UUID not working as GeneratedValue Id with merge

[tkburroughs]

Describe the bug

Jakarta Persistence 3.1 added the ability to have a UUID be the id and to also be generated. In some cases such as the following, where strategy = GenerationType.UUID or strategy is omitted (defaulting to AUTO), an IllegalArgumentException is being raised when trying to save an entity for the first time (when it starts out without an id, needing it generated).

    @GeneratedValue(strategy = GenerationType.UUID)
    @Id
    public UUID id;

java.lang.IllegalArgumentException: Source object is not an instance of java.util.UUID
	at org.eclipse.persistence.mappings.converters.UUIDConverter.convertObjectValueToDataValue(UUIDConverter.java:46)
	at org.eclipse.persistence.mappings.foundation.AbstractDirectMapping.getFieldValue(AbstractDirectMapping.java:790)
	at org.eclipse.persistence.mappings.foundation.AbstractDirectMapping.valueFromObject(AbstractDirectMapping.java:1202)
	at org.eclipse.persistence.internal.descriptors.ObjectBuilder.extractPrimaryKeyFromObject(ObjectBuilder.java:3156)
	at org.eclipse.persistence.internal.sessions.MergeManager.registerObjectForMergeCloneIntoWorkingCopy(MergeManager.java:1062)
	at org.eclipse.persistence.internal.sessions.MergeManager.mergeChangesOfCloneIntoWorkingCopy(MergeManager.java:575)
	at org.eclipse.persistence.internal.sessions.MergeManager.mergeChanges(MergeManager.java:324)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.mergeCloneWithReferences(UnitOfWorkImpl.java:3641)
	at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.mergeCloneWithReferences(RepeatableWriteUnitOfWork.java:402)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.mergeCloneWithReferences(UnitOfWorkImpl.java:3601)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.mergeInternal(EntityManagerImpl.java:644)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.merge(EntityManagerImpl.java:622)

To Reproduce
Steps/resources to reproduce the behavior:

Update the following EclipseLink test:

• TestUUIDGenerator.testBasicUUIDIdentity_AUTO_Generator()

Change the call to persist to merge.

Expected behavior
The merge should be successful.

Basically the same behavior as seen with other generated types (i.e., SEQUENCE).

[tkburroughs]

@rfelcman Thanks for addressing this issue so quickly!

Out of curiosity, did you not update convertDataValueToObjectValue to also tolerate null because null values would not be supported for UUID in the database?

[rfelcman]

@rfelcman Thanks for addressing this issue so quickly!

Out of curiosity, did you not update convertDataValueToObjectValue to also tolerate null because null values would not be supported for UUID in the database?

It's about similar pattern like some other convertDataValueToObjectValue implementations. It's about org.eclipse.persistence.internal.sessions.UnitOfWorkImpl#assignSequenceNumber(java.lang.Object, org.eclipse.persistence.descriptors.ClassDescriptor) and org.eclipse.persistence.internal.descriptors.ObjectBuilder#assignSequenceNumber(java.lang.Object, java.lang.Object, org.eclipse.persistence.internal.sessions.AbstractSession, org.eclipse.persistence.queries.WriteObjectQuery) calls.