Collection of custom XPath CheckStyle rules

checkstyle.xml

<!-- This is a collection of useful CheckStyle XPath rules -->
<!-- See https://checkstyle.sourceforge.io/checks/coding/matchxpath.html -->
<!-- Some useful rules can also be found in https://github.com/checkstyle/checkstyle/blob/master/config/checkstyle-checks.xml -->

<!-- Forbids usage of Collectors#toList in favour of Stream#toList -->
<module name="MatchXpath">
  <property name="query" value="//METHOD_CALL[./DOT/IDENT[@text='collect'] and ..//METHOD_CALL//IDENT[@text='toList']]"/>
  <message key="matchxpath.match" value="Use Stream#toList() method to collect items."/>
</module>

<!-- Forbids redundant Stream#collect and Stream#toList operations before Stream#forEach -->
<module name="MatchXpath">
  <property name="query" value="//METHOD_CALL/DOT[./IDENT[@text='forEach'] and ./METHOD_CALL/DOT/IDENT[@text='toList']]"/>
  <message key="matchxpath.match" value="Collect before forEach is redundant."/>
</module>
<module name="MatchXpath">
  <property name="query" value="//METHOD_CALL/DOT[./IDENT[@text='forEach'] and ./METHOD_CALL/DOT/IDENT[@text='collect']]"/>
  <message key="matchxpath.match" value="Collect before forEach is redundant."/>
</module>

<!-- Makes sure that utility classes (with only static methods) are final -->
<module name="MatchXpath">
  <property name="query"
            value="//CLASS_DEF[.//METHOD_DEF and count(.//METHOD_DEF[not(./MODIFIERS/LITERAL_STATIC)]) = 0 and not(./MODIFIERS/FINAL)]"/>
  <message key="matchxpath.match"
           value="Utility classes must be final."/>
</module>

<!-- Forbids empty methods with no explanation -->
<module name="MatchXpath">
  <property name="query"
            value="//METHOD_DEF[./SLIST and count(./SLIST/*) = 1]/SLIST"/>
  <message key="matchxpath.match" value="Add a nested comment explaining why this method is empty."/>
</module>

<!-- Forbid 'test' in method, variable, class, record, and enum names -->
<module name="MatchXpath">
  <property name="query" value="//METHOD_DEF/IDENT[starts-with(@text,'test') or contains(@text,'Test')]"/>
  <message key="matchxpath.match" value="Method name must not contain &quot;test&quot; outside of test source sets."/>
</module>
<module name="MatchXpath">
  <property name="query" value="//VARIABLE_DEF/IDENT[starts-with(@text,'test') or contains(@text,'Test')]"/>
  <message key="matchxpath.match" value="Variable name must not contain &quot;test&quot;."/>
</module>
<module name="MatchXpath">
  <property name="query" value="//CLASS_DEF/IDENT[contains(@text,'Test')]"/>
  <message key="matchxpath.match" value="Class name must not contain &quot;test&quot;."/>
</module>
<module name="MatchXpath">
  <property name="query" value="//RECORD_DEF/IDENT[contains(@text,'Test')]"/>
  <message key="matchxpath.match" value="Record name must not contain &quot;test&quot;."/>
</module>
<module name="MatchXpath">
  <property name="query" value="//ENUM_DEF/IDENT[contains(@text,'Test')]"/>
  <message key="matchxpath.match" value="Enum name must not contain &quot;test&quot;."/>
</module>