From f76e50118b8b5dd8989d068db35222bfa0a242d8 Mon Sep 17 00:00:00 2001 From: Cameron Moore Date: Thu, 27 Dec 2018 22:28:54 -0600 Subject: [PATCH] tpl: Provide more detailed errors in Where --- tpl/collections/where.go | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/tpl/collections/where.go b/tpl/collections/where.go index d515d019f..c96c38910 100644 --- a/tpl/collections/where.go +++ b/tpl/collections/where.go @@ -278,18 +278,19 @@ func evaluateSubElem(obj reflect.Value, elemName string) (reflect.Value, error) } mt, ok := objPtr.Type().MethodByName(elemName) if ok { - if mt.PkgPath != "" { + switch { + case mt.PkgPath != "": return zero, fmt.Errorf("%s is an unexported method of type %s", elemName, typ) - } - // struct pointer has one receiver argument and interface doesn't have an argument - if mt.Type.NumIn() > 1 || mt.Type.NumOut() == 0 || mt.Type.NumOut() > 2 { - return zero, fmt.Errorf("%s is a method of type %s but doesn't satisfy requirements", elemName, typ) - } - if mt.Type.NumOut() == 1 && mt.Type.Out(0).Implements(errorType) { - return zero, fmt.Errorf("%s is a method of type %s but doesn't satisfy requirements", elemName, typ) - } - if mt.Type.NumOut() == 2 && !mt.Type.Out(1).Implements(errorType) { - return zero, fmt.Errorf("%s is a method of type %s but doesn't satisfy requirements", elemName, typ) + case mt.Type.NumIn() > 1: + return zero, fmt.Errorf("%s is a method of type %s but requires more than 1 parameter", elemName, typ) + case mt.Type.NumOut() == 0: + return zero, fmt.Errorf("%s is a method of type %s but returns no output", elemName, typ) + case mt.Type.NumOut() > 2: + return zero, fmt.Errorf("%s is a method of type %s but returns more than 2 outputs", elemName, typ) + case mt.Type.NumOut() == 1 && mt.Type.Out(0).Implements(errorType): + return zero, fmt.Errorf("%s is a method of type %s but only returns an error type", elemName, typ) + case mt.Type.NumOut() == 2 && !mt.Type.Out(1).Implements(errorType): + return zero, fmt.Errorf("%s is a method of type %s returning two values but the second value is not an error type", elemName, typ) } res := objPtr.Method(mt.Index).Call([]reflect.Value{}) if len(res) == 2 && !res[1].IsNil() {