Python 单元测试

Question

I have a situation where I need support:

I have a program as logger_1.py which returns a logger class

I have my other program as data_extract.py where I have imported logger_1.py script

---

from logger_1.py import getHLogger

def initl(abc):

    logger.info("Initialise starts")
    newdata = abc + "sometext"
    return newdata

def Main():

      global logger
      logger = getHLogger("dd_12")
      logger.info("Started")

      retu = initl("Hello")

---

Now I have to write a unit test case

import unittest
from data_extract import initl

class data_extract(unittest.TestCase)

      def test_initl(self):
          self.assertEqual(initl("Special"), "Special sometext")

Now when running the test case I am getting logger is not defined.

Please guide how can I mock/patch or ignore logger from my unit test case.

Answer 1

In the testing environment the method Main() is, presumably, never called so the variable logger in method initl is undefined. Mocking variables is a bit more tricky than mocking functions, so first I'd change initl such that the variable logger is always defined and the behaviour can be changed by mocking getHLogger :

from logger_1.py import getHLogger

global logger
logger = getHLogger("dd_12")

def initl(abc):
    logger.info("Initialise starts")
    newdata = abc + "sometext"
    return newdata

def Main():
      logger.info("Started")
      retu = initl("Hello")

Then you can mock getHLogger :

import unittest
from data_extract import initl

class MockLogger()
    def info(msg):
        pass

def mock_get_logger(some_param):
    return MockLogger()

class data_extract(unittest.TestCase)

      @unittest.mock.patch("getHLogger", mock_get_logger)
      def test_initl(self):
          self.assertEqual(initl("Special"), "Special sometext")