Update to the June 2018 GraphQL spec

[LegNeato]

A new spec is out (https://github.com/facebook/graphql/releases/tag/June2018). It looks like a lot of our error handling questions / behaviors have been clarified among other things.

[theduke]

We should come up with a checklist of what we have to implement and have issues for everything.

[LegNeato]

#219 switched from data to extensions for custom error data.

[dvic]

@LegNeato I think it would be useful to have a test suite based on https://github.com/graphql-cats/graphql-cats. That project seems to cover many scenario's, I think also beyond the June 2018 spec, but at least then we have an idea of what is supported and what is not.

I'm not sure what the implementation would be exactly (a simple dynamic schema executor based on the scenarios'?) but the project is useful at least as a point of reference :)

[theduke]

@dvic I already made an issue for this a while ago.

#245

[dvic]

@LegNeato Ah nice, next time I'll make sure to do a search ;) Maybe I have this weekend time to have a look at it to see what we can do with it.

[tyranron]

@LegNeato I guess this has been fixed in #631?

[LegNeato]

Yes, this should be fixed.