主要實現語法有patch, patch.object, Mock()。

下面的測試太赤裸裸了，只是為了熟悉語法。

import unittest
from unittest.mock import patch, Mock


def multiply(x, y):
    return x * y


class Calculator:
    def add(self, a, b):
        return a + b


class TestMock(unittest.TestCase):
    def setUp(self):
        self.calcu 
 
= Calculator()
        self.multiply = multiply

    @patch('__main__.multiply')
    def test_patch_multiply(self, mock_multiply):
        mock_multiply.return_value = 34
        self.assertEqual(multiply(4, 5), 34)

    @patch.object(Calculator, 'add')
    def test_patch_add(self, mock_add):
        mock_add.return_value 
 
= 55
        self.assertEqual(self.calcu.add(4, 6), 55)

    def test_mock_multiply(self):
        mock_multiply = Mock(return_value=35)
        self.multiply = mock_multiply
        self.assertEqual(self.multiply(4, 5), 35)

    def test_mock_add(self):
        mock_add = Mock(return_value=99)
        self.calcu.add 
 
= mock_add
        self.assertEqual(self.calcu.add(4, 6), 99)


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

最適合mock測試，是網上那個例子，測試上一層功能，將其下一層mock掉。

client.py

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

import requests


def send_request(url):
    r = requests.get(url)
    return r.status_code


def visit_ustack():
    return send_request('http://www.ustack.com')

tests.py

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

import unittest

import mock

import client


class TestClient(unittest.TestCase):

    def test_success_request(self):
        success_send = mock.Mock(return_value='200')
        client.send_request = success_send
        self.assertEqual(client.visit_ustack(), '200')

    def test_fail_request(self):
        fail_send = mock.Mock(return_value='404')
        client.send_request = fail_send
        self.assertEqual(client.visit_ustack(), '404')