From df88fd34cd952907de55225f92fda7da9d8ef473 Mon Sep 17 00:00:00 2001
From: Dai MIKURUBE <dmikurube@acm.org>
Date: Fri, 26 Apr 2024 17:32:49 +0900
Subject: [PATCH] Checkstyle with checkstyle 9.3

---
 build.gradle                                  |   6 +-
 config/checkstyle/README.md                   |   9 +-
 ...ssions.xml => checkstyle-suppressions.xml} |   1 +
 config/checkstyle/checkstyle.xml              | 540 +++++++++++-------
 config/checkstyle/google_checks.xml           | 535 ++++++++++-------
 gradle/libs.versions.toml                     |   2 +
 6 files changed, 674 insertions(+), 419 deletions(-)
 rename config/checkstyle/{suppressions.xml => checkstyle-suppressions.xml} (89%)

diff --git a/build.gradle b/build.gradle
index 37934292b..6cda7c317 100644
--- a/build.gradle
+++ b/build.gradle
@@ -173,11 +173,11 @@ tasks.withType(Checkstyle) {
 }
 
 checkstyle {
-    toolVersion "8.7"
+    toolVersion = libs.versions.checkstyle.get()
     configFile = file("${rootProject.projectDir}/config/checkstyle/checkstyle.xml")
     configProperties = [
-        "checkstyle.config.path": file("${projectDir}/config/checkstyle")
+        "org.checkstyle.google.suppressionfilter.config": file("${rootProject.projectDir}/config/checkstyle/checkstyle-suppressions.xml"),
     ]
     ignoreFailures = false
-    maxWarnings = 0  // https://github.com/gradle/gradle/issues/881
+    maxWarnings = 0
 }
diff --git a/config/checkstyle/README.md b/config/checkstyle/README.md
index efa34b9e0..403c7363c 100644
--- a/config/checkstyle/README.md
+++ b/config/checkstyle/README.md
@@ -1,12 +1,11 @@
 Checkstyle for the Embulk project
 ==================================
 
-* google_check.xml: Downloaded from: https://github.com/checkstyle/checkstyle/blob/master/src/main/resources/google_checks.xml
-     * Commit: 60f41e3c16e6c94b0bf8c2e5e4b4accf4ad394ab
+* google_check.xml: Downloaded from: https://github.com/checkstyle/checkstyle/blob/checkstyle-9.3/src/main/resources/google_checks.xml
+     * Commit: 5c1903792f8432243cc8ae5cd79a03a004d3c09c
 * checkstyle.xml: Customized from google_check.xml.
-    * To enable suppressions through suppressions.xml.
+    * To enable suppressions through checkstyle-suppressions.xml.
     * To enable suppressions with @SuppressWarnings.
-    * To accept package names with underscores.
     * To indent with 4-column spaces.
-    * To limit columns to 180 characters, which will be shortened later.
+    * To limit columns to 180 characters.
     * To reject unused imports.
diff --git a/config/checkstyle/suppressions.xml b/config/checkstyle/checkstyle-suppressions.xml
similarity index 89%
rename from config/checkstyle/suppressions.xml
rename to config/checkstyle/checkstyle-suppressions.xml
index 087253ac6..aefd4d6b2 100644
--- a/config/checkstyle/suppressions.xml
+++ b/config/checkstyle/checkstyle-suppressions.xml
@@ -8,6 +8,7 @@
   <suppress checks="JavadocMethod" files=".*"/>
   <suppress checks="JavadocParagraph" files=".*"/>
   <suppress checks="JavadocTagContinuationIndentation" files=".*"/>
+  <suppress checks="MissingJavadocType" files=".*"/>
   <suppress checks="SingleLineJavadoc" files=".*"/>
   <suppress checks="SummaryJavadoc" files=".*"/>
 </suppressions>
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
index e31da0870..c70b0c4ac 100644
--- a/config/checkstyle/checkstyle.xml
+++ b/config/checkstyle/checkstyle.xml
@@ -1,242 +1,368 @@
 <?xml version="1.0"?>
 <!DOCTYPE module PUBLIC
-          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
-          "http://checkstyle.sourceforge.net/dtds/configuration_1_3.dtd">
+          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+          "https://checkstyle.org/dtds/configuration_1_3.dtd">
 
 <!--
     Checkstyle configuration that checks the Google coding conventions from Google Java Style
-    that can be found at https://google.github.io/styleguide/javaguide.html.
+    that can be found at https://google.github.io/styleguide/javaguide.html
 
     Checkstyle is very configurable. Be sure to read the documentation at
-    http://checkstyle.sf.net (or in your downloaded distribution).
+    http://checkstyle.org (or in your downloaded distribution).
 
     To completely disable a check, just comment it out or delete it from the file.
+    To suppress certain violations please review suppression filters.
 
     Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
  -->
 
 <module name = "Checker">
-    <property name="charset" value="UTF-8"/>
+  <property name="charset" value="UTF-8"/>
 
-    <property name="severity" value="warning"/>
+  <property name="severity" value="warning"/>
 
-    <property name="fileExtensions" value="java, properties, xml"/>
+  <property name="fileExtensions" value="java, properties, xml"/>
+  <!-- Excludes all 'module-info.java' files              -->
+  <!-- See https://checkstyle.org/config_filefilters.html -->
+  <module name="BeforeExecutionExclusionFileFilter">
+    <property name="fileNamePattern" value="module\-info\.java$"/>
+  </module>
+  <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
+  <module name="SuppressionFilter">
+    <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
+           default="checkstyle-suppressions.xml" />
+    <property name="optional" value="false"/>
+  </module>
 
-    <module name="SuppressionFilter">
-        <property name="file" value="${checkstyle.config.path}/suppressions.xml"/>
-        <property name="optional" value="false"/>
-    </module>
+  <module name="SuppressWarningsFilter"/>
 
-    <module name="SuppressWarningsFilter" />
+  <!-- Checks for whitespace                               -->
+  <!-- See http://checkstyle.org/config_whitespace.html -->
+  <module name="FileTabCharacter">
+    <property name="eachLine" value="true"/>
+  </module>
 
-    <!-- Checks for whitespace                               -->
-    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
-    <module name="FileTabCharacter">
-        <property name="eachLine" value="true"/>
-    </module>
+  <module name="LineLength">
+    <property name="fileExtensions" value="java"/>
+    <property name="max" value="180"/>
+    <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+  </module>
 
-    <module name="TreeWalker">
-        <module name="OuterTypeFilename"/>
-        <module name="IllegalTokenText">
-            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
-            <property name="format" value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
-            <property name="message" value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
-        </module>
-        <module name="AvoidEscapedUnicodeCharacters">
-            <property name="allowEscapesForControlCharacters" value="true"/>
-            <property name="allowByTailComment" value="true"/>
-            <property name="allowNonPrintableEscapes" value="true"/>
-        </module>
-        <module name="LineLength">
-            <property name="max" value="180"/>
-            <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
-        </module>
-        <module name="AvoidStarImport"/>
-        <module name="OneTopLevelClass"/>
-        <module name="NoLineWrap"/>
-        <module name="EmptyBlock">
-            <property name="option" value="TEXT"/>
-            <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
-        </module>
-        <module name="NeedBraces"/>
-        <module name="LeftCurly"/>
-        <module name="RightCurly">
-            <property name="id" value="RightCurlySame"/>
-            <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_DO"/>
-        </module>
-        <module name="RightCurly">
-            <property name="id" value="RightCurlyAlone"/>
-            <property name="option" value="alone"/>
-            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT, INSTANCE_INIT"/>
-        </module>
-        <module name="WhitespaceAround">
-            <property name="allowEmptyConstructors" value="true"/>
-            <property name="allowEmptyMethods" value="true"/>
-            <property name="allowEmptyTypes" value="true"/>
-            <property name="allowEmptyLoops" value="true"/>
-            <message key="ws.notFollowed"
-             value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
-             <message key="ws.notPreceded"
-             value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
-        </module>
-        <module name="OneStatementPerLine"/>
-        <module name="MultipleVariableDeclarations"/>
-        <module name="ArrayTypeStyle"/>
-        <module name="MissingSwitchDefault"/>
-        <module name="FallThrough"/>
-        <module name="UpperEll"/>
-        <module name="ModifierOrder"/>
-        <module name="EmptyLineSeparator">
-            <property name="allowNoEmptyLineBetweenFields" value="true"/>
-        </module>
-        <module name="SeparatorWrap">
-            <property name="id" value="SeparatorWrapDot"/>
-            <property name="tokens" value="DOT"/>
-            <property name="option" value="nl"/>
-        </module>
-        <module name="SeparatorWrap">
-            <property name="id" value="SeparatorWrapComma"/>
-            <property name="tokens" value="COMMA"/>
-            <property name="option" value="EOL"/>
-        </module>
-        <module name="SeparatorWrap">
-            <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
-            <property name="id" value="SeparatorWrapEllipsis"/>
-            <property name="tokens" value="ELLIPSIS"/>
-            <property name="option" value="EOL"/>
-        </module>
-        <module name="SeparatorWrap">
-            <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
-            <property name="id" value="SeparatorWrapArrayDeclarator"/>
-            <property name="tokens" value="ARRAY_DECLARATOR"/>
-            <property name="option" value="EOL"/>
-        </module>
-        <module name="SeparatorWrap">
-            <property name="id" value="SeparatorWrapMethodRef"/>
-            <property name="tokens" value="METHOD_REF"/>
-            <property name="option" value="nl"/>
-        </module>
-        <module name="TypeName">
-            <message key="name.invalidPattern"
+  <module name="TreeWalker">
+    <module name="OuterTypeFilename"/>
+    <module name="IllegalTokenText">
+      <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+      <property name="format"
+               value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+      <property name="message"
+               value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+    </module>
+    <module name="AvoidEscapedUnicodeCharacters">
+      <property name="allowEscapesForControlCharacters" value="true"/>
+      <property name="allowByTailComment" value="true"/>
+      <property name="allowNonPrintableEscapes" value="true"/>
+    </module>
+    <module name="AvoidStarImport"/>
+    <module name="OneTopLevelClass"/>
+    <module name="NoLineWrap">
+      <property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT"/>
+    </module>
+    <module name="EmptyBlock">
+      <property name="option" value="TEXT"/>
+      <property name="tokens"
+               value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+    </module>
+    <module name="NeedBraces">
+      <property name="tokens"
+               value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF, LITERAL_WHILE"/>
+    </module>
+    <module name="LeftCurly">
+      <property name="tokens"
+               value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF,
+                    INTERFACE_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, METHOD_DEF,
+                    OBJBLOCK, STATIC_INIT, RECORD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlySame"/>
+      <property name="tokens"
+               value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+    </module>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlyAlone"/>
+      <property name="option" value="alone"/>
+      <property name="tokens"
+               value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="SuppressionXpathSingleFilter">
+      <!-- suppresion is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
+      <property name="id" value="RightCurlyAlone"/>
+      <property name="query" value="//RCURLY[parent::SLIST[count(./*)=1]
+                                     or preceding-sibling::*[last()][self::LCURLY]]"/>
+    </module>
+    <module name="WhitespaceAfter">
+      <property name="tokens"
+               value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, DO_WHILE"/>
+    </module>
+    <module name="WhitespaceAround">
+      <property name="allowEmptyConstructors" value="true"/>
+      <property name="allowEmptyLambdas" value="true"/>
+      <property name="allowEmptyMethods" value="true"/>
+      <property name="allowEmptyTypes" value="true"/>
+      <property name="allowEmptyLoops" value="true"/>
+      <property name="ignoreEnhancedForColon" value="false"/>
+      <property name="tokens"
+               value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR,
+                    BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND,
+                    LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY,
+                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED,
+                    LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN,
+                    NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
+                    SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
+      <message key="ws.notFollowed"
+              value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+      <message key="ws.notPreceded"
+              value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+    </module>
+    <module name="OneStatementPerLine"/>
+    <module name="MultipleVariableDeclarations"/>
+    <module name="ArrayTypeStyle"/>
+    <module name="MissingSwitchDefault"/>
+    <module name="FallThrough"/>
+    <module name="UpperEll"/>
+    <module name="ModifierOrder"/>
+    <module name="EmptyLineSeparator">
+      <property name="tokens"
+               value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+      <property name="allowNoEmptyLineBetweenFields" value="true"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapDot"/>
+      <property name="tokens" value="DOT"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapComma"/>
+      <property name="tokens" value="COMMA"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/259 -->
+      <property name="id" value="SeparatorWrapEllipsis"/>
+      <property name="tokens" value="ELLIPSIS"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/258 -->
+      <property name="id" value="SeparatorWrapArrayDeclarator"/>
+      <property name="tokens" value="ARRAY_DECLARATOR"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapMethodRef"/>
+      <property name="tokens" value="METHOD_REF"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="PackageName">
+      <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+      <message key="name.invalidPattern"
+             value="Package name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="TypeName">
+      <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    ANNOTATION_DEF, RECORD_DEF"/>
+      <message key="name.invalidPattern"
              value="Type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="MemberName">
-            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="MemberName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+      <message key="name.invalidPattern"
              value="Member name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="ParameterName">
-            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="ParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
              value="Parameter name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="CatchParameterName">
-            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="LambdaParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="CatchParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
              value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="LocalVariableName">
-            <property name="tokens" value="VARIABLE_DEF"/>
-            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="LocalVariableName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
              value="Local variable name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="ClassTypeParameterName">
-            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="PatternVariableName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Pattern variable name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="ClassTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
              value="Class type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="MethodTypeParameterName">
-            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="RecordComponentName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+               value="Record component name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="RecordTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+               value="Record type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="MethodTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
              value="Method type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="InterfaceTypeParameterName">
-            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="InterfaceTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
              value="Interface type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="NoFinalizer"/>
-        <module name="GenericWhitespace">
-            <message key="ws.followed"
+    </module>
+    <module name="NoFinalizer"/>
+    <module name="GenericWhitespace">
+      <message key="ws.followed"
              value="GenericWhitespace ''{0}'' is followed by whitespace."/>
-             <message key="ws.preceded"
+      <message key="ws.preceded"
              value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
-             <message key="ws.illegalFollow"
+      <message key="ws.illegalFollow"
              value="GenericWhitespace ''{0}'' should followed by whitespace."/>
-             <message key="ws.notPreceded"
+      <message key="ws.notPreceded"
              value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
-        </module>
-        <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>
-        <module name="AbbreviationAsWordInName">
-            <property name="ignoreFinal" value="false"/>
-            <property name="allowedAbbreviationLength" value="1"/>
-        </module>
-        <module name="OverloadMethodsDeclarationOrder"/>
-        <module name="VariableDeclarationUsageDistance"/>
-        <module name="CustomImportOrder">
-            <property name="sortImportsInGroupAlphabetically" value="true"/>
-            <property name="separateLineBetweenGroups" value="true"/>
-            <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
-        </module>
-        <module name="MethodParamPad"/>
-        <module name="NoWhitespaceBefore">
-          <property name="tokens" value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
-            <property name="allowLineBreaks" value="true"/>
-        </module>
-        <module name="ParenPad"/>
-        <module name="OperatorWrap">
-            <property name="option" value="NL"/>
-            <property name="tokens" value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
-        </module>
-        <module name="AnnotationLocation">
-            <property name="id" value="AnnotationLocationMostCases"/>
-            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
-        </module>
-        <module name="AnnotationLocation">
-            <property name="id" value="AnnotationLocationVariables"/>
-            <property name="tokens" value="VARIABLE_DEF"/>
-            <property name="allowSamelineMultipleAnnotations" value="true"/>
-        </module>
-        <module name="NonEmptyAtclauseDescription"/>
-        <module name="JavadocTagContinuationIndentation"/>
-        <module name="SummaryJavadoc">
-            <property name="forbiddenSummaryFragments" value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
-        </module>
-        <module name="JavadocParagraph"/>
-        <module name="AtclauseOrder">
-            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
-            <property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
-        </module>
-        <module name="JavadocMethod">
-            <property name="scope" value="public"/>
-            <property name="allowMissingParamTags" value="true"/>
-            <property name="allowMissingThrowsTags" value="true"/>
-            <property name="allowMissingReturnTag" value="true"/>
-            <property name="minLineCount" value="2"/>
-            <property name="allowedAnnotations" value="Override, Test"/>
-            <property name="allowThrowsTagsForSubclasses" value="true"/>
-        </module>
-        <module name="MethodName">
-            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="Indentation">
+      <property name="basicOffset" value="4"/>
+      <property name="braceAdjustment" value="4"/>
+      <property name="caseIndent" value="4"/>
+      <property name="throwsIndent" value="8"/>
+      <property name="lineWrappingIndentation" value="8"/>
+      <property name="arrayInitIndent" value="4"/>
+    </module>
+    <module name="AbbreviationAsWordInName">
+      <property name="ignoreFinal" value="false"/>
+      <property name="allowedAbbreviationLength" value="0"/>
+      <property name="tokens"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, ANNOTATION_FIELD_DEF,
+                    PARAMETER_DEF, VARIABLE_DEF, METHOD_DEF, PATTERN_VARIABLE_DEF, RECORD_DEF,
+                    RECORD_COMPONENT_DEF"/>
+    </module>
+    <module name="NoWhitespaceBeforeCaseDefaultColon"/>
+    <module name="OverloadMethodsDeclarationOrder"/>
+    <module name="VariableDeclarationUsageDistance"/>
+    <module name="CustomImportOrder">
+      <property name="sortImportsInGroupAlphabetically" value="true"/>
+      <property name="separateLineBetweenGroups" value="true"/>
+      <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+      <property name="tokens" value="IMPORT, STATIC_IMPORT, PACKAGE_DEF"/>
+    </module>
+    <module name="MethodParamPad">
+      <property name="tokens"
+               value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF,
+                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF, RECORD_DEF"/>
+    </module>
+    <module name="NoWhitespaceBefore">
+      <property name="tokens"
+               value="COMMA, SEMI, POST_INC, POST_DEC, DOT,
+                    LABELED_STAT, METHOD_REF"/>
+      <property name="allowLineBreaks" value="true"/>
+    </module>
+    <module name="ParenPad">
+      <property name="tokens"
+               value="ANNOTATION, ANNOTATION_FIELD_DEF, CTOR_CALL, CTOR_DEF, DOT, ENUM_CONSTANT_DEF,
+                    EXPR, LITERAL_CATCH, LITERAL_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_WHILE, METHOD_CALL,
+                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL, LAMBDA,
+                    RECORD_DEF"/>
+    </module>
+    <module name="OperatorWrap">
+      <property name="option" value="NL"/>
+      <property name="tokens"
+               value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF,
+                    TYPE_EXTENSION_AND "/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationMostCases"/>
+      <property name="tokens"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF,
+                      RECORD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationVariables"/>
+      <property name="tokens" value="VARIABLE_DEF"/>
+      <property name="allowSamelineMultipleAnnotations" value="true"/>
+    </module>
+    <module name="NonEmptyAtclauseDescription"/>
+    <module name="InvalidJavadocPosition"/>
+    <module name="JavadocTagContinuationIndentation"/>
+    <module name="SummaryJavadoc">
+      <property name="forbiddenSummaryFragments"
+               value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+    </module>
+    <module name="JavadocParagraph"/>
+    <module name="RequireEmptyLineBeforeBlockTagGroup"/>
+    <module name="AtclauseOrder">
+      <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+      <property name="target"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+    </module>
+    <module name="JavadocMethod">
+      <property name="accessModifiers" value="public"/>
+      <property name="allowMissingParamTags" value="true"/>
+      <property name="allowMissingReturnTag" value="true"/>
+      <property name="allowedAnnotations" value="Override, Test"/>
+      <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="MissingJavadocMethod">
+      <property name="scope" value="public"/>
+      <property name="minLineCount" value="2"/>
+      <property name="allowedAnnotations" value="Override, Test"/>
+      <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF,
+                                   COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="MissingJavadocType">
+      <property name="scope" value="protected"/>
+      <property name="tokens"
+                value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                      RECORD_DEF, ANNOTATION_DEF"/>
+      <property name="excludeScope" value="nothing"/>
+    </module>
+    <module name="MethodName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+      <message key="name.invalidPattern"
              value="Method name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="SingleLineJavadoc">
-            <property name="ignoreInlineTags" value="false"/>
-        </module>
-        <module name="EmptyCatchBlock">
-            <property name="exceptionVariableName" value="expected"/>
-        </module>
-        <module name="CommentsIndentation"/>
-        <module name="SuppressWarningsHolder" />
-        <module name="UnusedImports"/>
     </module>
+    <module name="SingleLineJavadoc"/>
+    <module name="EmptyCatchBlock">
+      <property name="exceptionVariableName" value="expected"/>
+    </module>
+    <module name="CommentsIndentation">
+      <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
+    </module>
+    <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
+    <module name="SuppressionXpathFilter">
+      <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
+             default="checkstyle-xpath-suppressions.xml" />
+      <property name="optional" value="true"/>
+    </module>
+    <module name="SuppressWarningsHolder"/>
+    <module name="UnusedImports"/>
+  </module>
 </module>
diff --git a/config/checkstyle/google_checks.xml b/config/checkstyle/google_checks.xml
index a6fc40b5f..515a844ac 100644
--- a/config/checkstyle/google_checks.xml
+++ b/config/checkstyle/google_checks.xml
@@ -1,237 +1,364 @@
 <?xml version="1.0"?>
 <!DOCTYPE module PUBLIC
-          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
-          "http://checkstyle.sourceforge.net/dtds/configuration_1_3.dtd">
+          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+          "https://checkstyle.org/dtds/configuration_1_3.dtd">
 
 <!--
     Checkstyle configuration that checks the Google coding conventions from Google Java Style
-    that can be found at https://google.github.io/styleguide/javaguide.html.
+    that can be found at https://google.github.io/styleguide/javaguide.html
 
     Checkstyle is very configurable. Be sure to read the documentation at
-    http://checkstyle.sf.net (or in your downloaded distribution).
+    http://checkstyle.org (or in your downloaded distribution).
 
     To completely disable a check, just comment it out or delete it from the file.
+    To suppress certain violations please review suppression filters.
 
     Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
  -->
 
 <module name = "Checker">
-    <property name="charset" value="UTF-8"/>
+  <property name="charset" value="UTF-8"/>
 
-    <property name="severity" value="warning"/>
+  <property name="severity" value="warning"/>
 
-    <property name="fileExtensions" value="java, properties, xml"/>
-    <!-- Checks for whitespace                               -->
-    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
-    <module name="FileTabCharacter">
-        <property name="eachLine" value="true"/>
-    </module>
+  <property name="fileExtensions" value="java, properties, xml"/>
+  <!-- Excludes all 'module-info.java' files              -->
+  <!-- See https://checkstyle.org/config_filefilters.html -->
+  <module name="BeforeExecutionExclusionFileFilter">
+    <property name="fileNamePattern" value="module\-info\.java$"/>
+  </module>
+  <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
+  <module name="SuppressionFilter">
+    <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
+           default="checkstyle-suppressions.xml" />
+    <property name="optional" value="true"/>
+  </module>
+
+  <!-- Checks for whitespace                               -->
+  <!-- See http://checkstyle.org/config_whitespace.html -->
+  <module name="FileTabCharacter">
+    <property name="eachLine" value="true"/>
+  </module>
 
-    <module name="TreeWalker">
-        <module name="OuterTypeFilename"/>
-        <module name="IllegalTokenText">
-            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
-            <property name="format" value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
-            <property name="message" value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
-        </module>
-        <module name="AvoidEscapedUnicodeCharacters">
-            <property name="allowEscapesForControlCharacters" value="true"/>
-            <property name="allowByTailComment" value="true"/>
-            <property name="allowNonPrintableEscapes" value="true"/>
-        </module>
-        <module name="LineLength">
-            <property name="max" value="100"/>
-            <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
-        </module>
-        <module name="AvoidStarImport"/>
-        <module name="OneTopLevelClass"/>
-        <module name="NoLineWrap"/>
-        <module name="EmptyBlock">
-            <property name="option" value="TEXT"/>
-            <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
-        </module>
-        <module name="NeedBraces"/>
-        <module name="LeftCurly"/>
-        <module name="RightCurly">
-            <property name="id" value="RightCurlySame"/>
-            <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_DO"/>
-        </module>
-        <module name="RightCurly">
-            <property name="id" value="RightCurlyAlone"/>
-            <property name="option" value="alone"/>
-            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT, INSTANCE_INIT"/>
-        </module>
-        <module name="WhitespaceAround">
-            <property name="allowEmptyConstructors" value="true"/>
-            <property name="allowEmptyMethods" value="true"/>
-            <property name="allowEmptyTypes" value="true"/>
-            <property name="allowEmptyLoops" value="true"/>
-            <message key="ws.notFollowed"
-             value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
-             <message key="ws.notPreceded"
-             value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
-        </module>
-        <module name="OneStatementPerLine"/>
-        <module name="MultipleVariableDeclarations"/>
-        <module name="ArrayTypeStyle"/>
-        <module name="MissingSwitchDefault"/>
-        <module name="FallThrough"/>
-        <module name="UpperEll"/>
-        <module name="ModifierOrder"/>
-        <module name="EmptyLineSeparator">
-            <property name="allowNoEmptyLineBetweenFields" value="true"/>
-        </module>
-        <module name="SeparatorWrap">
-            <property name="id" value="SeparatorWrapDot"/>
-            <property name="tokens" value="DOT"/>
-            <property name="option" value="nl"/>
-        </module>
-        <module name="SeparatorWrap">
-            <property name="id" value="SeparatorWrapComma"/>
-            <property name="tokens" value="COMMA"/>
-            <property name="option" value="EOL"/>
-        </module>
-        <module name="SeparatorWrap">
-            <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
-            <property name="id" value="SeparatorWrapEllipsis"/>
-            <property name="tokens" value="ELLIPSIS"/>
-            <property name="option" value="EOL"/>
-        </module>
-        <module name="SeparatorWrap">
-            <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
-            <property name="id" value="SeparatorWrapArrayDeclarator"/>
-            <property name="tokens" value="ARRAY_DECLARATOR"/>
-            <property name="option" value="EOL"/>
-        </module>
-        <module name="SeparatorWrap">
-            <property name="id" value="SeparatorWrapMethodRef"/>
-            <property name="tokens" value="METHOD_REF"/>
-            <property name="option" value="nl"/>
-        </module>
-        <module name="PackageName">
-            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
-            <message key="name.invalidPattern"
+  <module name="LineLength">
+    <property name="fileExtensions" value="java"/>
+    <property name="max" value="100"/>
+    <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+  </module>
+
+  <module name="TreeWalker">
+    <module name="OuterTypeFilename"/>
+    <module name="IllegalTokenText">
+      <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+      <property name="format"
+               value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+      <property name="message"
+               value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+    </module>
+    <module name="AvoidEscapedUnicodeCharacters">
+      <property name="allowEscapesForControlCharacters" value="true"/>
+      <property name="allowByTailComment" value="true"/>
+      <property name="allowNonPrintableEscapes" value="true"/>
+    </module>
+    <module name="AvoidStarImport"/>
+    <module name="OneTopLevelClass"/>
+    <module name="NoLineWrap">
+      <property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT"/>
+    </module>
+    <module name="EmptyBlock">
+      <property name="option" value="TEXT"/>
+      <property name="tokens"
+               value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+    </module>
+    <module name="NeedBraces">
+      <property name="tokens"
+               value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF, LITERAL_WHILE"/>
+    </module>
+    <module name="LeftCurly">
+      <property name="tokens"
+               value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF,
+                    INTERFACE_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, METHOD_DEF,
+                    OBJBLOCK, STATIC_INIT, RECORD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlySame"/>
+      <property name="tokens"
+               value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+    </module>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlyAlone"/>
+      <property name="option" value="alone"/>
+      <property name="tokens"
+               value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="SuppressionXpathSingleFilter">
+      <!-- suppresion is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
+      <property name="id" value="RightCurlyAlone"/>
+      <property name="query" value="//RCURLY[parent::SLIST[count(./*)=1]
+                                     or preceding-sibling::*[last()][self::LCURLY]]"/>
+    </module>
+    <module name="WhitespaceAfter">
+      <property name="tokens"
+               value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, DO_WHILE"/>
+    </module>
+    <module name="WhitespaceAround">
+      <property name="allowEmptyConstructors" value="true"/>
+      <property name="allowEmptyLambdas" value="true"/>
+      <property name="allowEmptyMethods" value="true"/>
+      <property name="allowEmptyTypes" value="true"/>
+      <property name="allowEmptyLoops" value="true"/>
+      <property name="ignoreEnhancedForColon" value="false"/>
+      <property name="tokens"
+               value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR,
+                    BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND,
+                    LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY,
+                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED,
+                    LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN,
+                    NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
+                    SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
+      <message key="ws.notFollowed"
+              value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+      <message key="ws.notPreceded"
+              value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+    </module>
+    <module name="OneStatementPerLine"/>
+    <module name="MultipleVariableDeclarations"/>
+    <module name="ArrayTypeStyle"/>
+    <module name="MissingSwitchDefault"/>
+    <module name="FallThrough"/>
+    <module name="UpperEll"/>
+    <module name="ModifierOrder"/>
+    <module name="EmptyLineSeparator">
+      <property name="tokens"
+               value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+      <property name="allowNoEmptyLineBetweenFields" value="true"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapDot"/>
+      <property name="tokens" value="DOT"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapComma"/>
+      <property name="tokens" value="COMMA"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/259 -->
+      <property name="id" value="SeparatorWrapEllipsis"/>
+      <property name="tokens" value="ELLIPSIS"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/258 -->
+      <property name="id" value="SeparatorWrapArrayDeclarator"/>
+      <property name="tokens" value="ARRAY_DECLARATOR"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapMethodRef"/>
+      <property name="tokens" value="METHOD_REF"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="PackageName">
+      <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+      <message key="name.invalidPattern"
              value="Package name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="TypeName">
-            <message key="name.invalidPattern"
+    </module>
+    <module name="TypeName">
+      <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    ANNOTATION_DEF, RECORD_DEF"/>
+      <message key="name.invalidPattern"
              value="Type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="MemberName">
-            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="MemberName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+      <message key="name.invalidPattern"
              value="Member name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="ParameterName">
-            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="ParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
              value="Parameter name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="CatchParameterName">
-            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="LambdaParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="CatchParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
              value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="LocalVariableName">
-            <property name="tokens" value="VARIABLE_DEF"/>
-            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="LocalVariableName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
              value="Local variable name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="ClassTypeParameterName">
-            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="PatternVariableName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Pattern variable name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="ClassTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
              value="Class type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="MethodTypeParameterName">
-            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="RecordComponentName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+               value="Record component name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="RecordTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+               value="Record type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="MethodTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
              value="Method type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="InterfaceTypeParameterName">
-            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="InterfaceTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
              value="Interface type name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="NoFinalizer"/>
-        <module name="GenericWhitespace">
-            <message key="ws.followed"
+    </module>
+    <module name="NoFinalizer"/>
+    <module name="GenericWhitespace">
+      <message key="ws.followed"
              value="GenericWhitespace ''{0}'' is followed by whitespace."/>
-             <message key="ws.preceded"
+      <message key="ws.preceded"
              value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
-             <message key="ws.illegalFollow"
+      <message key="ws.illegalFollow"
              value="GenericWhitespace ''{0}'' should followed by whitespace."/>
-             <message key="ws.notPreceded"
+      <message key="ws.notPreceded"
              value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
-        </module>
-        <module name="Indentation">
-            <property name="basicOffset" value="2"/>
-            <property name="braceAdjustment" value="0"/>
-            <property name="caseIndent" value="2"/>
-            <property name="throwsIndent" value="4"/>
-            <property name="lineWrappingIndentation" value="4"/>
-            <property name="arrayInitIndent" value="2"/>
-        </module>
-        <module name="AbbreviationAsWordInName">
-            <property name="ignoreFinal" value="false"/>
-            <property name="allowedAbbreviationLength" value="1"/>
-        </module>
-        <module name="OverloadMethodsDeclarationOrder"/>
-        <module name="VariableDeclarationUsageDistance"/>
-        <module name="CustomImportOrder">
-            <property name="sortImportsInGroupAlphabetically" value="true"/>
-            <property name="separateLineBetweenGroups" value="true"/>
-            <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
-        </module>
-        <module name="MethodParamPad"/>
-        <module name="NoWhitespaceBefore">
-          <property name="tokens" value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
-            <property name="allowLineBreaks" value="true"/>
-        </module>
-        <module name="ParenPad"/>
-        <module name="OperatorWrap">
-            <property name="option" value="NL"/>
-            <property name="tokens" value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
-        </module>
-        <module name="AnnotationLocation">
-            <property name="id" value="AnnotationLocationMostCases"/>
-            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
-        </module>
-        <module name="AnnotationLocation">
-            <property name="id" value="AnnotationLocationVariables"/>
-            <property name="tokens" value="VARIABLE_DEF"/>
-            <property name="allowSamelineMultipleAnnotations" value="true"/>
-        </module>
-        <module name="NonEmptyAtclauseDescription"/>
-        <module name="JavadocTagContinuationIndentation"/>
-        <module name="SummaryJavadoc">
-            <property name="forbiddenSummaryFragments" value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
-        </module>
-        <module name="JavadocParagraph"/>
-        <module name="AtclauseOrder">
-            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
-            <property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
-        </module>
-        <module name="JavadocMethod">
-            <property name="scope" value="public"/>
-            <property name="allowMissingParamTags" value="true"/>
-            <property name="allowMissingThrowsTags" value="true"/>
-            <property name="allowMissingReturnTag" value="true"/>
-            <property name="minLineCount" value="2"/>
-            <property name="allowedAnnotations" value="Override, Test"/>
-            <property name="allowThrowsTagsForSubclasses" value="true"/>
-        </module>
-        <module name="MethodName">
-            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
-            <message key="name.invalidPattern"
+    </module>
+    <module name="Indentation">
+      <property name="basicOffset" value="2"/>
+      <property name="braceAdjustment" value="2"/>
+      <property name="caseIndent" value="2"/>
+      <property name="throwsIndent" value="4"/>
+      <property name="lineWrappingIndentation" value="4"/>
+      <property name="arrayInitIndent" value="2"/>
+    </module>
+    <module name="AbbreviationAsWordInName">
+      <property name="ignoreFinal" value="false"/>
+      <property name="allowedAbbreviationLength" value="0"/>
+      <property name="tokens"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, ANNOTATION_FIELD_DEF,
+                    PARAMETER_DEF, VARIABLE_DEF, METHOD_DEF, PATTERN_VARIABLE_DEF, RECORD_DEF,
+                    RECORD_COMPONENT_DEF"/>
+    </module>
+    <module name="NoWhitespaceBeforeCaseDefaultColon"/>
+    <module name="OverloadMethodsDeclarationOrder"/>
+    <module name="VariableDeclarationUsageDistance"/>
+    <module name="CustomImportOrder">
+      <property name="sortImportsInGroupAlphabetically" value="true"/>
+      <property name="separateLineBetweenGroups" value="true"/>
+      <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+      <property name="tokens" value="IMPORT, STATIC_IMPORT, PACKAGE_DEF"/>
+    </module>
+    <module name="MethodParamPad">
+      <property name="tokens"
+               value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF,
+                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF, RECORD_DEF"/>
+    </module>
+    <module name="NoWhitespaceBefore">
+      <property name="tokens"
+               value="COMMA, SEMI, POST_INC, POST_DEC, DOT,
+                    LABELED_STAT, METHOD_REF"/>
+      <property name="allowLineBreaks" value="true"/>
+    </module>
+    <module name="ParenPad">
+      <property name="tokens"
+               value="ANNOTATION, ANNOTATION_FIELD_DEF, CTOR_CALL, CTOR_DEF, DOT, ENUM_CONSTANT_DEF,
+                    EXPR, LITERAL_CATCH, LITERAL_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_WHILE, METHOD_CALL,
+                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL, LAMBDA,
+                    RECORD_DEF"/>
+    </module>
+    <module name="OperatorWrap">
+      <property name="option" value="NL"/>
+      <property name="tokens"
+               value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF,
+                    TYPE_EXTENSION_AND "/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationMostCases"/>
+      <property name="tokens"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF,
+                      RECORD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationVariables"/>
+      <property name="tokens" value="VARIABLE_DEF"/>
+      <property name="allowSamelineMultipleAnnotations" value="true"/>
+    </module>
+    <module name="NonEmptyAtclauseDescription"/>
+    <module name="InvalidJavadocPosition"/>
+    <module name="JavadocTagContinuationIndentation"/>
+    <module name="SummaryJavadoc">
+      <property name="forbiddenSummaryFragments"
+               value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+    </module>
+    <module name="JavadocParagraph"/>
+    <module name="RequireEmptyLineBeforeBlockTagGroup"/>
+    <module name="AtclauseOrder">
+      <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+      <property name="target"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+    </module>
+    <module name="JavadocMethod">
+      <property name="accessModifiers" value="public"/>
+      <property name="allowMissingParamTags" value="true"/>
+      <property name="allowMissingReturnTag" value="true"/>
+      <property name="allowedAnnotations" value="Override, Test"/>
+      <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="MissingJavadocMethod">
+      <property name="scope" value="public"/>
+      <property name="minLineCount" value="2"/>
+      <property name="allowedAnnotations" value="Override, Test"/>
+      <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF,
+                                   COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="MissingJavadocType">
+      <property name="scope" value="protected"/>
+      <property name="tokens"
+                value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                      RECORD_DEF, ANNOTATION_DEF"/>
+      <property name="excludeScope" value="nothing"/>
+    </module>
+    <module name="MethodName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+      <message key="name.invalidPattern"
              value="Method name ''{0}'' must match pattern ''{1}''."/>
-        </module>
-        <module name="SingleLineJavadoc">
-            <property name="ignoreInlineTags" value="false"/>
-        </module>
-        <module name="EmptyCatchBlock">
-            <property name="exceptionVariableName" value="expected"/>
-        </module>
-        <module name="CommentsIndentation"/>
     </module>
+    <module name="SingleLineJavadoc"/>
+    <module name="EmptyCatchBlock">
+      <property name="exceptionVariableName" value="expected"/>
+    </module>
+    <module name="CommentsIndentation">
+      <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
+    </module>
+    <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
+    <module name="SuppressionXpathFilter">
+      <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
+             default="checkstyle-xpath-suppressions.xml" />
+      <property name="optional" value="true"/>
+    </module>
+  </module>
 </module>
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index c7b59b408..e43f3adf4 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -16,6 +16,8 @@ jackson = "2.16.2"
 embulk-util-file = "0.1.5"
 embulk-util-timestamp = "0.2.2"
 
+checkstyle = "9.3"
+
 [libraries]
 
 embulk-spi = { group = "org.embulk", name = "embulk-spi", version.ref = "embulk-spi" }