// metoda
public UploadFileResponse uploadFile(@PathVariable String id, @RequestParam("file") MultipartFile file) {
        DbFile dbFile = userService.addFileByUserId(id, file);

        String fileDownloadUri = ServletUriComponentsBuilder.fromCurrentContextPath()
                .path(String.format("%s/%s/files/%s/download", usersRoute, id, dbFile.getId()))
                .toUriString();

        return new UploadFileResponse(dbFile.getFileName(), fileDownloadUri, file.getContentType(), file.getSize());
    }

// test

@Test
   public void givenUser_whenUploadFile_then200StatusAndUploadFileResponse() throws Exception {
        mvc.perform(fileUpload(String.format("%s/%s/files", basePath, user.getId()))
                .file(new MockMultipartFile("test", "test".getBytes())).with(httpBasic("user", "test")))
                .andExpect(status().isOk())
                .andExpect(jsonPath("fileName", is("test")))
                .andExpect(jsonPath("size", is(4L)))
                .andExpect(jsonPath("userId", is(user.getId())));
    }