selectNew with a long field mapping

[helpermethod]

Hi!

First of all, great project! I've just migrated a project from QueryDSL to Blaze Persistence and it was smooth as butter!

Now, while the migration went smoothly, there was still some weird bug(?):

criteriaBuilderFactory
    .create(entityManager, Tuple::class.java)
    .selectNew(ConversionGroup::class.java)
        .with("conversionEvent")
        .with("conversionType")
        .with("count(distinct profilePersonalizationId)")
    .end()
    // ... more stuff, doing a group by by conversionEvent, conversionType etc.

ConversionGroup is defined as follows

data class ConversionGroup(
    /**
     *  A, B, C or D
     */
    val conversionEvent: String,
    val conversionType: String,
    val count: Long,
)

When I run the query I'm getting

java.lang.RuntimeException: No matching constructor

The problem is, that val count: Long is basically the same as long count in Java, i.e. non-nullable, and Blaze Persistance checks in ClassObjectBuilder.java if the Long value is assignable from the long value:

    // ClassObjectBuilder.java Line 48 
    if (tuple[i] != null && !paramTypes[i].isAssignableFrom(tuple[i].getClass())) {

If I change val count: Long to val count: Long? it works, because now it's the same as Long count in Java.

Is there some way to work around this behaviour, or do I need to use Long? I suspect the problem is the same in Java if I try to map to a long field.

[helpermethod]

I suspect the method ClassObjectBuilder.getConstructor needs to also take primitive types into account. I guess I could create a PR for this.

[beikov]

This would be nice, though I would recommend you to look into Entity-Views instead for modelling this :)

[helpermethod]

Yes, Entity-Views would certainly be better, but this is a low-effort migration to get rid of Query DSL, and for that we didn't want to rewrite too much. But it was actually very easy to migrate the Query DSL Queries to Blaze Persistence :).