.checkstyle.xml

<?xml version="1.0"?>
<!-- https://checkstyle.org -->
<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN" "https://checkstyle.org/dtds/configuration_1_3.dtd">
<module name="Checker">
  <!-- Checker properties                                        -->
  <!-- See https://checkstyle.org/config.html#Checker_Properties -->
  <property name="charset" value="UTF-8"/>
  <property name="fileExtensions" value="java"/>
  <property name="localeLanguage" value="en"/>
  <property name="localeCountry" value="US"/>
  <property name="severity" value="error"/>
  <property name="tabWidth" value="4"/>

  <!-- Checks whether files end with a new line                       -->
  <!-- See https://checkstyle.org/config_misc.html#NewlineAtEndOfFile -->
  <module name="NewlineAtEndOfFile"/>

  <!-- Checks for size violations                   -->
  <!-- See https://checkstyle.org/config_sizes.html -->
  <module name="FileLength"/>
  <module name="LineLength">
    <property name="fileExtensions" value="java"/>
    <property name="max" value="120"/>
  </module>

  <!-- Checks for whitespace                             -->
  <!-- See https://checkstyle.org/config_whitespace.html -->
  <module name="FileTabCharacter"/>
  <module name="RegexpMultiline">
    <property name="format" value="\n[\t ]*\r?\n[\t ]*\r?\n"/>
    <property name="message" value="Multiple adjacent blank lines."/>
  </module>
  <module name="RegexpSingleline">
    <property name="format" value="\s+$"/>
    <property name="message" value="Line has trailing whitespace."/>
  </module>

  <!-- Checks for headers                            -->
  <!-- See https://checkstyle.org/config_header.html -->
  <!-- <module name="Header">
    <property name="fileExtensions" value="java"/>
    <property name="headerFile" value="LICENCE.txt"/>
  </module> -->

  <!-- Checks that a package-info.java file exists for each package  -->
  <!-- See https://checkstyle.org/config_javadoc.html#JavadocPackage -->
  <!-- <module name="JavadocPackage"/> -->

  <module name="TreeWalker">

    <!-- Checks for imports                             -->
    <!-- See https://checkstyle.org/config_imports.html -->
    <module name="AvoidStarImport"/>
    <module name="IllegalImport"/>
    <module name="ImportOrder">
      <!-- todo: replace 'com.example' import group -->
      <property name="groups" value="java,javax,*,com.mojang,net.minecraft,net.fabricmc,com.example"/>
      <property name="separated" value="true"/>
    </module>
    <module name="RedundantImport"/>
    <module name="UnusedImports"/>

    <!-- Checks for class design                       -->
    <!-- See https://checkstyle.org/config_design.html -->
    <module name="FinalClass"/>
    <module name="HideUtilityClassConstructor"/>
    <module name="OneTopLevelClass"/>

    <!-- Checks for annotations                            -->
    <!-- See https://checkstyle.org/config_annotation.html -->
    <module name="AnnotationLocation"/>
    <module name="MissingOverride"/>
    <module name="SuppressWarningsHolder"/>

    <!-- Checks for modifiers                             -->
    <!-- See https://checkstyle.org/config_modifiers.html -->
    <module name="ModifierOrder"/>
    <module name="RedundantModifier"/>

    <!-- Checks for common coding problems             -->
    <!-- See https://checkstyle.org/config_coding.html -->
    <module name="ArrayTrailingComma"/> <!-- cleaner diffs -->
    <module name="AvoidNoArgumentSuperConstructorCall"/>
    <module name="DefaultComesLast"/>
    <module name="EmptyStatement"/>
    <module name="EqualsAvoidNull"/>
    <module name="EqualsHashCode"/>
    <module name="MissingSwitchDefault"/>
    <module name="PackageDeclaration"/>
    <module name="SimplifyBooleanExpression"/>
    <module name="SimplifyBooleanReturn"/>
    <module name="StringLiteralEquality"/>
    <module name="UnnecessaryParentheses"/>
    <module name="UnnecessarySemicolonAfterOuterTypeDeclaration"/>
    <module name="UnnecessarySemicolonAfterTypeMemberDeclaration"/>
    <module name="UnnecessarySemicolonInTryWithResources"/>

    <!-- Checks for blocks, i.e. { ... }               -->
    <!-- See https://checkstyle.org/config_blocks.html -->
    <module name="AvoidNestedBlocks"/>
    <module name="EmptyBlock"/>
    <module name="EmptyCatchBlock"/>
    <!-- <module name="LeftCurly"/>-->
    <!-- <module name="NeedBraces"/>-->
    <!-- <module name="RightCurly"/>-->

    <!-- Checks for K&R brace styling                                  -->
    <!-- See https://en.wikipedia.org/wiki/Indentation_style#K&R_style -->
    <module name="LeftCurly"> <!-- braces on new line for class structure -->
      <property name="option" value="nl"/>
      <property name="tokens" value="ANNOTATION_DEF,CLASS_DEF,CTOR_DEF,ENUM_DEF,INTERFACE_DEF,METHOD_DEF,OBJBLOCK,RECORD_DEF"/>
    </module>
    <module name="LeftCurly"> <!-- braces at end of line within blocks -->
      <property name="option" value="eol"/>
      <property name="tokens" value="ENUM_CONSTANT_DEF,LAMBDA,LITERAL_CASE,LITERAL_CATCH,LITERAL_DEFAULT,LITERAL_DO,LITERAL_ELSE,LITERAL_FINALLY,LITERAL_FOR,LITERAL_IF,LITERAL_SWITCH,LITERAL_SYNCHRONIZED,LITERAL_TRY,LITERAL_WHILE,STATIC_INIT,COMPACT_CTOR_DEF"/>
    </module>
    <module name="RightCurly"/>

    <!-- Checks for naming conventions                 -->
    <!-- See https://checkstyle.org/config_naming.html -->
    <module name="CatchParameterName"/>
    <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"/>
    <module name="ParameterName"/>
    <module name="PatternVariableName"/>
    <module name="RecordComponentName"/>
    <module name="RecordTypeParameterName"/>
    <module name="StaticVariableName"/>
    <module name="TypeName"/>

    <!-- Checks for Javadoc comments                    -->
    <!-- See https://checkstyle.org/config_javadoc.html -->
    <module name="InvalidJavadocPosition"/>
    <module name="JavadocMethod"/>
    <module name="JavadocParagraph"/>
    <module name="JavadocStyle"/>
    <module name="JavadocType"/>
    <!-- <module name="MissingJavadocMethod"/> -->
    <!-- <module name="MissingJavadocPackage"/> -->
    <!-- <module name="MissingJavadocType"/> -->
    <module name="RequireEmptyLineBeforeBlockTagGroup"/>
    <module name="SingleLineJavadoc"/>

    <!-- Checks for whitespace                             -->
    <!-- See https://checkstyle.org/config_whitespace.html -->
    <module name="EmptyForIteratorPad"/>
    <module name="EmptyLineSeparator">
      <property name="allowMultipleEmptyLines" value="false"/>
      <property name="allowNoEmptyLineBetweenFields" value="true"/>
    </module>
    <module name="GenericWhitespace"/>
    <module name="MethodParamPad"/>
    <module name="NoWhitespaceAfter"/>
    <module name="NoWhitespaceBefore"/>
    <module name="OperatorWrap"/>
    <module name="ParenPad"/>
    <module name="SingleSpaceSeparator"/>
    <module name="TypecastParenPad"/>
    <module name="WhitespaceAfter"/>
    <module name="WhitespaceAround">
      <property name="allowEmptyCatches" value="true"/>
      <property name="allowEmptyConstructors" value="true"/>
      <property name="allowEmptyLambdas" value="true"/>
      <property name="allowEmptyLoops" value="true"/>
      <property name="allowEmptyMethods" value="true"/>
      <property name="allowEmptyTypes" value="true"/>
    </module>

    <!-- Miscellaneous checks                        -->
    <!-- See https://checkstyle.org/config_misc.html -->
    <module name="ArrayTypeStyle"/>
    <module name="CommentsIndentation"/>
    <module name="Indentation"/>
    <module name="OuterTypeFilename"/>
    <module name="TodoComment"/>
    <module name="UpperEll"/>

  </module>

  <!-- Excludes all 'module-info.java' files              -->
  <!-- See https://checkstyle.org/config_filefilters.html -->
  <module name="BeforeExecutionExclusionFileFilter">
    <property name="fileNamePattern" value="module\-info\.java$"/>
  </module>

  <!-- Enables suppression of audit events                                   -->
  <!-- See https://checkstyle.org/config_filters.html#SuppressWarningsFilter -->
  <module name="SuppressWarningsFilter"/>

</module>