[BUG] @SuperBuilder(toBuilder = true) does not call ctor of the base class and does not call the @Builder.ObtainVia

[BorisDaich]

Describe the bug
see the following sample classes . as the result the inherited member of the base class is never initialized

To Reproduce

@SuperBuilder(toBuilder = true)
public abstract class AbstractPropertyChangeSupport implements Serializable {
	@Builder.ObtainVia(method = "createPCS")
	@JsonIgnore
	protected transient PropertyChangeSupport pcs = new PropertyChangeSupport(this);

	protected PropertyChangeSupport createPCS() {
		return new PropertyChangeSupport(this);
	}

	public AbstractPropertyChangeSupport() {
		pcs = new PropertyChangeSupport(this);
	}

	public AbstractPropertyChangeSupport(PropertyChangeSupport pcs) {
		super();
		if (pcs == null)
			pcs = new PropertyChangeSupport(this);
		this.pcs = pcs;
	};

	// this is for the Deserialization ...
	private void readObject(java.io.ObjectInputStream stream) throws IOException, ClassNotFoundException {
		stream.defaultReadObject();
		pcs = new PropertyChangeSupport(this);
	}

}

@SuperBuilder(toBuilder = true)
@Data
@ToString(callSuper = false)
@EqualsAndHashCode(callSuper = false)
@NoArgsConstructor
public class TestDerived extends AbstractPropertyChangeSupport {

	@Builder.Default
	protected String value = "Foo";

	public static void main(String[] args) {
		TestDerived x = TestDerived.builder().build();
		if (x.pcs == null)
			System.err.println("thie PCS is NULL");
		System.out.println(x);
	}

}

Expected behavior
at the point after
TestDerived x = TestDerived.builder().build();
x.pcs should not be null.

Version info (please complete the following information):

• Lombok version 1.18.34
• Platform Java 17 eclipse 2024-09 4.33.0

thank you for the great Tool!!!!

[janrieke]

@SuperBuilder creates its own constructor, which takes a builder instance as its only argument. This constructor copies the values from the given builder to the new instance. However, as the builder has pcs == null, the new instance also receives that null value. So this behavior is expected.

I'm afraid there is no easy solution here. If you need a reference to the instance in construction, you cannot do set in the builder, because there is no such instance, yet. So neither @Builder.Default nor @Builder.ObtainVia plus toBuilder() will work (the latter will compile, but the resulting PropertyChangeSupport instance will have a reference to the old instance, not the new one).

You could manually implement the ctor, but that would take away most of the benefits of lombok in this case: You'd have to implement the copy mechanism by yourself. What you could use is @PostConstructor #1207, but that feature is not finished, yet.

[janrieke]

PS: @Builder.Default could provide a way out at least for @SuperBuilder, because it is only called from the ctor, so the generated init method could also be non-static. However, I remember that we had a discussion about this and we decided to leave it static, but I do not recall the reason and cannot find the discussion here on GitHub.