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[\\/](?!templates[\\/]Sort.java$).*$" />
  </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>