pytest扫盲11--xfail参数详解

xfail 函数文档如下：

    def xfail(self,condition=None, reason=None, raises=None, run=True, strict=False):
        """mark the the test function as an expected failure if eval(self,condition)
        has a True value.　　# 将eval(self,condition)为真的测试函数标记为失败。

        Optionally specify a reason for better reporting and run=False if
        you don't even want to execute the test function.　　# 不想执行某个测试功能，可以指定 run=False，可以自定义错误原因 reason=‘’

        See http://doc.pytest.org/en/latest/skipping.html　　# 官方文档说明
        """

xfail 作用：

　　1）xfail意味着你期望测试由于某种原因失败。常见的示例是对尚未实现的功能或尚未修复的错误进行测试。

　　2）当预期失败时（标记为pytest.mark.xfail），但实际测试通过，标记为xpass，用 x 标记代替 F，但无错误信息输出，将在测试摘要中报告

　　3）使用 pytest.xfail(reason) 从用例中强制标记测试。

　　4）通过 -r 显示 xfail、skip 详细信息 　　pytest -r

 　   5）忽略xfail：

pytest --runxfail

1）直接使用 @pytest.mark.xfail

# File  : test_demo_10_xfail.py
# IDE   : PyCharm

import pytest

def division(a, b):
    return int(a / b)

@pytest.mark.xfail
@pytest.mark.parametrize('a, b, c', [(4, 2, 2), (0, 2, 0), pytest.param(1, 0, 0, marks=pytest.mark.xfail), (6, 8, 0)], ids=['整除', '被除数为0', '除数为0', '非整除'])
def test_1(a, b, c):
    res = division(a, b)
    assert res == c

执行（使用xfail标记的用例仍然会执行）：

• xfailed  为失败的用例，小写 x
• xpassed  为通过的用例，大写 X

E:personalpython38python.exe E:/personal/GitWorkSpace/pytest_basic/main.py
test_demo_10_xfail.py::test_1[整除]
test_demo_10_xfail.py::test_1[被除数为0]
test_demo_10_xfail.py::test_1[除数为0]
test_demo_10_xfail.py::test_1[非整除]
XXxX
1 xfailed, 3 xpassed in 0.12s

Process finished with exit code 0

2）condition  为False执行标记的代码块，True则标记 xpass

@pytest.mark.xfail(condition=True, reason='xfail标记')
@pytest.mark.parametrize('a, b, c', [(4, 2, 2), (0, 2, 0), pytest.param(1, 0, 0, marks=pytest.mark.xfail), (6, 8, 0)], ids=['整除', '被除数为0', '除数为0', '非整除'])
def test_1(a, b, c):
    res = division(a, b)
    assert res == c

执行：

E:personalpython38python.exe E:/personal/GitWorkSpace/pytest_basic/main.py
test_demo_10_xfail.py::test_1[整除]
test_demo_10_xfail.py::test_1[被除数为0]
test_demo_10_xfail.py::test_1[除数为0]
test_demo_10_xfail.py::test_1[非整除]
test_demo_10_xfail.py::test_2
XXxX.
1 passed, 1 xfailed, 3 xpassed in 0.14s

Process finished with exit code 0

3）raises  具体原因，python标准错误类型，可以在raises参数中指定单个异常或异常组

• 如果测试失败且没有提到指定的异常，则报告failed
• 如果测试失败，raises 报告的异常与失败异常一致，则标记为 xfailed

@pytest.mark.xfail(raises=AssertionError)
def test_03():
    assert 3 == 4

@pytest.mark.xfail(raises=ValueError)
def test_04():
    if isinstance('1234', int) is False:
        raise TypeError("传入参数非整数")

E:personalpython38python.exe E:/personal/GitWorkSpace/pytest_basic/main.py
test_demo_10_xfail.py::test_03
test_demo_10_xfail.py::test_04
xF
================================== FAILURES ===================================
___________________________________ test_04 ___________________________________

    @pytest.mark.xfail(raises=ValueError)
    def test_04():
        if isinstance('1234', int) is False:
>           raise TypeError("传入参数非整数")
E           TypeError: 传入参数非整数

test_demo_10_xfail.py:41: TypeError
=========================== short test summary info ===========================
FAILED test_demo_10_xfail.py::test_04 - TypeError: 传入参数非整数
1 failed, 1 xfailed in 0.14s

Process finished with exit code 0

4）run=False 直接标记为xfail，且不执行，防止在xfail死循环（默认为True执行用例）

@pytest.mark.xfail(run=False)
@pytest.mark.parametrize('a, b, c', [(4, 2, 2), (0, 2, 0), pytest.param(1, 0, 0, marks=pytest.mark.xfail), (6, 8, 0)], ids=['整除', '被除数为0', '除数为0', '非整除'])
def test_1(a, b, c):
    res = division(a, b)
    assert res == c

E:personalpython38python.exe E:/personal/GitWorkSpace/pytest_basic/main.py
test_demo_10_xfail.py::test_1[整除]
test_demo_10_xfail.py::test_1[被除数为0]
test_demo_10_xfail.py::test_1[除数为0]
test_demo_10_xfail.py::test_1[非整除]
xxxx
4 xfailed in 0.27s

Process finished with exit code 0

5）strict=True  会使产生了 xpass 的用例，标记为测试失败（默认False则标记通过）

@pytest.mark.xfail(strict=True)
def test_05():
    assert 3 == 3

执行结果（只要 strict=True 的用例均会失败）：

E:personalpython38python.exe E:/personal/GitWorkSpace/pytest_basic/main.py
test_demo_10_xfail.py::test_05
F
================================== FAILURES ===================================
___________________________________ test_05 ___________________________________
[XPASS(strict)] 
=========================== short test summary info ===========================
FAILED test_demo_10_xfail.py::test_05
1 failed in 0.07s

Process finished with exit code 0

5）在 parametrize 中使用  marks=pytest.mark.xfail

@pytest.mark.parametrize('a, b, c', [(4, 2, 2), (0, 2, 0), pytest.param(1, 0, 0, marks=pytest.mark.xfail), (6, 8, 0)], ids=['整除', '被除数为0', '除数为0', '非整除'])
def test_1(a, b, c):
    res = division(a, b)
    assert res == c

E:personalpython38python.exe E:/personal/GitWorkSpace/pytest_basic/main.py
test_demo_10.py::test_1[整除]
test_demo_10.py::test_1[被除数为0]
test_demo_10.py::test_1[除数为0]
test_demo_10.py::test_1[非整除]
..x.
3 passed, 1 xfailed in 0.14s