Lombok annotation processor not added to modules of a Maven multi-module project

What version of OpenRewrite are you using?

• OpenRewrite v8.83.0
• Maven plugin v6.40.0
• rewrite-migrate-java v3.35.0

How are you running OpenRewrite?

via Maven on a multi-module project

What is the smallest, simplest way to reproduce the problem?

This is a multi-module project with a root and two modules. One of the modules uses lombok.
I set the version of rewrite-migrate-java to 3.31.2 because the behaviour changed from 3.31.1 to 3.31.2 and is the same from 3.31.2 to 3.35.0.

pom.xml of root module:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>my-app</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>pom</packaging>
  <modules>
    <module>with-lombok</module>
    <module>without-lombok</module>
  </modules>

  <properties>
    <maven.compiler.release>21</maven.compiler.release>
  </properties>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.44</version>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>6.40.0</version>
        <configuration>
          <exportDatatables>true</exportDatatables>
          <activeRecipes>
            <recipe>org.openrewrite.java.migrate.EnableLombokAnnotationProcessor</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-migrate-java</artifactId>
            <version>3.31.2</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

pom.xml of module with-lombok:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.example</groupId>
    <artifactId>my-app</artifactId>
    <version>1.0-SNAPSHOT</version>
  </parent>

  <artifactId>with-lombok</artifactId>

  <dependencies>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
    </dependency>
  </dependencies>
</project>

pom.xml of module without-lombok:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.example</groupId>
    <artifactId>my-app</artifactId>
    <version>1.0-SNAPSHOT</version>
  </parent>

  <artifactId>without-lombok</artifactId>

</project>

What did you expect to see?

Up to rewrite-migrate-java version 3.31.1, the Lombok annotation processor was added to the parent pom. My understanding is that the intention of #1031 (added in version 3.31.2) was to add the annotation processor only to those modules where lombok is used.

Therefore, I expect

• the pom.xml of the root module to be unchanged,
• the pom.xml of module without-lombok to be unchanged and
• the annotation processor being added to the pom.xml of module with-lombok:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <parent>
   <groupId>org.example</groupId>
   <artifactId>my-app</artifactId>
   <version>1.0-SNAPSHOT</version>
 </parent>

 <artifactId>with-lombok</artifactId>

 <dependencies>
   <dependency>
     <groupId>org.projectlombok</groupId>
     <artifactId>lombok</artifactId>
   </dependency>
 </dependencies>
 <build>
   <plugins>
     <plugin>
       <groupId>org.apache.maven.plugins</groupId>
       <artifactId>maven-compiler-plugin</artifactId>
       <configuration>
         <annotationProcessorPaths>
           <path>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
             <version>1.18.44</version>
           </path>
         </annotationProcessorPaths>
       </configuration>
     </plugin>
   </plugins>
 </build>
</project>

What did you see instead?

The Lombok annotation processor is added to none of the pom.xml files.

Additional considerations

• The Lombok annotation processor will be added, when I run rewrite:run directly on the module with-lombok. But I doubt that it is the intended behaviour to run the target on each module individually.
• The tests added with #1031 do not truly use a multi-module project. The new test doesNotAddLombokToModuleWithoutLombok just uses a set of two (unrelated) modules.
• Is traversing the module hierarchy the missing part?

Start with the EnableLombokAnnotationProcessor recipe and the test named doesNotAddLombokToModuleWithoutLombok, then reproduce rewrite:run at the multi-module root and directly in with-lombok. Compare this behavior with the tests added in #1031. Done means the root and without-lombok POMs remain unchanged while the annotation processor is added to with-lombok.