Compatibility issue: SchemaException for type with a UUID

[StefanLiebig]

I was switching from com.github.pgutkowski:kgraphql:0.3.0' to 'com.apurebase:kgraphql:0.5.1'.
After that I got the following exception:

Caused by: com.apurebase.kgraphql.schema.SchemaException: An Object type must define one or more fields. Found none on type UUID
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleObjectType(SchemaCompilation.kt:234)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.access$handleObjectType(SchemaCompilation.kt:32)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation$handleRawType$typeCreator$1.invoke(SchemaCompilation.kt:183)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation$handleRawType$typeCreator$1.invoke(SchemaCompilation.kt:32)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleRawType(SchemaCompilation.kt:190)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleSimpleType(SchemaCompilation.kt:161)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handlePossiblyWrappedType(SchemaCompilation.kt:149)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleKotlinProperty(SchemaCompilation.kt:301)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleObjectType(SchemaCompilation.kt:213)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.access$handleObjectType(SchemaCompilation.kt:32)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation$handleRawType$typeCreator$1.invoke(SchemaCompilation.kt:183)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation$handleRawType$typeCreator$1.invoke(SchemaCompilation.kt:32)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleRawType(SchemaCompilation.kt:190)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleSimpleType(SchemaCompilation.kt:161)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleCollectionType(SchemaCompilation.kt:156)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handlePossiblyWrappedType(SchemaCompilation.kt:145)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleOperation(SchemaCompilation.kt:132)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.handleQueries(SchemaCompilation.kt:113)
	at com.apurebase.kgraphql.schema.structure2.SchemaCompilation.perform(SchemaCompilation.kt:56)
	at com.apurebase.kgraphql.schema.dsl.SchemaBuilder.build(SchemaBuilder.kt:26)
	at com.apurebase.kgraphql.KGraphQL$Companion.schema(KGraphQL.kt:8)
	at timebox.graphql.GrapQLKt.<clinit>(GrapQL.kt:21)
	... 40 more

Unfortunatly it does not tell which type is causing the error, but I have just two classes with a UUID property. However, for these classes I have a property resolver that handles the UUID property:

type<TimeEntry> {
     description = "Time entries ..."

     property<String?>("id") {
         resolver { timeEntry ->
             timeEntry.id.toString()
         }
     }
   ...

the timeEntry.id is of type UUID.

Any idea!

[jeggy]

What kotlin type is UUID?

[jeggy]

This works fine for me: https://gist.github.com/jeggy/0b514439a9b2588a28b62433c2da4713

[StefanLiebig]

Sorry, it is java.util.UUID

[jeggy]

I'm not sure how it worked for you before, but I think it would make sense to use scalars here:

stringScalar<UUID> {
   serialize = UUID::toString
   deserialize = UUID::fromString
}

And then just remove the property<String?>("id")

[StefanLiebig]

This is definitely much better and works!
But I do not understand why your fork behaves differently.

[jeggy]

I found the root cause of it 😃

As the error states An Object type must define one or more fields. The UUID has no public fields on it, and after this change, that will report an error: #25

[StefanLiebig]

Ok, that causes the "incompatibility" :-)

However, it would be fine if the error message could name the "Object type", e.g. "The object type java.util.UUID has no ...

[jeggy]

It currently does: An Object type must define one or more fields. Found none on type UUID

Maybe we could re-word it to something like The 'UUID' object type must define atleast one or more fields, so it mentions the object type near the beginning the sentence.

[StefanLiebig]

Damned! I did not remember this. Sorry!

Yes, your proposal sounds good to me.

[jeggy]

Haha, no problem 😄

Always welcome to post more issues here.