Apply type system directives in macro based schemas

.formatter.exs

@@ -8,6 +8,8 @@ locals_without_parens = [
   config: 1,
   deprecate: 1,
   description: 1,
+  directive: 1,
+  directive: 2,
   directive: 3,
   enum: 2,
   enum: 3,

lib/absinthe/blueprint/input/value.ex

@@ -38,4 +38,14 @@ defmodule Absinthe.Blueprint.Input.Value do
   def valid?(%{normalized: %Absinthe.Blueprint.Input.Null{}}), do: true
   def valid?(%{normalized: nil}), do: false
   def valid?(%{normalized: _}), do: true
+
+  def build(value) do
+    %Absinthe.Blueprint.Input.Value{
+      data: value,
+      normalized: nil,
+      raw: %Absinthe.Blueprint.Input.RawValue{
+        content: Absinthe.Blueprint.Input.parse(value)
+      }
+    }
+  end
 end

lib/absinthe/blueprint/schema.ex

@@ -129,6 +129,11 @@ defmodule Absinthe.Blueprint.Schema do
     build_types(rest, [field | stack], buff)
   end
 
+  defp build_types([{:directive, trigger} | rest], [field | stack], buff) do
+    field = Map.update!(field, :directives, &[trigger | &1])
+    build_types(rest, [field | stack], buff)
+  end
+
   defp build_types([{:trigger, trigger} | rest], [field | stack], buff) do
     field = Map.update!(field, :triggers, &[trigger | &1])
     build_types(rest, [field | stack], buff)

lib/absinthe/middleware.ex

@@ -310,6 +310,9 @@ defmodule Absinthe.Middleware do
       [{:ref, Absinthe.Type.BuiltIns.Introspection, _}] ->
         expanded
 
+      [{:ref, Absinthe.Phase.Schema.DeprecatedDirectiveFields, _}] ->
+        expanded
+
       _ ->
         schema.middleware(expanded, field, object)
     end

lib/absinthe/phase/schema/deprecated_directive_fields.ex

@@ -0,0 +1,58 @@
+defmodule Absinthe.Phase.Schema.DeprecatedDirectiveFields do
+  @moduledoc false
+  # The spec of Oct 2015 has the onOperation, onFragment and onField
+  # fields for directives (https://spec.graphql.org/October2015/#sec-Schema-Introspection)
+  # See https://github.com/graphql/graphql-spec/pull/152 for the rationale.
+  # These fields are deprecated and can be removed in the future.
+  alias Absinthe.Blueprint
+
+  use Absinthe.Schema.Notation
+
+  @behaviour Absinthe.Phase
+
+  def run(input, _options \\ []) do
+    blueprint = Blueprint.prewalk(input, &handle_node/1)
+
+    {:ok, blueprint}
+  end
+
+  defp handle_node(%Blueprint.Schema.ObjectTypeDefinition{identifier: :__directive} = node) do
+    [types] = __MODULE__.__absinthe_blueprint__().schema_definitions
+
+    new_node = Enum.find(types.type_definitions, &(&1.identifier == :deprecated_directive_fields))
+
+    fields = node.fields ++ new_node.fields
+
+    %{node | fields: fields}
+  end
+
+  defp handle_node(node) do
+    node
+  end
+
+  object :deprecated_directive_fields do
+    field :on_operation, :boolean do
+      deprecate "Check `locations` field for enum value OPERATION"
+
+      resolve fn _, %{source: source} ->
+        {:ok, Enum.any?(source.locations, &Enum.member?([:query, :mutation, :subscription], &1))}
+      end
+    end
+
+    field :on_fragment, :boolean do
+      deprecate "Check `locations` field for enum value FRAGMENT_SPREAD"
+
+      resolve fn _, %{source: source} ->
+        {:ok, Enum.member?(source.locations, :fragment_spread)}
+      end
+    end
+
+    field :on_field, :boolean do
+      deprecate "Check `locations` field for enum value FIELD"
+
+      resolve fn _, %{source: source} ->
+        {:ok, Enum.member?(source.locations, :field)}
+      end
+    end
+  end
+end

lib/absinthe/pipeline.ex

@@ -124,6 +124,7 @@ defmodule Absinthe.Pipeline do
 
     [
       Phase.Schema.TypeImports,
+      Phase.Schema.DeprecatedDirectiveFields,
       Phase.Schema.ApplyDeclaration,
       Phase.Schema.Introspection,
       {Phase.Schema.Hydrate, options},