python - 在pytest中并行运行参数化测试

Question

我想并行运行参数化测试函数。这适用于并发测试场景。同一测试用例在设备中以不同参数并行运行。完成一个测试函数的所有参数化变体后，我想继续下一个。

如果我们以这个简单的例子为例，我想并行运行 test_even 的所有 4 个实例，然后移动到 test_odd。

@pytest.mark.parametrize("x", range(4))
def test_even(x):
    assert x % 2 == 0        
@pytest.mark.parametrize("x", range(4))
def test_odd(x):
    assert x % 2 != 0

可以在pytest中做吗？我检查了 xdist，但找不到这种类型的支持。有人可以就如何在 pytest 中实现这一点给出一些指示吗？

Answer 1

我建议使用 xdist ，从他们的网站上可以:

The pytest-xdist plugin extends pytest with new test execution modes, the most used being distributing tests across multiple CPUs to speed up test execution...

默认情况下，它还会并行化您的参数化测试。

这是一个例子:

import pytest

@pytest.mark.parametrize("foo", range(10))
def test_bar(foo):
    assert True

pytest -n 2 -v
================================================================================================ test session starts ================================================================================================
platform linux -- Python 3.10.4, pytest-7.1.2, pluggy-1.0.0 -- /tmp/test/venv/bin/python3
cachedir: .pytest_cache
rootdir: /tmp/test
plugins: xdist-2.5.0, forked-1.4.0
[gw0] linux Python 3.10.4 cwd: /tmp/test
[gw1] linux Python 3.10.4 cwd: /tmp/test
[gw0] Python 3.10.4 (main, Apr  2 2022, 09:04:19) [GCC 11.2.0]
[gw1] Python 3.10.4 (main, Apr  2 2022, 09:04:19) [GCC 11.2.0]
gw0 [10] / gw1 [10]
scheduling tests via LoadScheduling

test/test_foo.py::test_bar[1] 
test/test_foo.py::test_bar[0] 
[gw1] [ 10%] PASSED test/test_foo.py::test_bar[1] 
[gw0] [ 20%] PASSED test/test_foo.py::test_bar[0] 
test/test_foo.py::test_bar[3] 
[gw1] [ 30%] PASSED test/test_foo.py::test_bar[3] 
test/test_foo.py::test_bar[2] 
test/test_foo.py::test_bar[4] 
[gw0] [ 40%] PASSED test/test_foo.py::test_bar[2] 
[gw1] [ 50%] PASSED test/test_foo.py::test_bar[4] 
test/test_foo.py::test_bar[6] 
test/test_foo.py::test_bar[5] 
[gw1] [ 60%] PASSED test/test_foo.py::test_bar[6] 
[gw0] [ 70%] PASSED test/test_foo.py::test_bar[5] 
test/test_foo.py::test_bar[8] 
test/test_foo.py::test_bar[7] 
[gw1] [ 80%] PASSED test/test_foo.py::test_bar[8] 
test/test_foo.py::test_bar[9] 
[gw0] [ 90%] PASSED test/test_foo.py::test_bar[7] 
[gw1] [100%] PASSED test/test_foo.py::test_bar[9] 

================================================================================================ 10 passed in 0.28s =================================================================================================