pass micro errors from grpc server to grpc client (#1167)

* pass micro errors from grpc server to grpc client

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* wrap micro errors.Error to grpc status

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

error.go

@@ -12,17 +12,21 @@ func microError(err error) error {
 		return nil
 	}
 
-	// micro error
-	if v, ok := err.(*errors.Error); ok {
-		return v
+	if verr, ok := err.(*errors.Error); ok {
+		return verr
 	}
 
 	// grpc error
 	if s, ok := status.FromError(err); ok {
-		if e := errors.Parse(s.Message()); e.Code > 0 {
-			return e // actually a micro error
+		details := s.Details()
+		if len(details) == 0 {
+			if e := errors.Parse(s.Message()); e.Code > 0 {
+				return e // actually a micro error
+			}
+			return errors.InternalServerError("go.micro.client", s.Message())
 		}
-		return errors.InternalServerError("go.micro.client", s.Message())
+		// return first error from details
+		return details[0].(error)
 	}
 
 	// do nothing