checkstyle.xml

<!DOCTYPE module PUBLIC
  "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
  "https://checkstyle.org/dtds/configuration_1_3.dtd">

<module name="Checker">
  <property name="severity" value="warning"/>
  <property name="cacheFile" value="target/checkstyle-cache"/>
  <property name="fileExtensions" value="java"/>

  <module name="BeforeExecutionExclusionFileFilter">
    <property name="fileNamePattern" value=".*[\\/]src[\\/]main[\\/]java[\\/]io[\\/]github[\\/]arrayv[\\/]sorts.*$"/>
  </module>

  <module name="FileTabCharacter">
    <property name="eachLine" value="true"/>
  </module>

  <module name="NewlineAtEndOfFile"/>

  <module name="TreeWalker">
    <module name="SuppressionCommentFilter">
      <property name="offCommentFormat" value="@checkstyle\:off ([\w\|]+)"/>
      <property name="onCommentFormat" value="@checkstyle\:on ([\w\|]+)"/>
      <property name="checkFormat" value="$1"/>
    </module>

    <module name="Regexp">
      <property name="format" value="[ \t]+$"/>
      <property name="illegalPattern" value="true"/>
      <property name="message" value="Trailing whitespace"/>
    </module>

    <!-- Enforces that constants are in SHOUTING_SNAKE_CASE -->
    <module name="ConstantName"/>

    <!-- Handles the mistake described here: https://checkstyle.sourceforge.io/config_coding.html#CovariantEquals_Description -->
    <module name="CovariantEquals"/>

    <module name="FinalClass"/>

    <module name="GenericWhitespace"/>

    <module name="HideUtilityClassConstructor"/>

    <module name="Indentation">
      <property name="basicOffset" value="4"/>
    </module>

    <module name="InvalidJavadocPosition"/>

    <module name="JavadocMissingLeadingAsterisk"/>

    <module name="JavadocMissingWhitespaceAfterAsterisk"/>

    <module name="LeftCurly">
      <property name="option" value="eol"/>
      <property name="ignoreEnums" value="false"/>
    </module>

    <module name="LocalVariableName">
      <property name="format" value="^(Writes|Reads|Highlights|Delays|Sounds|Timer|[a-z][a-zA-Z0-9]*)$"/>
    </module>

    <module name="MemberName">
      <property name="format" value="^(Writes|Reads|Highlights|Delays|Sounds|Timer|[a-z][a-zA-Z0-9]*)$"/>
    </module>

    <module name="MethodName"/>

    <module name="MethodParamPad"/>

    <module name="ModifierOrder"/>

    <module name="MutableException"/>

    <module name="NoArrayTrailingComma"/>

    <module name="NoWhitespaceBefore"/>

    <module name="NoWhitespaceBeforeCaseDefaultColon"/>

    <module name="OuterTypeFilename"/>

    <module name="OuterTypeNumber"/>

    <module name="PackageName">
      <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
    </module>

    <module name="ParameterName">
      <property name="format" value="^(Writes|Reads|Highlights|Delays|Sounds|Timer|[a-z][a-zA-Z0-9]*)$"/>
    </module>

    <module name="ParenPad"/>

    <module name="RedundantImport"/>

    <module name="RedundantModifier"/>

    <module name="RightCurly">
      <property name="option" value="same"/>
    </module>

    <module name="SimplifyBooleanExpression"/>

    <module name="SimplifyBooleanReturn"/>

    <module name="StaticVariableName"/>

    <module name="SuperClone"/>

    <module name="SuperFinalize"/>

    <module name="TypecastParenPad"/>

    <module name="TypeName"/>

    <module name="UnnecessarySemicolonInEnumeration"/>

    <module name="UnnecessarySemicolonAfterOuterTypeDeclaration"/>

    <module name="UnnecessarySemicolonAfterTypeMemberDeclaration"/>

    <module name="UnusedImports"/>

    <module name="UpperEll"/>

    <module name="VisibilityModifier">
      <property name="packageAllowed" value="true"/>
      <property name="protectedAllowed" value="true"/>
    </module>

    <module name="WhitespaceAfter">
      <property name="tokens" value="COMMA, SEMI, LITERAL_IF, LITERAL_ELSE, LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, DO_WHILE" />
    </module>
  </module>
</module>