/**
  * @param string $fileName
  * @return string
  */
 public function generate(string $fileName) : string
 {
     if (trim($fileName) === '') {
         throw PathGenerationException::emptyFileName();
     }
     return $this->documentUploadDir . $this->pathGenerator->generatePathFromName($fileName);
 }
 public function it_should_throw_an_exception_if_filename_is_an_empty_string()
 {
     //given
     $fileName = '';
     //then
     $this->shouldThrow(PathGenerationException::emptyFileName())->during('generate', [$fileName]);
 }