text: import io
  from flask import url_for, request
  from flask import json
  from app.model import Files
  
  
  # test model
  def test_files_db(client):
      assert hasattr(Files, 'id')
      assert hasattr(Files, 'filename')
  
  # test route
  def test_404(client):
      assert client.get('/url-not-exist').status_code == 404
  
  def test_index(client):
      rv = client.get('/')
      assert rv.status_code == 200
      assert "/static/main.css".encode() in rv.data
  
  def test_files_operation(client):
      # upload a file
      client.post(url_for('main.upload_file'), data=dict(
          file=(io.BytesIO(b'hi everybody'), 'name.test')
      ))
      # check if it's uploaded
      rv = client.get('/')
      assert "/file/name.test".encode() in rv.data
      # delete file
      file_id = Files.query.filter_by(filename='name.test').one().id
      client.get(url_for('main.del_file', file_id=file_id))
      # check if it's gone
      rv = client.get('/')
      assert "/file/name.test".encode() not in rv.data
  
  