From 5afc7951e20c37f39ad76e45f8bcca3925425b15 Mon Sep 17 00:00:00 2001
From: Kacper Kafara <kacperkafara@gmail.com>
Date: Wed, 13 Apr 2022 16:48:46 +0200
Subject: [PATCH] chore: add Java linter (#14)

* chore: Add Checkstyle configuration by Google (as 2019)

* chore: Setup dir structure as expected by Checkstyle plugin

* chore: Add checkstyle plugin to gradle

* chore: set path to configuration for gralde plugin

* fix: remove missing checkstyle options
---
 build.gradle                     |   5 +
 config/checkstyle/checkstyle.xml | 361 +++++++++++++++++++++++++++++++
 2 files changed, 366 insertions(+)
 create mode 100644 config/checkstyle/checkstyle.xml

diff --git a/build.gradle b/build.gradle
index 94236a0a..3c2909a4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,6 +3,7 @@ plugins {
     id 'application'
     id 'org.openjfx.javafxplugin' version '0.0.10'
     id 'org.beryx.jlink' version '2.24.1'
+    id 'checkstyle'
 }
 
 group 'io.rpg'
@@ -19,6 +20,10 @@ ext {
 sourceCompatibility = '17'
 targetCompatibility = '17'
 
+checkstyle {
+    configFile = file('config/checkstyle/checkstyle.xml')
+}
+
 tasks.withType(JavaCompile) {
     options.encoding = 'UTF-8'
 }
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
new file mode 100644
index 00000000..f160a312
--- /dev/null
+++ b/config/checkstyle/checkstyle.xml
@@ -0,0 +1,361 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+          "-//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
+    Checkstyle is very configurable. Be sure to read the documentation at
+    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="severity" value="warning"/>
+
+  <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="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_IF, LITERAL_ELSE"/>
+    </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, LITERAL_CASE, LITERAL_DEFAULT,
+                    LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF,
+                    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_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, LAND,
+                    LCURLY, LE, LITERAL_DO, LITERAL_ELSE,
+                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN,
+                    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="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"
+             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]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="LambdaParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <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]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="LocalVariableName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="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]$)"/>
+      <message key="name.invalidPattern"
+             value="Class type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+<!--    <module name="RecordComponentName">-->
+<!--      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>-->
+<!--      <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"
+             value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="NoFinalizer"/>
+    <module name="GenericWhitespace">
+      <message key="ws.followed"
+             value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+      <message key="ws.preceded"
+             value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+      <message key="ws.illegalFollow"
+             value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+      <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="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_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
+                    LITERAL_WHILE, METHOD_CALL,
+                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL,
+                    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_]*$"/>
+      <message key="name.invalidPattern"
+             value="Method name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="SingleLineJavadoc"/>
+    <module name="EmptyCatchBlock">
+      <property name="exceptionVariableName" value="expected"/>
+    </module>
+    <module name="CommentsIndentation">
+      <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
+    </module>
+    <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
+    <module name="SuppressionXpathFilter">
+      <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
+             default="checkstyle-xpath-suppressions.xml" />
+      <property name="optional" value="true"/>
+    </module>
+  </module>
+</module>