Projection results in mapping exception if entity has non nullable fields kotlin

[alirestum]

If the enitity is a Kotlin data class with non nullable values the projection fails.

The following minimal project reproduces the error:

@Node("SomeEntity")
data class SomeEntity(
	@Id
	val id: String = UUID.randomUUID().toString(),
	val propertyOne: String,
	val propertyTwo: String
)

interface Projection {
	val propertyOne: String
}

@Repository
interface SomeEntityRepository : Neo4jRepository<SomeEntity, String> {
	fun findAllProjectedBy(): List<Projection>
}

@SpringBootApplication
class DemoApplication(
	private val someEntityRepository: SomeEntityRepository
) : CommandLineRunner {
	override fun run(vararg args: String?) {
		someEntityRepository.save(SomeEntity(propertyOne = "one", propertyTwo = "two"))
		val result = someEntityRepository.findAllProjectedBy()
	}

}

fun main(args: Array<String>) {
	runApplication<DemoApplication>(*args)
}

Error
org.springframework.data.mapping.MappingException: Error mapping Record<{someEntity: {propertyOne: "one", __elementId__: 11019, __nodeLabels__: ["SomeEntity"]}}>

Caused by: org.springframework.data.mapping.model.MappingInstantiationException: Failed to instantiate com.example.demo.SomeEntity using constructor fun (kotlin.String, kotlin.String, kotlin.String): com.example.demo.SomeEntity with arguments null,one,null,1,null

Caused by: java.lang.NullPointerException: Parameter specified as non-null is null: method com.example.demo.SomeEntity.<init>, parameter propertyTwo

Spring Data Neo4j Version: 7.2.5
Neo4J Java Drivder Version: 5.19.0

[michael-simons]

Thanks for the report. This is due to the fact that we rely in some scenarios on the real entity backing the projection. Fix is under way.