Map java.util.UUID to ID instead of String

[mriceron]

The scope of the PR is to map java.util.UUID to ID instead of String.

I'm not sure which is the best place to add a test for this since I just took a quick look at the project, I'm open to suggestions.

[ghostdogpr]

Awesome!

There was a test in ExecutionSpec and it still passes since the result is the same as before. If you want to check the returned type explicitly, you could add one here: https://github.com/ghostdogpr/caliban/blob/master/core/src/test/scala/caliban/schema/SchemaSpec.scala

[ghostdogpr]

Thanks! I’ll merge it tomorrow before releasing a new version.

[mriceron]

Thanks to you for the library and the support! Looking forward to the release :D