Gradle Plugin/Openrewrite should skip files anntoated with javax.annotation.Generated

[blipper]

What problem are you trying to solve?

Avoiding updating generated java files. e.g. Those generated by XJC

Describe the solution you'd like

Skip classes/files annotated with https://docs.oracle.com/en/java/javase/17/docs/api/java.compiler/javax/annotation/processing/Generated.html

https://docs.oracle.com/javase/8/docs/technotes/tools/unix/xjc.html

Have you considered any alternatives or workarounds?

Directory skipping but this is build dependent and prone to additional issues.

Additional context

Are you interested in [contributing this feature to OpenRewrite]

Yes

[timtebeek]

Hi! Thanks for the suggestion and offer to help. As a bit of context let me link you to how for instance the Maven plugin handles generated sources, as that might factor in here as well: https://github.com/openrewrite/rewrite-maven-plugin/blob/09fe6c413311aba7ae160bd4e6e8b38f1d41bad6/src/main/java/org/openrewrite/maven/MavenMojoProjectParser.java#L428-L433

You'll notice that generated sources get a org.openrewrite.marker.Generated marker attached to them, which then later excludes them from showing changes: https://github.com/openrewrite/rewrite/blob/c3270d00822efef1f4a0bc175ac417ffea8d9c8a/rewrite-core/src/main/java/org/openrewrite/scheduling/RecipeRunCycle.java#L172-L176

https://github.com/openrewrite/rewrite/blob/c3270d00822efef1f4a0bc175ac417ffea8d9c8a/rewrite-core/src/main/java/org/openrewrite/internal/InMemoryLargeSourceSet.java#L111-L113

It appears we don't yet take javax.annotation.Generated into account, but I could see a point being made to also add our internal generated marker to classes annotated as generated. Would you want to help explore that option?

[blipper]

That seems pretty straightforward. I assume you would want to use reflection to test or are you okay taking a dependency on the generated class directly?

[timtebeek]

Great to hear; elsewhere we use FindAnnotations.find to find annotations on LST elements, with those dependencies only necessary on the projects themselves, not for the recipe development.

https://github.com/openrewrite/rewrite/blob/c3270d00822efef1f4a0bc175ac417ffea8d9c8a/rewrite-java/src/main/java/org/openrewrite/java/ExtractInterface.java#L135