I have downloaded the latest checkstyle from: https://checkstyle.org/cmdline.html#Download_and_Run
I have executed the cli and showed it below, as cli describes the problem better than 1,000 words
/var/tmp $ javac Test.java
/var/tmp $ cat config.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
"http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
<module name="Checker">
<property name="severity" value="warning"/>
<property name="charset" value="UTF-8"/>
<property name="fileExtensions" value="java, properties, xml"/>
<module name="Checker">
<module name="TreeWalker">
<module name="PatternVariableAssignment"/>
</module>
</module>
</module>/var/tmp $ cat Test.java
public class Test {
public static boolean testMethod(Object s) {
if (!(s instanceof String r)) {
return false;
}
r = null;
return true;
}
}/var/tmp $ RUN_LOCALE="-Duser.language=en -Duser.country=US"
/var/tmp $ java $RUN_LOCALE -jar checkstyle-10.25.1-SNAPSHOT.jar -c config.xml Test.java
Starting audit...
Audit done.
Expected: PatternVariableAssignment mark r=null line as violation since pattern variable r is being assigned
The scope of a pattern variable can extend beyond the statement that introduced it:
From https://docs.oracle.com/en/java/javase/18/language/pattern-matching-instanceof-operator.html
.
I have downloaded the latest checkstyle from: https://checkstyle.org/cmdline.html#Download_and_Run
I have executed the cli and showed it below, as cli describes the problem better than 1,000 words
/var/tmp $ cat Test.java public class Test { public static boolean testMethod(Object s) { if (!(s instanceof String r)) { return false; } r = null; return true; } }Expected: PatternVariableAssignment mark
r=nullline as violation since pattern variableris being assignedThe scope of a pattern variable can extend beyond the statement that introduced it:From https://docs.oracle.com/en/java/javase/18/language/pattern-matching-instanceof-operator.html
.