Mock线程调用pytest-mock
Mock线程调用pytest-mock
提问于 2020-06-15 06:08:57
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()由于设置了标志(_run_thread)，因此第一次调用start函数时，线程将运行，而下一次调用该函数时，线程将不再运行。
代码本身运行得非常好。
但是，当我尝试对此代码运行测试时，它并不能像预期的那样工作。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，由于我实际上不希望循环，所以我只想模拟counter函数，然后在它内部设置标志，这样实际的线程就不会运行。
我看到了下面的错误。
(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我不知道我错在哪里。任何线索我都会非常感激。
回答 1
Stack Overflow用户
发布于 2021-09-09 10:03:09
你几乎每件事都做对了。唯一的问题是，self.counter是一个绑定到实例的方法，所以self中填充的是您正确的d实例。但是，dummy_counter没有绑定-因此它不会自动获取第一个参数，因此您需要提供它。
一种方法是使用分部函数，如下所示：
from functools import partial
import app
def dummy_counter(self, value):
self._run_thread = True
def test_app_start_function_runs_well(mocker):
d = app.Demo()
dummy_for_d = partial(dummy_counter, d) # fills the first parameter with 'd'
mocker.patch.object(
d,
"counter",
dummy_for_d
)
d.start()
result = d.start()
assert result is None页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/62378800
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