Input unions?

[zth]

Something sorely missing from GraphQL is input unions. While we won't extend the GraphQL language ourselves, we could potentially implement input unions server side:

@gql.inputUnion
type timePeriod = Preset({datePreset: datePreset}) | Dates({from: timestamp, to: timestamp})

@gql.field
let data = (_: query, ~timePeriod) => {
  getDataByTimePeriod(timePeriod)
}

type Query {
  data(datePreset: DatePreset, from: Timestamp, to: Timestamp): DataForPeriod
}

We'd have a code generated layer in each resolver using a input union that automatically throws if the argument configuration isn't correct.

[zth]

Integrated in a slightly different version.