@VariableName in XPath rule replacement (due to deprecation and removal from PMD 7)

[pnatashap]

I working on update rules to the new version of PMD and faced with deprecation of FieldDeclaration/@variablename. I got the message in log

WARNING: Use of deprecated attribute 'FieldDeclaration/@VariableName' by XPath rule ..., please use VariableDeclaratorId/@Name instead

I have previous rule with

<rule name="AvoidDirectAccessToStaticFields" message="Static fields should be accessed in a static way [CLASS_NAME.FIELD_NAME]." language="java" class="net.sourceforge.pmd.lang.rule.XPathRule">
    <description>
      Avoid accessing static fields directly.
    </description>
    <priority>3</priority>
    <properties>
      <property name="xpath">
        <value><![CDATA[
          //Name[@Image = //FieldDeclaration[@Static='true']/@VariableName]
        ]]></value>
      </property>
    </properties>
    <example>
  <![CDATA[
  public final class DirectAccessToStaticFields {
    private static int num = 1;

    public static int number() {
        return num; // violation
    }
   public static int correct() {
        return DirectAccessToStaticFields.num; // correct
    }
  }
  ]]>
    </example>
  </rule>

And it works fine (but with warning), but I can not rewrite this XPath to work without warnings using the message (or any other way I found).
Can someone help with it?

[oowekyala]

You can try this (didn't test it):

//VariableAccess[@Name = //FieldDeclaration[@Static = true()]/VariableDeclarator/VariableDeclaratorId/@Name]

Keep in mind VariableDeclaratorId has been renamed VariableId in the actual PMD 7 release, which ships later this month.

[pnatashap]

@oowekyala unfortunately this variant doesn't work :(

[oowekyala]

It works on master (modulo the change to VariableId). What version of PMD are you using?

[adangel]

Ok, here is the updated rule for various PMD versions:

PMD 6.55.0 - XPath 1.0:

//Name[@Image = //FieldDeclaration[@Static='true']/VariableDeclarator/VariableDeclaratorId/@Name]

Note: Replaced @VariableName with VariableDeclarator/VariableDeclaratorId/@Name

PMD 6.55.0 - XPath 2.0:

//Name[@Image = //FieldDeclaration[@Static=true()]/VariableDeclarator/VariableDeclaratorId/@Name]

Note: The static attribute is now a real boolean value and not a string anymore.
Note 2: You also need to set <property name="version" value="2.0"/>.
Note 3: This is the prerequisite for update to PMD 7

PMD 7.0.0-rc4:

//VariableAccess[@Name = //FieldDeclaration[@Static=true()]/VariableDeclarator/VariableDeclaratorId/@Name]

Note: You don't need to set <property name="version" value="2.0"/> anymore - PMD 7 uses XPath 3.1 by default and that's the only supported XPath version.
Note 2: AST changed: The node is now called VariableAccess

PMD 7.0.0:

//VariableAccess[@Name = //FieldDeclaration[@Static=true()]/VariableDeclarator/VariableId/@Name]

Note: AST changed again: VariableDeclaratorId -> VariableId

I guess, the deprecation notice here

pmd/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTFieldDeclaration.java

Line 181 in ef34553

@DeprecatedAttribute(replaceWith = "VariableDeclaratorId/@Name")

Could have been more explicit by saying replaceWith = "VariableDeclarator/VariableDeclaratorId/@Name".

Tipp: Use the designer to develop rules: https://docs.pmd-code.org/latest/pmd_userdocs_extending_designer_reference.html

[pnatashap]

Thanks! works with xpath 2.0!