Improve error messages for invalid input types

lib/graphql/schema/traversal.rb

@@ -139,7 +139,7 @@ def visit(schema, member, context_description)
           prev_type = @type_map[type_defn.name]
           # Continue to visit this type if it's the first time we've seen it:
           if prev_type.nil?
-            validate_type(type_defn, context_description)
+            validate_type(type_defn)
             @type_map[type_defn.name] = type_defn
             case type_defn
             when GraphQL::ObjectType
@@ -217,10 +217,10 @@ def visit_field_on_type(schema, type_defn, field_defn, dynamic_field: false)
         GraphQL::Query::Arguments.construct_arguments_class(instrumented_field_defn)
       end
 
-      def validate_type(member, context_description)
-        error_message = GraphQL::Schema::Validation.validate(member)
+      def validate_type(type)
+        error_message = GraphQL::Schema::Validation.validate(type)
         if error_message
-          raise GraphQL::Schema::InvalidTypeError.new("#{context_description} is invalid: #{error_message}")
+          raise GraphQL::Schema::InvalidTypeError.new("#{type.name} is invalid: #{error_message}")
         end
       end
     end

spec/graphql/schema/traversal_spec.rb

@@ -97,6 +97,28 @@ def traversal(types)
     it "raises an InvalidTypeError when passed an object that isnt a GraphQL::BaseType" do
       assert_raises(GraphQL::Schema::InvalidTypeError) {  traversal([another_invalid_type]) }
     end
+
+    it "raises an InvalidTypeError for object field arguments referencing invalid input objects" do
+      other_type = GraphQL::ObjectType.define do
+        name "MyOtherType"
+        field :someField, GraphQL::STRING_TYPE
+      end
+
+      invalid_input_type = GraphQL::InputObjectType.define do
+        name "MyInput"
+        input_field :someField, other_type
+      end
+
+      type = GraphQL::ObjectType.define do
+        name "MyType"
+        field :anotherField, !GraphQL::STRING_TYPE do |field|
+          field.argument :anArgument, invalid_input_type
+        end
+      end
+
+      error = assert_raises(GraphQL::Schema::InvalidTypeError) {  traversal([type]) }
+      assert_equal("MyInput is invalid: argument \"someField\" type must be a valid input type (Scalar or InputObject), not GraphQL::ObjectType (MyOtherType)", error.message)
+    end
   end
 
   describe "when a schema has multiple types with the same name" do