Question

我想将命令行参数传递给py.test来创建夹具。例如，我想将数据库主机名传递给下面的夹具创建，因此它不会被硬编码：

import pytest

def pytest_addoption(parser):
    parser.addoption("--hostname", action="store", default='127.0.0.1', help="specify IP of test host")

@pytest.fixture(scope='module')
def db(request):
    return 'CONNECTED TO [' + request.config.getoption('--hostname') + '] SUCCESSFULLY!'

def test_1(db):
    print db
    assert 0

不幸的是，如果从命令行中省略了参数，则不设置默认值：

$ py.test test_opt.py
=================================================================== test session starts ====================================================================
platform linux2 -- Python 2.7.5 -- pytest-2.3.5
collected 1 items

test_opt.py E

========================================================================== ERRORS ==========================================================================
_________________________________________________________________ ERROR at setup of test_1 _________________________________________________________________

request = <FixtureRequest for <Module 'test_opt.py'>>

    @pytest.fixture(scope='module')
    def db(request):
>       return 'CONNECTED TO [' + request.config.getoption('--hostname') + '] SUCCESSFULLY!'

test_opt.py:8:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <_pytest.config.Config object at 0x220c4d0>, name = '--hostname'

    def getoption(self, name):
        """ return command line option value.

            :arg name: name of the option.  You may also specify
                the literal ``--OPT`` option instead of the "dest" option name.
            """
        name = self._opt2dest.get(name, name)
        try:
            return getattr(self.option, name)
        except AttributeError:
>           raise ValueError("no option named %r" % (name,))
E           ValueError: no option named '--hostname'

我错过了什么？ ...顺便说一句，在命令行上指定主机名也会失败：

$ py.test --hostname=192.168.0.1 test_opt.py
Usage: py.test [options] [file_or_dir] [file_or_dir] [...]

py.test: error: no such option: --hostname

TIA！

Answer 1

文件的布局是什么？您似乎正在尝试将所有这些代码放在test_opt.py模块中。但是，pytest_addoption()挂钩只能从conftest.py文件中读取。因此，您应该尝试将pytest_addoption()函数移动到与test_opt.py相同的目录中的conftest.py文件。

通常，虽然可以在测试模块中定义fixture，但是任何钩子都需要放在conftest.py文件中以供py.test使用。

从命令行为py.test指定fixture参数

1 个答案: