在pytest中，如何访问传递给测试的参数？

Question

In pytest, I can pass parameters to test (using fixtures or the decorator @pytest.fixture(params=list-of-params) ).

When the tests are done, if a test fails, the parameter that was passed is shown on the results, as in TestCheckoutPage.test_address_edit[True] or False if it was false.

How can I access those parameters and add them to a finalizer? request.param doesn't seem to work, even though that is how you would get the parameter when making a fixture:

@pytest.fixture(params=[True, False])
def user(request):
    return request.param

That works. But if I try to pass it to a test:

class TestClass:
    def test_something(self, user):
        pass

And then, using an autouse fixture to collect info on it:

@pytest.fixture(autouse=True)
def set_driver(self, request):
    print request.param

That throws an error, saying there is no param in FixtureRequest .

Is there a way that I can get that parameter back? I'm trying to have Selenium take a screenshot when tests fail, but because tests with parameters have the same name and classname and all, it is writing a file for the first execution, and then overwriting it the second, third, ..., time around. So I would like to add the parameter to the file name to avoid this.

Thanks!

Answer 1

Indeed, request.param is only available in the fixture function where the parametrization is defined. If you need user in the set_driver fixture you can try this:

import pytest

@pytest.fixture(params=[True, False])
def user(request):
    return request.param

class TestHello:
    @pytest.fixture(autouse=True)
    def set_driver(self, user):
        print "set_driver sees", user

    def test_method(self):
        assert 0

If you only want to have set_driver do something if user is actually involved in the test, then you could do something like this:

import pytest

@pytest.fixture(params=[True, False], scope="module")
def user(request):
    return request.param

@pytest.fixture(autouse=True)
def set_driver(request):
    if "user" in request.fixturenames:
        user = request.getfuncargvalue("user")
        print "set_driver sees", user


def test_function(user):
    assert 0

def test_function_nouser():
    assert 0