func zipWithBetterErrors(uploadDir string, zipFile *os.File) error {
zipper := app_files.ApplicationZipper{}
zipError := zipper.Zip(uploadDir, zipFile)
switch err := zipError.(type) {
case nil:
return nil
case *errors.EmptyDirError:
zipFile = nil
return zipError
default:
return fmt.Errorf("%s: %s", "Error zipping application", err.Error())
}
}
