Making sure the input data for resolvers is consistent about graphql-js HOT 3 CLOSED

Great question. This is something I would say is currently not easy to do in the JS reference impl but probably should be. I'll leave this open to track it.

In our PHP implementation in production at Facebook, we have a function that each type defines that simply checks to ensure the produced value correctly fits the type expected (returns boolean), so that resolver functions for the sub-fields can be written with more confidence.

from graphql-js.

So would a potential solution like the Facebook one look something like this?

const Thing = new GraphQLObjectType({
  name: "Thing",
  description: "It's a 3D thing!",
  validate: (it) => (it.width && it.height && it.depth),
  fields: ...
});

from graphql-js.

Yes, graphql-js has a function like this currently called isTypeOf, I just need to wire it up in this way.

from graphql-js.