带有生成器的鼻子测试类，用于多个测试，但只有一个类实例

Question

我正在尝试找到一种方法来使用鼻子在一个类中运行多个测试用例，但我需要这样做，鼻子只创建该类的一个实例。此类将测试网络，网络的设置需要几分钟，因此需要通过该类的一个实例运行所有测试。这是我正在尝试做的一个基本示例：

class TestUmbrella(object):

    def __init__(self):
        log.info('__init__ called')

    def run_A(self):
        log.info('Test A is running')

    def run_B(self):
        log.info('Test B is running')

    def run_C(self):
        log.info('Test C is running')

    def run_test(self):
        for x in (self.run_A, self.run_B, self.run_C):
            yield x

这会产生：

 2015-03-19 12:22:31,330:   INFO:       tests.l3.FooTest2: __init__ called
 2015-03-19 12:22:31,331:   INFO:       tests.l3.FooTest2: __init__ called
 2015-03-19 12:22:31,331:   INFO:       tests.l3.FooTest2: Test A is running
.2015-03-19 12:22:31,331:   INFO:       tests.l3.FooTest2: __init__ called
 2015-03-19 12:22:31,332:   INFO:       tests.l3.FooTest2: Test B is running
.2015-03-19 12:22:31,332:   INFO:       tests.l3.FooTest2: __init__ called
 2015-03-19 12:22:31,332:   INFO:       tests.l3.FooTest2: Test C is running
.
----------------------------------------------------------------------
Ran 3 tests in 0.002s

OK

我想看到的是：

 2015-03-19 12:22:31,330:   INFO:       tests.l3.FooTest2: __init__ called
 2015-03-19 12:22:31,331:   INFO:       tests.l3.FooTest2: Test A is running
 2015-03-19 12:22:31,332:   INFO:       tests.l3.FooTest2: Test B is running
 2015-03-19 12:22:31,332:   INFO:       tests.l3.FooTest2: Test C is running

关于如何让鼻子做到这一点的任何想法？

Answer 1

两种方法可以得到你想要的： 为您的 TestUmbrella 使用 unittest.TestCase 类和 setUpClass：

from unittest import TestCase
import logging as log

class TestUmbrella(TestCase):
    @classmethod
    def setUpClass(cls):
        log.info('__init__ called')

    def run_A_test(self):
        log.info('Test A is running')

    def run_B_test(self):
        log.info('Test B is running')

    def run_C_test(self):
        log.info('Test C is running')

请注意，您将不再能够即时生成东西，并且必须重命名方法以符合鼻子测试模式。这会给你：

$ nosetests cls_test.py -v
INFO:root:__init__ called
run_A_test (cls_test.TestUmbrella) ... INFO:root:Test A is running
ok
run_B_test (cls_test.TestUmbrella) ... INFO:root:Test B is running
ok
run_C_test (cls_test.TestUmbrella) ... INFO:root:Test C is running
ok

----------------------------------------------------------------------
Ran 3 tests in 0.007s

OK

或者，您可以将 setup 方法注入到类中，但不能作为类初始化的一部分：

import logging as log

class TestUmbrella(object):
    def my_setup(self):
        log.info('__init__ called')

    def run_A(self):
        log.info('Test A is running')

    def run_B(self):
        log.info('Test B is running')

    def run_C(self):
        log.info('Test C is running')

    def run_test(self):
        self.my_setup()
        for x in (self.run_A, self.run_B, self.run_C):
            yield x

最后，如果你真的无法从构造函数中卸载繁重的逻辑，你可以像这样从一个独立的函数运行你的测试：

def run_test():
    tu = TestUmbrella()
    for x in (tu.run_A, tu.run_B, tu.run_C):
        yield x