peakup/peakup-backend/checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
        "https://checkstyle.org/dtds/configuration_1_3.dtd">

<!--
  Checkstyle configuration mirroring IntelliJ IDEA's default Java code style.
  - 4-space indentation, no tabs
  - 250-char line length
  - K&R brace style (opening brace on same line)
  - Standard naming conventions (lowerCamelCase, UpperCamelCase, UPPER_SNAKE)
  - Suppressions for mapper files (aligned @Mapping annotations) in suppressions.xml
-->
<module name="Checker">
    <property name="severity" value="error"/>
    <property name="fileExtensions" value="java"/>

    <!-- No tab characters anywhere in the file -->
    <module name="FileTabCharacter">
        <property name="eachLine" value="true"/>
    </module>

    <!-- Files must end with a newline -->
    <module name="NewlineAtEndOfFile"/>

    <!-- No trailing whitespace -->
    <module name="RegexpSingleline">
        <property name="format" value="\s+$"/>
        <property name="message" value="Trailing whitespace"/>
    </module>

    <!-- 240-char line length; imports and URLs ignored -->
    <module name="LineLength">
        <property name="max" value="240"/>
        <property name="ignorePattern" value="^package.*|^import.*|https?://|ftp://"/>
    </module>

    <module name="TreeWalker">

        <!-- ===== IMPORTS ===== -->
        <module name="AvoidStarImport"/>
        <module name="UnusedImports"/>

        <!-- ===== INDENTATION ===== -->
        <module name="Indentation">
            <property name="basicOffset" value="4"/>
            <property name="braceAdjustment" value="0"/>
            <property name="caseIndent" value="4"/>
            <property name="throwsIndent" value="8"/>
            <property name="lineWrappingIndentation" value="8"/>
            <property name="arrayInitIndent" value="4"/>
        </module>

        <!-- ===== BRACES ===== -->
        <!-- Opening { on same line (K&R) -->
        <module name="LeftCurly"/>
        <!-- Closing } on own line -->
        <module name="RightCurly"/>
        <!-- Always use braces for if/else/for/while/do -->
        <module name="NeedBraces">
            <property name="tokens" value="LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO"/>
        </module>

        <!-- ===== WHITESPACE ===== -->
        <module name="WhitespaceAfter">
            <property name="tokens" value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO, LITERAL_RETURN, LITERAL_SWITCH"/>
        </module>
        <module name="WhitespaceAround">
            <property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, DIV, DIV_ASSIGN, EQUAL, GE, GT, LAND, LE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, SL, SL_ASSIGN, SR, SR_ASSIGN, STAR, STAR_ASSIGN, TYPE_EXTENSION_AND"/>
            <property name="allowEmptyConstructors" value="true"/>
            <property name="allowEmptyMethods" value="true"/>
            <property name="allowEmptyTypes" value="true"/>
            <property name="allowEmptyLoops" value="true"/>
            <property name="allowEmptyLambdas" value="true"/>
        </module>
        <module name="NoWhitespaceBefore">
            <property name="tokens" value="COMMA, SEMI, POST_INC, POST_DEC"/>
            <property name="allowLineBreaks" value="true"/>
        </module>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="ParenPad"/>

        <!-- Blank lines between methods/constructors/inner classes (not between fields) -->
        <module name="EmptyLineSeparator">
            <property name="allowNoEmptyLineBetweenFields" value="true"/>
            <property name="allowMultipleEmptyLines" value="false"/>
            <property name="allowMultipleEmptyLinesInsideClassMembers" value="false"/>
            <property name="tokens" value="METHOD_DEF, CTOR_DEF, STATIC_INIT, INSTANCE_INIT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF"/>
        </module>

        <!-- ===== NAMING ===== -->
        <module name="TypeName"/>
        <module name="MethodName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>
        <module name="ConstantName"/>
        <module name="PackageName">
            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
        </module>

        <!-- ===== FINAL ===== -->
        <!-- Local variables and parameters that can be final must be declared final -->
        <module name="FinalLocalVariable">
            <property name="tokens" value="VARIABLE_DEF, PARAMETER_DEF"/>
            <property name="validateEnhancedForLoopVariable" value="true"/>
        </module>

        <!-- ===== METHOD SIZE ===== -->
        <!-- Methods should stay under 60 lines (blank lines and comments excluded) -->
        <module name="MethodLength">
            <property name="max" value="60"/>
            <property name="countEmpty" value="false"/>
        </module>
        <!-- Max 7 parameters per method or constructor -->
        <module name="ParameterNumber">
            <property name="max" value="7"/>
        </module>

        <!-- ===== ERROR PREVENTION ===== -->
        <!-- Unused local variables -->
        <module name="UnusedLocalVariable"/>
        <!-- equals() without hashCode() -->
        <module name="EqualsHashCode"/>
        <!-- switch without default -->
        <module name="MissingSwitchDefault"/>
        <!-- accidental switch fall-through -->
        <module name="FallThrough"/>
        <!-- assignment inside a condition: if (x = y) -->
        <module name="InnerAssignment"/>
        <!-- x == true, x != false -->
        <module name="SimplifyBooleanExpression"/>
        <!-- if (x) return true; else return false; -->
        <module name="SimplifyBooleanReturn"/>
        <!-- local variable or parameter shadows a field -->
        <module name="HiddenField">
            <property name="ignoreConstructorParameter" value="true"/>
            <property name="ignoreSetter" value="true"/>
        </module>

        <!-- ===== CODE STYLE ===== -->
        <!-- One statement per line -->
        <module name="OneStatementPerLine"/>
        <!-- No multiple variable declarations on one line -->
        <module name="MultipleVariableDeclarations"/>
        <!-- Only one top-level type per file -->
        <module name="OneTopLevelClass"/>
        <!-- Modifier order: public protected private abstract default static final ... -->
        <module name="ModifierOrder"/>
        <!-- No empty statements (stray semicolons) -->
        <module name="EmptyStatement"/>
        <!-- Use equals() for string comparison, not == -->
        <module name="StringLiteralEquality"/>
        <!-- No finalize() method -->
        <module name="NoFinalizer"/>
        <!-- C-style array declarations (String[] args, not String args[]) -->
        <module name="ArrayTypeStyle"/>
        <!-- Use L not l for long literals -->
        <module name="UpperEll"/>

    </module>
</module>