foreign/java/dev-support/checkstyle/checkstyle.xml

<?xml version="1.0"?>
<!--
 Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements.  See the NOTICE file
 distributed with this work for additional information
 regarding copyright ownership.  The ASF licenses this file
 to you under the Apache License, Version 2.0 (the
 "License"); you may not use this file except in compliance
 with the License.  You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing,
 software distributed under the License is distributed on an
 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
-->
<!DOCTYPE module PUBLIC
    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
    "https://checkstyle.org/dtds/configuration_1_3.dtd">

<!--
  Checkstyle configuration for Apache Iggy.

  This configuration focuses on semantic code quality checks.
  Formatting checks are handled by Spotless (Palantir Java Format).
-->

<module name="Checker">
    <property name="fileExtensions" value="java, properties, xml"/>

    <module name="SuppressWarningsFilter"/>

    <!-- Suppressions file for skipping specific checks -->
    <module name="SuppressionFilter">
        <property name="file" value="${config_loc}/suppressions.xml"/>
        <property name="optional" value="false"/>
    </module>

    <!-- Checks that property files contain the same keys. -->
    <module name="Translation"/>

    <!-- Checks for Size Violations. -->
    <module name="FileLength"/>

    <!-- Enforce logger variable name to be 'log' -->
    <module name="RegexpSingleline">
        <property name="format" value="private\s+(static\s+)?(final\s+)?Logger\s+(?!log\s*[;=])"/>
        <property name="message" value="Logger variable must be named 'log'"/>
    </module>

    <module name="TreeWalker">
        <module name="SuppressWarningsHolder"/>
        <module name="SuppressionCommentFilter"/>
        <module name="SuppressWithNearbyCommentFilter"/>

        <!-- Checks for Javadoc comments. -->
        <!--
        <module name="JavadocMethod">
            <property name="accessModifiers" value="public"/>
        </module>
        <module name="JavadocType">
            <property name="scope" value="public"/>
        </module>
        <module name="JavadocStyle"/>
        <module name="MissingJavadocType">
            <property name="scope" value="public"/>
        </module>
        <module name="MissingJavadocMethod">
            <property name="scope" value="public"/>
        </module>
        -->

        <!-- Checks for Naming Conventions. -->
        <module name="ConstantName">
            <property name="format" value="^log$|^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$"/>
        </module>
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName">
            <property name="format" value="^(_?[a-z][a-zA-Z0-9]*|_)$"/>
        </module>
        <module name="MemberName"/>
        <module name="MethodName"/>
        <module name="PackageName"/>
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>
        <module name="TypeName"/>

        <!-- Checks for imports -->
        <module name="IllegalImport"/>

        <!-- Checks for Size Violations. -->
        <module name="MethodLength"/>
        <module name="ParameterNumber">
            <property name="ignoreOverriddenMethods" value="true"/>
        </module>

        <!-- Complexity checks -->
        <module name="CyclomaticComplexity">
            <property name="max" value="10"/>
        </module>
        <module name="NPathComplexity">
            <property name="max" value="200"/>
        </module>

        <!-- Modifier Checks -->
        <module name="ModifierOrder"/>

        <!-- Checks for blocks. -->
        <module name="AvoidNestedBlocks"/>
        <module name="EmptyBlock"/>
        <module name="NeedBraces"/>

        <!-- Checks for common coding problems -->
        <module name="AvoidDoubleBraceInitialization"/>
        <module name="CovariantEquals"/>
        <module name="DefaultComesLast"/>
        <module name="EmptyStatement"/>
        <module name="EqualsAvoidNull"/>
        <module name="EqualsHashCode"/>
        <module name="FallThrough"/>
        <module name="HiddenField">
            <property name="ignoreConstructorParameter" value="true"/>
            <property name="ignoreSetter" value="true"/>
            <property name="setterCanReturnItsClass" value="true"/>
            <property name="tokens" value="VARIABLE_DEF"/>
        </module>
        <module name="IllegalCatch">
            <property name="illegalClassNames" value="Exception, Throwable"/>
        </module>
        <module name="IllegalInstantiation"/>
        <module name="IllegalThrows">
            <property name="illegalClassNames" value="Exception, Throwable"/>
        </module>
        <module name="MissingOverride"/>
        <module name="MissingSwitchDefault"/>
        <module name="MultipleVariableDeclarations"/>
        <module name="NoClone"/>
        <module name="NoFinalizer"/>
        <module name="OneStatementPerLine"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <module name="StringLiteralEquality"/>
        <module name="UnnecessarySemicolonInEnumeration"/>

        <!-- Checks for class design -->
        <module name="FinalClass"/>
        <module name="HideUtilityClassConstructor"/>
        <module name="InnerTypeLast"/>
        <module name="InterfaceIsType"/>
        <module name="VisibilityModifier"/>

        <!-- Code organization -->
        <module name="DeclarationOrder"/>
        <module name="OuterTypeFilename"/>
        <module name="OverloadMethodsDeclarationOrder"/>
        <module name="PackageDeclaration"/>

        <!-- Miscellaneous other checks. -->
        <module name="ArrayTypeStyle"/>
        <module name="UpperEll"/>

    </module>

</module>