Validates input nodes against constraints defined by the constraints directive in your Absinthe schema. Constraints can be applied to fields and arguments, enforcing rules such as min, max, etc. These constraints can be applied to both individual items and lists simultaneously.

Example usage

Add this phase to your pipeline in your router:

pipeline =
  config
  |> Absinthe.Plug.default_pipeline(opts)
  |> AbsintheHelpers.Phases.ApplyConstraints.add_to_pipeline(opts)

Add the constraints directive's prototype schema to your schema:

defmodule MyApp.Schema do
  use Absinthe.Schema

  @prototype_schema AbsintheHelpers.Directives.Constraints

  directive :constraints do
    on([:argument_definition, :field_definition, :input_field_definition])

    arg(:min, :integer, description: "Minimum value allowed")
    arg(:max, :integer, description: "Maximum value allowed")
    arg(:min_items, :integer, description: "Minimum number of items allowed in a list")
    arg(:max_items, :integer, description: "Maximum number of items allowed in a list")
  end
  # ...
end

Apply constraints to a field or argument:

field :my_list, list_of(:integer) do
  directive(:constraints, [min_items: 2, max_items: 5, min: 1, max: 100])

  resolve(&MyResolver.resolve/3)
end

field :my_field, :integer do
  arg :my_arg, non_null(:string), directives: [constraints: [min: 10]]

  resolve(&MyResolver.resolve/3)
end