Creating an Input Union Type System Directive in Absinthe (opens in new tab)

From Maarten van Vliet: In this post I will explain how to create a type system directive in Absinthe to implement Input Unions in Graphql. The code for this post can be found on Github A common issue with GraphQL is the lack of input unions. This means an input object that lets you choose between a number of potential input types. For example (taken from a spec discussion): input PetInput { cat: CatInput dog: DogInput fish: FishInput } input CatInput { name: String!