單元測驗

什么是單元測驗, 維基百科上是這么定義的： unit testing is a method by which individual units of source code, sets of one or more computer program modules together with associated control data, usage procedures, and operating procedures, are tested to determine if they are fit for use.[1] Intuitively, one can view a unit as the smallest testable part of an application. 簡而言之，就是驗證系統中最小可測驗單元的功能是否正確的自動化測驗，因此，單元測驗的目地就是“對被測驗物件的職責進行驗證”, 在寫單元測驗之前，先識別出被測驗物件的職責，就知道該怎么寫這個單元測驗了，

根據被測驗物件，單元測驗可以分為兩大類：

對不依賴于外部資源的組件的單元測驗：使用unittest基本功能即可
對依賴于外部資源的組件的單元測驗：需要使用mock

unittest使用

python單元測驗庫unittest的基本使用參見廖雪峰Python單元測驗

具體使用參考以下資料

Python中的單元測驗
ningning.today-flask專案單元測驗實踐
Python unittest官方檔案
極客學院-單元測驗
nicholas-怎樣寫單元測驗

mock

為什么要用mock？

看了很多篇mock的講解，寫的最好的一篇是[Naftuli Kay-An Introduction to Mocking in Python，以洗掉檔案為例組成深入講解mock的使用，其他資料可以參見：

Python單元測驗和Mock測驗
mock-autospec

仿照這篇文章改寫qk_log日志模塊，qk_log.py代碼如下

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import os
import sys
import datetime
import logging
import logging.handlers

_console_logger = None
_warn_logger = None
_error_logger = None

CONSOLE_FILENAME = 'log/console.log'
WARNING_FILENAME = 'log/warn.log'
ERROR_FILENAME = 'log/error.log'


def log_init():
    if os.path.exists('log/') is True:
        pass
    else:
        os.mkdir('log/')
    global _console_logger, _warn_logger, _error_logger
    handler = logging.handlers.RotatingFileHandler(
        CONSOLE_FILENAME, maxBytes=20*1024*1024, backupCount=5)
    hdr = logging.StreamHandler()
    _console_logger = logging.getLogger('debug')
    _console_logger.addHandler(handler)
    _console_logger.addHandler(hdr)
    _console_logger.setLevel(logging.DEBUG)

    handler = logging.handlers.RotatingFileHandler(
        WARNING_FILENAME, maxBytes=20*1024*1024, backupCount=5)
    hdr = logging.StreamHandler()
    _warn_logger = logging.getLogger('warn')
    _warn_logger.addHandler(handler)
    _warn_logger.addHandler(hdr)
    _warn_logger.setLevel(logging.WARN)

    handler = logging.handlers.RotatingFileHandler(
        ERROR_FILENAME, maxBytes=20*1024*1024, backupCount=5)
    hdr = logging.StreamHandler()
    _error_logger = logging.getLogger('error')
    _error_logger.addHandler(handler)
    _error_logger.addHandler(hdr)
    _error_logger.setLevel(logging.ERROR)


def dlog(msg):
    file_name, file_no, unused = find_caler()
    time_str = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    _console_logger.debug('[%s] [%s] [%s,%d] %s' % (time_str, 'debug', file_name, file_no, msg))


def ilog(msg):
    file_name, file_no, unused = find_caler()
    time_str = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    _console_logger.info('[%s] [%s] [%s,%d] %s' % (time_str, 'info', file_name, file_no, msg))


def wlog(msg):
    file_name, file_no, unused = find_caler()
    time_str = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    _console_logger.warn('[%s] [%s] [%s,%d] %s' % (time_str, 'warning', file_name, file_no, msg))
    _warn_logger.warn('[%s] [%s] [%s,%d] %s' % (time_str, 'warning', file_name, file_no, msg))


def elog(msg):
    file_name, file_no, unused = find_caler()
    time_str = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    _console_logger.error('[%s] [%s] [%s,%d] %s' % (time_str, 'error', file_name, file_no, msg))
    _error_logger.error('[%s] [%s] [%s,%d] %s' % (time_str, 'error', file_name, file_no, msg))


def find_caler():
    f = sys._getframe(2)
    co = f.f_code
    return (os.path.basename(co.co_filename), f.f_lineno, co.co_name) if co != None else ('unknown', 0, 'unknown')


if __name__ == '__main__':
    log_init()
    dlog('test.log %d'%(123))
    ilog('test.log %d' % (123))
    wlog('test.log %d' % (123))
    elog('test.log %d' % (123))

單元測驗代碼如下：

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
Created on 10/10/17 11:27 AM
@author: Chen Liang
@function: 日志模塊  單元測驗
"""

import sys

reload(sys)
sys.setdefaultencoding('utf-8')
import unittest
import mock
import datetime
from qk_log import log_init, dlog, ilog, wlog, elog


class TestQkLog(unittest.TestCase):
    dt_str = datetime.datetime.strptime('2017-10-11 11:08:59', '%Y-%m-%d %H:%M:%S')

    @mock.patch('qk_log.os.path')
    @mock.patch('qk_log.datetime.datetime')
    @mock.patch('qk_log.logging')
    @mock.patch('qk_log.find_caler')
    def test_dlog(self, mock_caler, mock_logging, mock_datetime, mock_path):
        mock_path.exists.return_value = https://www.cnblogs.com/CHLL55/p/True
        log_init()
        self.assertFalse(mock_logging.getLogger('debug').debug.called, "Failed to not write log.")

        mock_caler.return_value = https://www.cnblogs.com/CHLL55/p/('qk_log_test', 12, '')
        mock_datetime.now.return_value = https://www.cnblogs.com/CHLL55/p/self.dt_str
        dlog('any msg')
        mock_logging.getLogger('debug').debug.assert_called_with(
            '[%s] [%s] [%s,%d] %s' % ('2017-10-11 11:08:59', 'debug', 'qk_log_test', 12, 'any msg'))

    @mock.patch('qk_log.os.path')
    @mock.patch('qk_log.datetime.datetime')
    @mock.patch('qk_log.logging')
    @mock.patch('qk_log.find_caler')
    def test_ilog(self, mock_caler, mock_logging, mock_datetime, mock_path):
        mock_path.exists.return_value = https://www.cnblogs.com/CHLL55/p/True
        log_init()
        self.assertFalse(mock_logging.getLogger('debug').info.called, "Failed to not write log.")
        mock_caler.return_value = https://www.cnblogs.com/CHLL55/p/('qk_log_test', 12, '')
        mock_datetime.now.return_value = https://www.cnblogs.com/CHLL55/p/self.dt_str
        ilog('any msg')
        mock_logging.getLogger('debug').info.assert_called_with(
            '[%s] [%s] [%s,%d] %s' % ('2017-10-11 11:08:59', 'info', 'qk_log_test', 12, 'any msg'))

    @mock.patch('qk_log.os.path')
    @mock.patch('qk_log.datetime.datetime')
    @mock.patch('qk_log.logging')
    @mock.patch('qk_log.find_caler')
    def test_wlog(self, mock_caler, mock_logging, mock_datetime, mock_path):
        mock_path.exists.return_value = https://www.cnblogs.com/CHLL55/p/True
        log_init()
        self.assertFalse(mock_logging.getLogger('warn').info.called, "Failed to not write log.")
        mock_caler.return_value = https://www.cnblogs.com/CHLL55/p/('qk_log_test', 12, '')
        mock_datetime.now.return_value = https://www.cnblogs.com/CHLL55/p/self.dt_str
        wlog('any msg')
        mock_logging.getLogger('warn').warn.assert_called_with(
            '[%s] [%s] [%s,%d] %s' % ('2017-10-11 11:08:59', 'warning', 'qk_log_test', 12, 'any msg'))

    @mock.patch('qk_log.os.path')
    @mock.patch('qk_log.datetime.datetime')
    @mock.patch('qk_log.logging')
    @mock.patch('qk_log.find_caler')
    def test_elog(self, mock_caler, mock_logging, mock_datetime, mock_path):
        mock_path.exists.return_value = https://www.cnblogs.com/CHLL55/p/True
        log_init()
        self.assertFalse(mock_logging.getLogger('error').info.called, "Failed to not write log.")
        mock_caler.return_value = https://www.cnblogs.com/CHLL55/p/('qk_log_test', 12, '')
        mock_datetime.now.return_value = https://www.cnblogs.com/CHLL55/p/self.dt_str
        elog('any msg')
        mock_logging.getLogger('error').error.assert_called_with(
            '[%s] [%s] [%s,%d] %s' % ('2017-10-11 11:08:59', 'error', 'qk_log_test', 12, 'any msg'))

if __name__ == '__main__':
    unittest.main()

對單元測驗的看法

在一次整體改造Python資料統計分析專案時打算引進單元測驗，在寫完公共庫的單元測驗之后發現花費在單元測驗上的時間較多，而且公共庫不常改動，業務邏輯有比較混亂，因此團隊決定放棄單元測驗，對于以快速上線的初創公司和初創團隊的專案來說，可以不用急著寫單元測驗，因為在一切改動都可能發生的情況下，再代碼丟棄的時候對應的單元測驗也就被丟棄了，浪費了過多的人力，

因此，初創團隊不建議寫單元測驗，做好程式埋點和監控報警即可，

記得幫我點贊哦！