Question

据我所知，您可以参数化测试以使用不同的参数集重复测试。另外我知道测试文件中的不同测试可以使用-n并行运行，但我想并行执行同一组测试。在pytest中有可能吗？

例如：

import pytest

@pytest.fixture()
def user_number(worker_id):
    return "user number : %s" %worker_id

def test_add(user_number):
    print("Adding 1+1 and returning the result and user number: {}".format(user_number))
    return 1+1

def test_subtract():
    print("subtracting 2-1 and returning the result and user number: {}".format(user_number))
    return 2-1

如果我运行以下命令： py.test -n 3 -s -v parallel_users.py

在结果中，test_add（）和test_subtract（）并行运行，如下所示：

[gw1] PASSED parallel_users.py::test_subtract 
[gw0] PASSED parallel_users.py::test_add

如何让test_add（）和test_subtract（）运行两次，如下所示：

[gw1] PASSED parallel_users.py::test_add, test_subtract 
[gw0] PASSED parallel_users.py::test_add, test_subtract

Answer 1

要重复执行测试，请在conftest.py：

中添加一个挂钩

def pytest_collection_modifyitems(items):
    numrepeats = 2
    items.extend(items * (numrepeats - 1))

这将复制为执行numrepeats次收集的每个测试。示例运行：

$ pytest test_spam.py -v -n3
============================= test session starts ==============================
platform darwin -- Python 3.6.4, pytest-3.4.2, py-1.5.3, pluggy-0.6.0 -- /Users/hoefling/.virtualenvs/stackoverflow/bin/python3.6
cachedir: .pytest_cache
rootdir: /private/tmp, inifile:
plugins: xdist-1.22.2, forked-0.2, dependency-0.3.2, cov-2.5.1
[gw0] darwin Python 3.6.4 cwd: /private/tmp
[gw1] darwin Python 3.6.4 cwd: /private/tmp
[gw2] darwin Python 3.6.4 cwd: /private/tmp
[gw0] Python 3.6.4 (v3.6.4:d48ecebad5, Dec 18 2017, 21:07:28)  -- [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)]
[gw1] Python 3.6.4 (v3.6.4:d48ecebad5, Dec 18 2017, 21:07:28)  -- [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)]
[gw2] Python 3.6.4 (v3.6.4:d48ecebad5, Dec 18 2017, 21:07:28)  -- [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)]
gw0 [4] / gw1 [4] / gw2 [4]
scheduling tests via LoadScheduling

test_spam.py::test_add
test_spam.py::test_subtract
test_spam.py::test_add
[gw0] [ 25%] PASSED test_spam.py::test_add
[gw1] [ 50%] PASSED test_spam.py::test_subtract
[gw2] [ 50%] PASSED test_spam.py::test_add
test_spam.py::test_subtract
[gw0] [ 50%] PASSED test_spam.py::test_subtract

=========================== 4 passed in 0.63 seconds ===========================

如果要使其可配置，请添加自定义cli参数：

import pytest

def pytest_addoption(parser):
    parser.addoption('--numrepeats', action='store', type=int, default=1)

def pytest_collection_modifyitems(items):
    numrepeats = pytest.config.getoption('--numrepeats')
    items.extend(items * (numrepeats - 1))

现在，您可以使用--numrepeats来调用您的测试，例如pytest --numrepeats 5。

至于每个流程的批处理测试（问题的第二部分），pytest-xdist尚不支持，请参阅this issue以及与之关联的所有内容。最近，添加了一些基本的支持，例如在单个模块或类中在单独的进程中执行测试：

--dist=distmode       set mode for distributing tests to exec environments.
                      each: send each test to all available environments.
                      load: load balance by sending any pending test to any
                      available environment. loadscope: load balance by
                      sending pending groups of tests in the same scope to
                      any available environment. loadfile: load balance by
                      sending test grouped by file to any available
                      environment. (default) no: run tests inprocess, don't
                      distribute.

但是，如果您想根据某些自定义条件对测试进行负载均衡，除了编写自己的调度程序之外别无他法。

Answer 2

实现此目的的一种最简单方法是欺骗py.test以假设使用pytest.mark.parametrization进行多种测试组合。在这里，我只是使用虚拟参数count来欺骗py.test，有多个测试变体。这是最简单的方法，如果您有更多的测试条件，可以使用pytest_generate_tests(metafunc):来微调您的需求。

import pytest

@pytest.fixture()
def user_number(worker_id):
    return "user number : %s" %worker_id

@pytest.mark.parametrize("count", [1, 2,3])
def test_add(user_number, count):
    print("Adding 1+1 and returning the result and user number: {}".format(user_number))
    return 1+1

@pytest.mark.parametrize("count", [1, 2 ,3])
def test_subtract(count):
    print("subtracting 2-1 and returning the result and user number: {}".format(user_number))
    return 2-1

$ py.test test.py -n 2 -s -vv
======================================== test session starts ========================================
platform darwin -- Python 2.7.13, pytest-2.9.2, py-1.5.3, pluggy-0.3.1 -- bin/python2.7
cachedir: .cache
rootdir: , inifile:
plugins: xdist-1.17.1, repeat-0.4.1, cov-1.8.1
[gw0] darwin Python 2.7.13 cwd: 
[gw1] darwin Python 2.7.13 cwd: 
[gw1] Python 2.7.13 (default, Dec 17 2016, 23:03:43)  -- [GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)]
[gw0] Python 2.7.13 (default, Dec 17 2016, 23:03:43)  -- [GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)]
gw0 [6] / gw1 [6]
scheduling tests via LoadScheduling

test.py::test_add[1]
test.py::test_add[2]
[gw1] PASSED test.py::test_add[2]
[gw0] PASSED test.py::test_add[1]
test.py::test_subtract[1]
[gw1] PASSED test.py::test_subtract[1]
test.py::test_add[3]
[gw0] PASSED test.py::test_add[3]
test.py::test_subtract[3]
test.py::test_subtract[2]
[gw0] PASSED test.py::test_subtract[3]
[gw1] PASSED test.py::test_subtract[2]

可以在pytest中并行执行相同的测试吗？

2 个答案: