Fixed #355 handle null pointer lists

executor.go

@@ -727,6 +727,9 @@ func completeLeafValue(returnType Leaf, result interface{}) interface{} {
 // completeListValue complete a list value by completing each item in the list with the inner type
 func completeListValue(eCtx *executionContext, returnType *List, fieldASTs []*ast.Field, info ResolveInfo, path *responsePath, result interface{}) interface{} {
 	resultVal := reflect.ValueOf(result)
+	if resultVal.Kind() == reflect.Ptr {
+		resultVal = resultVal.Elem()
+	}
 	parentTypeName := ""
 	if info.ParentType != nil {
 		parentTypeName = info.ParentType.Name()

lists_test.go

@@ -899,3 +899,17 @@ func TestLists_ValueMayBeNilPointer(t *testing.T) {
 		t.Fatalf("Unexpected result, Diff: %v", testutil.Diff(expected, result))
 	}
 }
+
+func TestLists_NullableListOfInt_ReturnsNull(t *testing.T) {
+	ttype := graphql.NewList(graphql.Int)
+	type dataType *[]int
+	var data dataType
+	expected := &graphql.Result{
+		Data: map[string]interface{}{
+			"nest": map[string]interface{}{
+				"test": nil,
+			},
+		},
+	}
+	checkList(t, ttype, data, expected)
+}

union_interface_test.go

@@ -627,13 +627,8 @@ func TestUnionIntersectionTypes_ValueMayBeNilPointer(t *testing.T) {
 	expected := &graphql.Result{
 		Data: map[string]interface{}{
 			"query": map[string]interface{}{
-				"pet": map[string]interface{}{
-					"__typename": "Cat",
-				},
-				"named": map[string]interface{}{
-					"__typename": "Cat",
-					"name":       nil,
-				},
+				"pet":   nil,
+				"named": nil,
 			}},
 	}
 	result := g(t, graphql.Params{

values.go

@@ -302,6 +302,9 @@ func isNullish(src interface{}) bool {
 	}
 	value := reflect.ValueOf(src)
 	if value.Kind() == reflect.Ptr {
+		if value.IsNil() {
+			return true
+		}
 		value = value.Elem()
 	}
 	switch value.Kind() {
@@ -324,6 +327,9 @@ func isIterable(src interface{}) bool {
 		return false
 	}
 	t := reflect.TypeOf(src)
+	if t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
 	return t.Kind() == reflect.Slice || t.Kind() == reflect.Array
 }