[BUG] error: wrong number of type arguments; required 3 when using @SuperBuilder and an Annotation applied to the generic type.

[bamapookie]

Describe the bug
I have a parent class that is generic:

@Getter
@SuperBuilder
public class Parent<T extends Comparable<T>> {
  private T value;
}

When I extend it to remove the generic parameter, it works fine:

@SuperBuilder
public class Child extends Parent<Double> {
}

However, when I add an annotation to the generic type, I get the error below:

// ValidDouble.java
@Documented
@Target( { TYPE_USE, ANNOTATION_TYPE })
@Retention(RUNTIME)
public @interface ValidDouble {
}

// ChildWithAnnotation.java
@SuperBuilder // line 5
public class ChildWithAnnotation extends Parent<@ValidDouble Double> {
}

/Users/bamapookie/Repositories/SuperBuilderBug/src/main/java/org/example/superbuilderbug/ChildWithAnnotation.java:5: error: wrong number of type arguments; required 3
@SuperBuilder

Looking at the delombok'ed code and comparing the Child.java and ChildWithAnnotation.java generated files, line 5 contains a significant difference.

// Child.java:5
public static abstract class ChildBuilder<C extends Child, B extends Child.ChildBuilder<C, B>> extends Parent.ParentBuilder<Double, C, B> {
// ChildWithAnnotation.java:5
public static abstract class ChildWithAnnotationBuilder<C extends ChildWithAnnotation, B extends ChildWithAnnotation.ChildWithAnnotationBuilder<C, B>> extends Parent.ParentBuilder<C, B> {

The ChildWithAnnotation.java code is missing the Double generic type parameter for the ParentBuilder, reducing the number of generic type parameters to 2, while the Child.java code does contain the Double generic type parameter.

To Reproduce
Built with a basic gradle build config with the lombok plugin (id("io.freefair.lombok") version "8.4"). All non-lombok imports are in java.lang.annotation.

Expected behavior
Expected ChildWithAnnotation class to build just like Child class.

Version info (please complete the following information):

• Lombok version: 1.18.30
• Platform IntelliJ IDEA 2023.3.2 (Ultimate Edition)
  Build #IU-233.13135.103, built on December 20, 2023
  Licensed to Shawn Kovalchick
  You have a perpetual fallback license for this version.
  Subscription is active until August 20, 2025.
  Runtime version: 17.0.9+7-b1087.9 aarch64
  VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
  macOS 14.2.1
  GC: G1 Young Generation, G1 Old Generation
  Memory: 2048M
  Cores: 10
  Metal Rendering is ON
  Non-Bundled Plugins:
  com.databricks (1.2)
  com.github.copilot (1.4.5.4049)
  org.jetbrains.plugins.rest (233.11799.188)
  CheckStyle-IDEA (5.85.1)
  com.dmarcotte.handlebars (233.11799.172)
  Kotlin: 233.13135.103-IJ

Additional context
I reduced the example to just enough code to illustrate the problem. Code committed to https://github.com/bamapookie/LombokSuperBuilderBug

[janrieke]

Thanks for the detailed bug report. I can reproduce the issue with javac. Eclipse is not affected.
I haven't looked into it, but this seems fixable without too much effort. I'm trying to find some time in the next week.

[janrieke]

This was quite easy to fix. PR is #3594.

[bamapookie]

2 line fix with 242 lines of test code. I aspire to that level of code coverage!

[janrieke]

2 line fix with 242 lines of test code.

Well, TDD is the easiest way to fix such types of bugs:

1. Take the code from the bug report and create a test case from it.
2. See what Lombok makes of it.
3. Change the expected generated code such that it works.
4. Make the test pass, aka fix the bug.

And if you have the test case anyway, you can also commit it.

[bamapookie]

I appreciate the quick response. Any idea when this will make it onto a release?

Thanks.

[rspilker]

This is part of the latest edge release, all feedback is welcome.

[bamapookie]

It's working! Thanks!