Python pytest Mock中的模拟线程调用

我有一个简单的代码库，如下所示：

import threading
import time

class Demo:
    def __init__(self):
        self._run_thread = False

    def start(self):
        if not self._run_thread:
            print("Thread has not run")
            threading.Thread(target=self.counter, args=(20, )).start()
            return 20
        else:
            print("Thread has run")
            return None


    def counter(self, value):
        self._run_thread = True
        for i in range(value):
            print(f"Inside counter with value {i}")
            time.sleep(3)



if __name__ == "__main__":
    d = Demo()
    d.start()
    d.start()

第一次调用

start

函数时，线程将运行，下一次调用时不会运行，因为设置了标志（_run_thread）

代码本身运行得非常好

但是，当我尝试对这段代码运行测试时，它并没有像预期的那样工作。下面是我的测试代码：

import app

def dummy_counter(self, value):
    self._run_thread = True

def test_app_start_function_runs_well(mocker):
    d = app.Demo()
    mocker.patch.object(
        d,
        "counter",
        dummy_counter
    )
    d.start()
    result = d.start()
    assert result is None

因此，由于我不希望循环实际运行，我只想模拟

计数器

函数，然后在其内部设置标志，以便实际线程不会运行

我看到下面的错误

(roughwork) ➜  threads git:(master) ✗ pytest
============================================================ test session starts ============================================================
platform linux -- Python 3.7.6, pytest-5.4.3, py-1.8.1, pluggy-0.13.1
rootdir: /home/subhayan/Codes/Test/Python-remote/threads
plugins: mock-3.1.1
collected 1 item                                                                                                                            

test_app.py Exception in thread Thread-2:
Traceback (most recent call last):
  File "/home/subhayan/anaconda3/envs/roughwork/lib/python3.7/threading.py", line 926, in _bootstrap_inner
    self.run()
  File "/home/subhayan/anaconda3/envs/roughwork/lib/python3.7/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
TypeError: dummy_counter() missing 1 required positional argument: 'value'

F                                                                                                                         [100%]

================================================================= FAILURES ==================================================================
____________________________________________________________ test_app_runs_well _____________________________________________________________

mocker = <pytest_mock.plugin.MockFixture object at 0x7f922c05ee90>

    def test_app_runs_well(mocker):
        d = app.Demo()
        mocker.patch.object(
            d,
            "counter",
            dummy_counter
        )
        d.start()
        result = d.start()
>       assert result is None
E    assert 20 is None

test_app.py:15: AssertionError
----------------------------------------------------------- Captured stdout call ------------------------------------------------------------
Thread has not run
Thread has not run
----------------------------------------------------------- Captured stderr call ------------------------------------------------------------
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/home/subhayan/anaconda3/envs/roughwork/lib/python3.7/threading.py", line 926, in _bootstrap_inner
    self.run()
  File "/home/subhayan/anaconda3/envs/roughwork/lib/python3.7/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
TypeError: dummy_counter() missing 1 required positional argument: 'value'

========================================================== short test summary info ==========================================================
FAILED test_app.py::test_app_runs_well - assert 20 is None

（粗活）➜  线程git:（主线程）✗ 皮特斯特
=======================================================================================测试会话开始============================================================
平台linux——Python 3.7.6、pytest-5.4.3、py-1.8.1、pluggy-0.13.1
rootdir:/home/subhayan/code/Test/Python remote/threads
插件：mock-3.1.1
收集1项
线程2中的test_app.py异常：
回溯（最近一次呼叫最后一次）：
文件“/home/subhayan/anaconda3/envs/rawwork/lib/python3.7/threading.py”，第926行，在内部引导中
self.run（）
文件“/home/subhayan/anaconda3/envs/rawwork/lib/python3.7/threading.py”，第870行，运行中
自我目标（*自我参数，**自我参数）
TypeError:dummy_counter（）缺少1个必需的位置参数：“value”
F[100%]
======================================================================================================故障==================================================================
____________________________________________________________测试应用程序运行良好_____________________________________________________________
嘲弄者=
def测试应用程序运行良好（模拟程序）：
d=app.Demo（）
mocker.patch.object(
D
“柜台”，
虚拟计数器
)
d、 开始（）
结果=d.开始（）
>断言结果为无
E断言20是零
测试应用程序py:15:AssertionError
-----------------------------------------------------------捕获的stdout调用------------------------------------------------------------
线程尚未运行
线程尚未运行
-----------------------------------------------------------捕获的stderr调用------------------------------------------------------------
线程1中的异常：
回溯（最近一次呼叫最后一次）：
文件“/home/subhayan/anaconda3/envs/rawwork/lib/python3.7/threading.py”，第926行，在内部引导中
self.run（）
文件“/home/subhayan/anaconda3/envs/rawwork/lib/python3.7/threading.py”，第870行，运行中
自我目标（*自我参数，**自我参数）
TypeError:dummy_counter（）缺少1个必需的位置参数：“value”
=================================================================================================简短测试摘要信息==========================================================
失败的测试应用程序。py:：测试应用程序运行良好-断言20为无

我不知道哪里出了问题。如果有任何线索，我将不胜感激