Merge pull request #144 from maoueh/fix/default-root-operation-types

Fix ast.Schema inferred root types on Mutation & Subscription and `shema` definition

validator/schema.go

@@ -134,16 +134,21 @@ func ValidateSchemaDocument(ast *SchemaDocument) (*Schema, *gqlerror.Error) {
 		}
 	}
 
-	if schema.Query == nil && schema.Types["Query"] != nil {
-		schema.Query = schema.Types["Query"]
-	}
+	// Inferred root operation type names should be performed only when a `schema` directive is
+	// **not** provided, when it is, `Mutation` and `Subscription` becomes valid types and are not
+	// assigned as a root operation on the schema.
+	if len(ast.Schema) == 0 {
+		if schema.Query == nil && schema.Types["Query"] != nil {
+			schema.Query = schema.Types["Query"]
+		}
 
-	if schema.Mutation == nil && schema.Types["Mutation"] != nil {
-		schema.Mutation = schema.Types["Mutation"]
-	}
+		if schema.Mutation == nil && schema.Types["Mutation"] != nil {
+			schema.Mutation = schema.Types["Mutation"]
+		}
 
-	if schema.Subscription == nil && schema.Types["Subscription"] != nil {
-		schema.Subscription = schema.Types["Subscription"]
+		if schema.Subscription == nil && schema.Types["Subscription"] != nil {
+			schema.Subscription = schema.Types["Subscription"]
+		}
 	}
 
 	if schema.Query != nil {

validator/schema_test.go

@@ -44,6 +44,19 @@ func TestLoadSchema(t *testing.T) {
 		require.Equal(t, "SearchResult", implements[1].Name) // union
 	})
 
+	t.Run("default root operation type names", func(t *testing.T) {
+		file, err := ioutil.ReadFile("testdata/default_root_operation_type_names.graphql")
+		require.Nil(t, err)
+		s, err := LoadSchema(Prelude, &ast.Source{Input: string(file), Name: "TestLoadSchema"})
+		require.Nil(t, err)
+
+		require.Nil(t, s.Mutation)
+		require.Nil(t, s.Subscription)
+
+		require.Equal(t, "Mutation", s.Types["Mutation"].Name)
+		require.Equal(t, "Subscription", s.Types["Subscription"].Name)
+	})
+
 	t.Run("type extensions", func(t *testing.T) {
 		file, err := ioutil.ReadFile("testdata/extensions.graphql")
 		require.Nil(t, err)

validator/testdata/default_root_operation_type_names.graphql

@@ -0,0 +1,16 @@
+schema {
+    query: Query
+}
+
+type Query {
+    mutation: Mutation!
+    subscription: Subscription!
+}
+
+type Mutation {
+    name: String!
+}
+
+type Subscription {
+    name: String!
+}