ash_graphql/documentation/how_to/upgrade.md

Upgrading to 1.0

AshGraphql 1.0 is a major release that introduces 3.0 support as well as a few breaking changes for AshGraphql itself.

Automagic atom/union/map types are no more

Pre 1.0: AshGraphql automatically generated types for attributes/arguments that were atom/union/map types, giving them a name like postStatus, for an attribute status on a resource post. While convenient, this incurred significant internal complexity, and had room for strange ambiguity. For example, if you had two actions, that each had an argument called :status, and that :status was an enum with different values, you would get a conflict at compile time due to conflicting type names.

What you'll need to change

AshGraphql will now only generate types for types defined using Ash.Type.NewType or Ash.Type.Enum. For example, if you had:

attribute :post_status, :atom, constraints: [one_of: [:active, :archived]]

in 3.0 this attribute would display as a :string. To fix this, you would define an Ash.Type.Enum:

defmodule MyApp.PostStatus do
  use Ash.Type.Enum, values: [:active, :archived]

  def graphql_type(_), do: :post_status
  def graphql_input_type(_), do: :post_status
end

Then you could use it in your attribute:

attribute :post_status, MyApp.PostStatus

The same goes for map types with the :fields constraint, as well as union types, except you must define those using Ash.Type.NewType. For example:

attribute :scale, :union, constraints: [
  types: [
    whole: [
      type: :integer
    ],
    fractional: [
      type: :decimal
    ]
  ]
]

Here you would get a compile error, indicating that we cannot determine a type for :union. To resolve this, you would define an Ash.Type.NewType, like so:

defmodule MyApp.Scale do
  use Ash.Type.NewType, subtype_of: :union, constraints: [
    types: [
      whole: [
        type: :integer
      ],
      fractional: [
        type: :decimal
      ]
    ]
  ]

  def graphql_type(_), do: :scale
  def graphql_input_type(_), do: :scale
end

Then you could use it in your application like so:

attribute :scale, MyApp.Scale