paper-mc/paper-checkstyle/.checkstyle/checkstyle.xml

<!DOCTYPE module PUBLIC
    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
    "https://checkstyle.org/dtds/configuration_1_3.dtd">
<module name="Checker">
    <module name="SuppressionFilter">
        <property name="file" value="${config_loc}/suppressions.xml"/>
        <property name="optional" value="false"/>
    </module>

    <!--Single Suppression Filters-->
    <module name="SuppressionSingleFilter">
        <!--Suppresses warnings except for common TYPE_USE that should be on same line-->
        <property name="checks" value="AnnotationOnSameLine"/>
        <property name="message" value="^Annotation '(?!(${type_use_annotations}))"/>
    </module>

    <!--Javadoc Comments-->
    <module name="JavadocPackage"/>
    <!--Misc-->
    <module name="NewlineAtEndOfFile"/>
    <module name="OrderedProperties"/>
    <!--Whitespace-->
    <module name="FileTabCharacter"/>

    <module name="TreeWalker">
        <module name="SuppressionXpathFilter">
            <property name="file" value="${config_loc}/xpath-suppressions.xml"/>
            <property name="optional" value="false"/>
        </module>

        <!--Annotations-->
        <module name="AnnotationOnSameLine">
            <!--matches all annotations, but most are suppressed in above-->
            <property name="tokens" value="METHOD_DEF"/>
        </module>
        <module name="AnnotationUseStyle"/>
        <module name="MissingDeprecated"/>

        <!--Block Checks-->
        <module name="AvoidNestedBlocks"/>
        <module name="EmptyBlock"/>
        <module name="LeftCurly"/>
        <module name="RightCurly"/>
        <module name="OneTopLevelClass"/>
        <module name="SealedShouldHavePermitsList"/>

        <!--Class Design-->
        <module name="FinalClass"/>
        <module name="HideUtilityClassConstructor"/>
        <module name="InterfaceIsType"/>

        <!--Coding-->
        <module name="ArrayTrailingComma"/>
        <module name="AvoidDoubleBraceInitialization"/>
        <module name="AvoidNoArgumentSuperConstructorCall"/>
        <module name="ConstructorsDeclarationGrouping"/>
        <module name="CovariantEquals"/>
        <module name="DeclarationOrder"/>
        <module name="DefaultComesLast"/>
        <module name="EmptyStatement"/>
        <module name="EqualsAvoidNull"/>
        <module name="EqualsHashCode"/>
        <module name="FallThrough"/>
        <module name="FinalLocalVariable">
            <property name="validateEnhancedForLoopVariable" value="true"/>
            <property name="validateUnnamedVariables" value="true"/>
            <property name="tokens" value="PARAMETER_DEF,VARIABLE_DEF"/>
        </module>
        <module name="IllegalToken"/> <!--just labels by default-->
        <module name="IllegalType"/>
        <module name="PatternVariableAssignment"/>
        <module name="RequireThis">
            <property name="validateOnlyOverlapping" value="false"/>
        </module>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <module name="StringLiteralEquality"/>
        <module name="UnnecessaryNullCheckWithInstanceOf"/>
        <module name="UnnecessarySemicolonAfterOuterTypeDeclaration"/>
        <module name="UnnecessarySemicolonAfterTypeMemberDeclaration"/>
        <module name="UnnecessarySemicolonInEnumeration"/>
        <module name="UnnecessarySemicolonInTryWithResources"/>
        <module name="UnusedCatchParameterShouldBeUnnamed"/>
        <module name="UnusedLambdaParameterShouldBeUnnamed"/>
        <module name="UnusedLocalVariable"/>
        <module name="WhenShouldBeUsed"/>

        <!--Headers--> <!--N/A-->

        <!--Imports-->
        <module name="AvoidStarImport"/>
        <module name="CustomImportOrder">
            <property name="customImportOrderRules" value="THIRD_PARTY_PACKAGE,STATIC"/>
            <property name="standardPackageRegExp" value="^$"/>
            <property name="sortImportsInGroupAlphabetically" value="true"/>
        </module>
        <module name="IllegalImport">
            <property name="regexp" value="true"/>
            <!--checker-qual nullability-->
            <property name="illegalClasses" value="org\.checkerframework\.checker\.nullness\.qual\.(Nullable|NonNull|DefaultQualifier)"/>
            <!--jetbrains nullability-->
            <property name="illegalClasses" value="org\.jetbrains\.annotations\.(NotNull|Nullable|NotNullByDefault)"/>
            <!--javax nullability-->
        </module>
        <module name="IllegalImport">
            <property name="regexp" value="true"/>
            <!--attempts to guard against nested imports (by looking for capital letters in imports)-->
            <property name="illegalClasses" value="^[^\.A-Z]+(\.[^\.A-Z]+)+?(\.[A-Z][^\.]*)(\.[A-Z][^\.]*)+$"/>
            <message key="import.illegal" value="Illegal nested import - {0}"/>
        </module>
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>

        <!--Javadoc Comments-->
        <module name="AtclauseOrder">
            <property name="tagOrder" value="@param, @return, @throws, @see, @deprecated, @hidden"/>
        </module>
        <module name="InvalidJavadocPosition"/>
        <module name="JavadocBlockTagLocation"/>
        <module name="JavadocContentLocation"/>
        <module name="JavadocLeadingAsteriskAlign"/>
        <module name="JavadocMethod">
            <!--checks all, but doesn't require. If we have a doc, it should be valid-->
            <property name="validateThrows" value="true"/>
        </module>
        <module name="JavadocMissingLeadingAsterisk"/>
        <module name="JavadocMissingWhitespaceAfterAsterisk"/>
        <module name="JavadocStyle"/> <!--checks all, but doesn't require. If we have a doc, it should be valid-->
        <module name="JavadocTagContinuationIndentation"/>
        <module name="JavadocType"/> <!--checks all, but doesn't require. If we have a doc, it should be valid-->
        <module name="NonEmptyAtclauseDescription"/>
        <module name="RequireEmptyLineBeforeBlockTagGroup"/>

        <!--Metrics--> <!--N/A-->

        <!--Miscellaneous-->
        <module name="ArrayTypeStyle"/>
        <module name="AvoidEscapedUnicodeCharacters"/>
        <module name="CommentsIndentation"/>
        <module name="FinalParameters">
            <!-- TODO pattern variable assignment isn't checked yet: PATTERN_VARIABLE_DEF-->
            <!-- https://github.com/checkstyle/checkstyle/issues/17366 -->
            <property name="tokens" value="METHOD_DEF,CTOR_DEF,LITERAL_CATCH,FOR_EACH_CLAUSE"/>
        </module>

        <module name="NoCodeInFile"/>
        <module name="OuterTypeFilename"/>
        <module name="UpperEll"/>

        <!--Modifiers-->
        <module name="ModifierOrder"/>
        <module name="RedundantModifier"/>

        <!--Naming Conventions-->
        <module name="AbbreviationAsWordInName">
            <property name="allowedAbbreviations" value="JSON,UUID"/>
            <property name="ignoreFinal" value="false"/>
        </module>
        <module name="ClassTypeParameterName"/>
        <module name="ConstantName"/>
        <module name="IllegalIdentifierName"/>
        <module name="InterfaceTypeParameterName"/>
        <module name="LambdaParameterName"/>
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="MethodName"/>
        <module name="MethodTypeParameterName"/>
        <module name="PackageName">
            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
        </module>
        <module name="ParameterName"/>
        <module name="PatternVariableName"/>
        <module name="RecordComponentName"/>
        <module name="RecordTypeParameterName"/>
        <module name="StaticVariableName"/>
        <module name="TypeName"/>

        <!--Regexp--> <!--N/A-->
        <!--Size Violations--> <!--N/A-->

        <!--Whitespace-->
        <module name="EmptyForInitializerPad"/>
        <module name="EmptyForIteratorPad"/>
        <module name="EmptyLineSeparator">
            <property name="allowNoEmptyLineBetweenFields" value="true"/>
            <property name="tokens" value="IMPORT,STATIC_IMPORT,CLASS_DEF,INTERFACE_DEF,ENUM_DEF,STATIC_INIT,INSTANCE_INIT,METHOD_DEF,CTOR_DEF,VARIABLE_DEF,RECORD_DEF,COMPACT_CTOR_DEF"/>
        </module>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="NoLineWrap"/> <!--just imports and packages-->
        <module name="NoWhitespaceAfter"/>
        <module name="NoWhitespaceBefore"/>
        <module name="NoWhitespaceBeforeCaseDefaultColon"/>
        <module name="ParenPad"/>
        <module name="SingleSpaceSeparator"/>
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround"/>

        <!--Custom-->
        <module name="JavadocAlignParameterDescription"/>
        <module name="NullabilityAnnotations"/>
        <module name="RedundantNullability"/>
    </module>
</module>