Support directives in introspection query

Closes #88

Author: Josh Price

lib/graphql/execution/executor.ex

@@ -98,14 +98,14 @@ defmodule GraphQL.Execution.Executor do
     !resolve_directive(context, directives, :skip)
   end
 
-  defp resolve_directive(context, directives, dir_type) do
-    ast = Enum.find(directives, fn(d) -> d.name.value == Atom.to_string(dir_type) end)
-    directive = apply(GraphQL.Type.Directives, dir_type, [])
+  defp resolve_directive(context, directives, directive_name) do
+    ast = Enum.find(directives, fn(d) -> d.name.value == Atom.to_string(directive_name) end)
+    directive = apply(GraphQL.Type.Directives, directive_name, [])
     if ast do
       %{if: val} = argument_values(directive.args, ast.arguments, context.variable_values)
       val
     else
-      directive.args.if.defaultValue
+      directive_name == :include
     end
   end
 

lib/graphql/type/directive.ex

@@ -2,25 +2,34 @@ defmodule GraphQL.Type.Directive do
   @moduledoc """
   Directives currently supported are @skip and @include
   """
-  defstruct name: "Directive", description: nil, locations: [], args: %{}
+  defstruct name: "Directive",
+            description: nil,
+            locations: [],
+            args: %{},
+            onOperation: false,
+            onFragment: true,
+            onField: true
 end
 
 defmodule GraphQL.Type.Directives do
   alias GraphQL.Type.{Directive, Boolean, NonNull, String}
+  alias GraphQL.Util.Text
 
   def include do
     %Directive{
       name: "include",
-      description: """
-      Directs the executor to include this field or fragment
-      only when the `if` argument is true.
-      """,
+      description:
+        """
+        Directs the executor to include this field or fragment
+        only when the `if` argument is true.
+        """ |> Text.normalize,
       locations: [:Field, :FragmentSpread, :InlineFragment],
       args: %{
         if: %{
           type: %NonNull{ofType: %Boolean{}},
+          name: "if",
           description: "Included when true.",
-          defaultValue: true
+          defaultValue: nil
         }
       }
     }
@@ -29,16 +38,18 @@ defmodule GraphQL.Type.Directives do
   def skip do
     %Directive{
       name: "skip",
-      description: """
-      Directs the executor to skip this field or fragment
-      only when the `if` argument is true.
-      """,
+      description:
+        """
+        Directs the executor to skip this field or fragment
+        when the `if` argument is true.
+        """ |> Text.normalize,
       locations: [:Field, :FragmentSpread, :InlineFragment],
       args: %{
         if: %{
           type: %NonNull{ofType: %Boolean{}},
+          name: "if",
           description: "Skipped when true.",
-          defaultValue: false
+          defaultValue: nil
         }
       }
     }
@@ -47,9 +58,10 @@ defmodule GraphQL.Type.Directives do
   def deprecated do
     %Directive{
       name: "deprecated",
-      description: """
-      Marks an element of a GraphQL schema as no longer supported.
-      """,
+      description:
+        """
+        Marks an element of a GraphQL schema as no longer supported.
+        """,
       locations: [:FieldDefinition, :EnumValue],
       args: %{
         reason: %{

lib/graphql/type/introspection.ex

@@ -57,7 +57,9 @@ defmodule GraphQL.Type.Introspection do
           directives: %{
             description: "A list of all directives supported by this server.",
             type: %NonNull{ofType: %List{ofType: %NonNull{ofType: Directive}}},
-            resolve: nil #schema => schema.getDirectives(),
+            resolve: fn(schema, _, _) ->
+              schema.directives
+            end
           }
         }
       }
@@ -83,7 +85,11 @@ defmodule GraphQL.Type.Introspection do
           description: %{type: %String{}},
           args: %{
             type: %NonNull{ofType: %List{ofType: %NonNull{ofType: InputValue}}},
-            resolve: nil #directive => directive.args || []
+            resolve: fn
+              %{args: args}, _, _ ->
+                Enum.map(args, fn {name, v} -> Map.put(v, :name, name) end)
+              _, _, _ ->  []
+            end
           },
           onOperation: %{type: %NonNull{ofType: %Boolean{}}},
           onFragment: %{type: %NonNull{ofType: %Boolean{}}},
@@ -251,9 +257,9 @@ defmodule GraphQL.Type.Introspection do
           args: %{
             type: %NonNull{ofType: %List{ofType: %NonNull{ofType: InputValue}}},
             resolve: fn
-              (%{args: _args} = schema) ->
-                Enum.map(schema.args, fn({name, v}) -> Map.put(v, :name, name) end)
-              (_) ->  []
+              %{args: args} ->
+                Enum.map(args, fn {name, v} -> Map.put(v, :name, name) end)
+              _ -> []
             end
           },
           type: %{type: %NonNull{ofType: Type}},

lib/graphql/type/schema.ex

@@ -2,7 +2,9 @@ defmodule GraphQL.Schema do
 
   @type t :: %GraphQL.Schema{
     query: Map,
-    mutation: Map
+    mutation: Map,
+    type_cache: Map,
+    directives: [GraphQL.Type.Directive.t]
   }
 
   alias GraphQL.Type.Interface
@@ -12,7 +14,13 @@ defmodule GraphQL.Schema do
   alias GraphQL.Type.CompositeType
   alias GraphQL.Lang.AST.Nodes
 
-  defstruct query: nil, mutation: nil, type_cache: nil
+  defstruct query: nil,
+            mutation: nil,
+            type_cache: nil,
+            directives: [
+              GraphQL.Type.Directives.include,
+              GraphQL.Type.Directives.skip
+            ]
 
   def with_type_cache(schema = %{type_cache: nil}), do: new(schema)
   def with_type_cache(schema), do: schema

test/star_wars/introspection_query_test.exs

@@ -219,7 +219,55 @@ defmodule GraphQL.StarWars.IntrospectionTest do
   test "Can run the full introspection query" do
     {:ok, result} = execute(StarWars.Schema.schema, GraphQL.Type.Introspection.query)
     assert_data(result, %{
-      "__schema" => %{"directives" => nil, "mutationType" => nil, "queryType" => %{"name" => "Query"}, "subscriptionType" => nil,
+      "__schema" => %{"directives" => [
+        %{
+          "name" => "include",
+          "description" => "Directs the executor to include this field or fragment only when the `if` argument is true.",
+          "args" => [
+            %{
+              "name" => "if",
+              "description" => "Included when true.",
+              "type" => %{
+                "kind" => "NON_NULL",
+                "name" => nil,
+                "ofType" => %{
+                  "kind" => "SCALAR",
+                  "name" => "Boolean",
+                  "ofType" => nil
+                }
+              },
+              "defaultValue" => nil
+            }
+          ],
+          "onOperation" => false,
+          "onFragment" => true,
+          "onField" => true
+        },
+        %{
+          "name" => "skip",
+          "description" => "Directs the executor to skip this field or fragment when the `if` argument is true.",
+          "args" => [
+            %{
+              "name" => "if",
+              "description" => "Skipped when true.",
+              "type" => %{
+                "kind" => "NON_NULL",
+                "name" => nil,
+                "ofType" => %{
+                  "kind" => "SCALAR",
+                  "name" => "Boolean",
+                  "ofType" => nil
+                }
+              },
+              "defaultValue" => nil
+            }
+          ],
+          "onOperation" => false,
+          "onFragment" => true,
+          "onField" => true
+        }
+      ],
+      "mutationType" => nil, "queryType" => %{"name" => "Query"}, "subscriptionType" => nil,
       "types" => [%{"description" => "The `Boolean` scalar type represents `true` or `false`.", "enumValues" => nil, "fields" => nil, "inputFields" => nil, "interfaces" => nil, "kind" => "SCALAR", "name" => "Boolean", "possibleTypes" => nil},
        %{"description" => "A character in the Star Wars Trilogy", "enumValues" => nil,
          "fields" => [%{"args" => [], "deprecationReason" => nil, "description" => nil, "isDeprecated" => nil, "name" => "appears_in", "type" => %{"kind" => "LIST", "name" => nil, "ofType" => %{"kind" => "ENUM", "name" => "Episode", "ofType" => nil}}},

test/test_helper.exs

@@ -22,10 +22,7 @@ defmodule ExUnit.TestHelpers do
   end
 
   def assert_data(result, expected) do
-    assert(
-      result[:data] == stringify_keys(expected),
-      message: "Expected result[:data] to equal #{inspect stringify_keys(expected)} but was #{inspect result[:data]}"
-    )
+    assert result[:data] == stringify_keys(expected)
   end
 
   def assert_has_error(result, expected) do