Question

会话范围的fixture有效地访问所有收集的测试项。下面是fixture函数的一个示例，该函数遍历所有收集的测试，并查看它们的测试类是否定义了 callme 方法并调用它：

# content of conftest.py

import pytest


@pytest.fixture(scope="session", autouse=True)
def callattr_ahead_of_alltests(request):
    print("callattr_ahead_of_alltests called")
    seen = {None}
    session = request.node
    for item in session.items:
        cls = item.getparent(pytest.Class)
        if cls not in seen:
            if hasattr(cls.obj, "callme"):
                cls.obj.callme()
            seen.add(cls)

测试类现在可以定义 callme 将在运行任何测试之前调用的方法：

# content of test_module.py


class TestHello:
    @classmethod
    def callme(cls):
        print("callme called!")

    def test_method1(self):
        print("test_method1 called")

    def test_method2(self):
        print("test_method1 called")


class TestOther:
    @classmethod
    def callme(cls):
        print("callme other called")

    def test_other(self):
        print("test other")


# works with unittest as well ...
import unittest


class SomeTest(unittest.TestCase):
    @classmethod
    def callme(self):
        print("SomeTest callme called")

    def test_unit1(self):
        print("test_unit1 method called")

如果在不捕获输出的情况下运行此命令：

$ pytest -q -s test_module.py
callattr_ahead_of_alltests called
callme called!
callme other called
SomeTest callme called
test_method1 called
.test_method1 called
.test other
.test_unit1 method called
.
4 passed in 0.12s