Stackoverflow with Immutables custom builder

Expected behavior

I have a value object making use of Immutables, which requires a customized builder class. It's defined like this:

@Value.Immutable
public abstract class ValueObject {
    public abstract String getFoo();
    public abstract Long getId();

    public static class Builder extends ImmutableValueObject.Builder {
       //some additional builder methods here
    }
}

And a POJO entity class like this:

public class ValueEntity {
    private String foo;
    protected Long id;

    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }

    public String getFoo() { return foo; }
    public void setFoo(String foo) { this.foo = foo; }
}

And a simple Mapper definition that maps ValueEntity to ValueObject:

@Mapper
public abstract class Converter {
    public abstract ValueObject convert(ValueEntity valueEntity);
}

Expectation: The mapper implementation ConverterImpl is generated successfully and uses the builder generated by Immutables to create the ValueObject.

Actual behavior

Generating the mapper fails with a StackOverflowError in the annotation processor:

  	at org.mapstruct.ap.spi.ImmutablesBuilderProvider.findBuilderInfoForImmutables(ImmutablesBuilderProvider.java:58)
  	at org.mapstruct.ap.spi.ImmutablesBuilderProvider.findBuilderInfo(ImmutablesBuilderProvider.java:40)
  	at org.mapstruct.ap.spi.DefaultBuilderProvider.findBuilderInfo(DefaultBuilderProvider.java:96)
  	at org.mapstruct.ap.spi.DefaultBuilderProvider.findBuilderInfo(DefaultBuilderProvider.java:185)
  	at org.mapstruct.ap.spi.ImmutablesBuilderProvider.findBuilderInfoForImmutables(ImmutablesBuilderProvider.java:58)
  	at org.mapstruct.ap.spi.ImmutablesBuilderProvider.findBuilderInfo(ImmutablesBuilderProvider.java:40)
  	at org.mapstruct.ap.spi.DefaultBuilderProvider.findBuilderInfo(DefaultBuilderProvider.java:96)

Steps to reproduce the problem

Clone https://github.com/creckord/mapstruct-immutables-mcve and run ./gradlew clean classes

MapStruct Version

1.5.5

The mapper is created just fine as soon as I remove the inner Builder class, no matter its content.

Also note that specifying the mapping method as

    public abstract ImmutableValueObject.Builder convert(ValueEntity valueEntity);

works.

Specifying it like this

    public abstract ValueObject.Builder convert(ValueEntity valueEntity);

makes the compiler give up with strange compile errors:

error: incompatible types: de.postadress.ars.ImmutableValueObject.Builder cannot be converted to de.postadress.ars.ValueObject.Builder
      if (!(this instanceof ValueObject.Builder)) {

Thanks for the repo @creckord. The problem is the fact that we are always trying to determine the ImmutableXXX.Builder type. Seems like that Immutables has added support for defining a custom builder within the immutable type itself. This means that we need to improve our support for this.

I'll put this as up for grabs in case someone from the community is interested in helping us out with this.

@filiphr Have raised an MR for the fix of this issue please check and let me know. Also I am not able to see or trigger checks tests ran fine on my local.

@Srimathi-S what is failing is the breaking of the API. If you do mvn clean install you should be able to see the errors as well. They are not test errors

Thanks able to see them on local as well now.