Translate existing refactoring rules from Jackpot

[jglick]

Jenkins core already contains some Jackpot-based rules in the META-INF/upgrade pseudo-package. These are offered automatically to plugin developers using the NetBeans IDE. It would be better to delete that and create analogous rules in this repo that anyone could use.

[timtebeek]

Thanks for chiming in here @jglick !

Refaster recipes

I've had a quick look at the .hint files in Jenkins, and it appears to me like quite a few of those would be a candidate for our simplified recipe definitions using the Refaster annotations. See for example UseStringIsEmpty.java:

import com.google.errorprone.refaster.annotation.AfterTemplate;
import com.google.errorprone.refaster.annotation.BeforeTemplate;

public class UseStringIsEmpty {
    @BeforeTemplate
    boolean before(String s) {
        return s.length() > 0;
    }

    @AfterTemplate
    boolean after(String s) {
        return !s.isEmpty();
    }
}

We allow you to write tests for such recipes as well, as seen in UseStringIsEmptyTest.java

    @Test
    void lengthGreaterZero() {
        rewriteRun(
          java( // before
            """
              class Test {
                  void m(String s) {
                      boolean b = s.length() > 0;
                  }
              }
              """, // after
            """
              class Test {
                  void m(String s) {
                      boolean b = !s.isEmpty();
                  }
              }
              """
          )
        );
    }

I don't think it requires a lot of creativity to see how that could serve to similarly convert for instance the use of printStackTrace in META-INF/upgrade/Functions.hint

Declarative recipes

Other simpler one to one replacements can be achieved with a declarative yaml recipe only, such that you can achieve these replacements with three lines of yaml; for instance for META-INF/upgrade/JSR-305.hint

javax.annotation.CheckForNull => edu.umd.cs.findbugs.annotations.CheckForNull;;
javax.annotation.Nonnull => edu.umd.cs.findbugs.annotations.NonNull;;
javax.annotation.Nullable => edu.umd.cs.findbugs.annotations.Nullable;;

In this case, the change type recipe is likely what you need.

type: specs.openrewrite.org/v1beta/recipe
name: com.yourorg.ChangeTypeExample
displayName: Change type example
recipeList:
  - org.openrewrite.java.ChangeType:
      oldFullyQualifiedTypeName: javax.annotation.CheckForNull
      newFullyQualifiedTypeName: edu.umd.cs.findbugs.annotations.CheckForNull
  - org.openrewrite.java.ChangeType:
      oldFullyQualifiedTypeName: javax.annotation.Nonnull
      newFullyQualifiedTypeName: edu.umd.cs.findbugs.annotations.NonNull
  - org.openrewrite.java.ChangeType:
      oldFullyQualifiedTypeName: javax.annotation.Nullable
      newFullyQualifiedTypeName: edu.umd.cs.findbugs.annotations.Nullable

Hope that helps get you started! If you have any questions feel free to chime in here or on our public Slack.

[sghill]

I had not seen refaster recipes before - this is great!

Wanted to quickly note that the JSR-305 hint is implemented as org.openrewrite.jenkins.JavaxAnnotationsToSpotbugs with tests.