I’m spending a lot (read: “waaay to many”) time learning GraphQL. One of the things I had to figure out was how to use nullable types inside my GraphQL schema.
By default when you use a nullable type inside your GraphQL schema, you get the following error message:
ArgumentOutOfRangeException: Explicitly nullable type: Nullable<DateTime> cannot be coerced to a non nullable GraphQL type.
To fix this, you have to expliclity specify the field as nullable in you GraphQL type definition: