Pytest fixture for a class through self not as method argument

问题

Often I'll write a test class that uses a pytest fixture in every method. Here's an example. I'd like to be able to avoid having to write the fixture name in the signature of every method. It's not DRY. How can this be done?

I would like to be able to access the fixture by giving the fixture as an attribute of the test class. In this example, I would like to see the google fixture as an attribute of TestGoogle. Is this possible?

from bs4 import BeautifulSoup
import pytest
import requests

@pytest.fixture()
def google():
    return requests.get("https://www.google.com")


class TestGoogle:
    def test_alive(self, google):
        assert google.status_code == 200

    def test_html_title(self, google):
        soup = BeautifulSoup(google.content, "html.parser")
        assert soup.title.text.upper() == "GOOGLE"

回答1:

Sure, just use an autouse fixture. Here is the relevant spot in pytest docs. In your example, the change would be introducing an extra fixture (I named it _request_google_page):

from bs4 import BeautifulSoup
import pytest
import requests

@pytest.fixture()
def google():
    return requests.get("https://www.google.com")


class TestGoogle:

    @pytest.fixture(autouse=True)
    def _request_google_page(self, google):
        self._response = google

    def test_alive(self):
        assert self._response.status_code == 200

    def test_html_title(self):
        soup = BeautifulSoup(self._response.content, "html.parser")
        assert soup.title.text.upper() == "GOOGLE"

You could even drop the google fixture completely and move the code to _request_google_page:

@pytest.fixture(autouse=True)
def _request_google_page(self):
    self._response = requests.get("https://www.google.com")

Note that _request_google_page will be called once per test by default, so each test will get a new response. If you want the response to be initialized once and reused throughout all tests in the TestGoogle class, adjust the fixture scopes (scope='class' for _request_google_page and scope='module' or scope='session' for google).

来源：https://stackoverflow.com/questions/50132703/pytest-fixture-for-a-class-through-self-not-as-method-argument

标签

python

unit-testing

pytest