCompilablePath(
                  "InputUnusedImportsRecordsAndCompactCtors.java");
          final String file2 = getNonCompilablePath(
                  "InputUnusedImportsSingleWordPackage.java");
          final List<String> expectedFirstInput = List.of(
              "19:8: " + getCheckMessage(MSG_KEY, "javax.swing.JToolBar"),
              "20:8: " + getCheckMessage(MSG_KEY, "javax.swing.JToggleButton")
          );
          final List<String> expectedSecondInput = List.of(
              "10:8: " + getCheckMessage(MSG_KEY, "module")
          );
          final File[] inputs = {new File(file1), new File(file2)};
  
          verify(createChecker(checkConfig), inputs, ImmutableMap.of(
              file1, expectedFirstInput,
              file2, expectedSecondInput));
      }
  }
  