Pytest - 钩子函数

• pytest_assertrepr_compare(op,left,right):

class Foo:
    def __init__(self,value):
        self.value = value

def test_foo_commpare():
    f1 = Foo(1)
    f2 = Foo(2)
    assert f1 == f2

运行结果：断言失败提示信息不够清晰

如何解决？

方式一：
重写__repr__方法：

class Foo:
    def __init__(self,value):
        self.value = value

    def __repr__(self):
        return self.__class__.__name__ + f"({self.value})"


def test_foo_commpare():
    f1 = Foo(1)
    f2 = Foo(2)
    assert f1 == f2

方法二：

# @File:conftest.py
from test_scripts.test_assert_hook import Foo

def pytest_assertrepr_compare(op,left,right):
    if isinstance(left, Foo) and isinstance(right,Foo) and op == '==':
        return [
            "比较两个实例的值",
            f'{left.value} != {right.value}'
        ]

运行结果：

======================================================================= test session starts =======================================================================
platform win32 -- Python 3.10.1, pytest-7.2.0, pluggy-1.0.0 -- e:\pyproject\pytestdemo\venv\scripts\python.exe
cachedir: .pytest_cache
rootdir: E:\PyProject\pytestDemo
collected 3 items                                                                                                                                                   

test_scripts/test_assert_hook.py::test_foo_commpare FAILED                                                                                                   [ 33%]
test_scripts/test_importtoskip.py::test_sample[4-2] PASSED                                                                                                   [ 66%] 
test_scripts/test_importtoskip.py::test_sample[XPASS] XPASS                                                                                                  [100%] 

============================================================================ FAILURES ============================================================================= 
________________________________________________________________________ test_foo_commpare ________________________________________________________________________ 

    def test_foo_commpare():
        f1 = Foo(1)
        f2 = Foo(2)
>       assert f1 == f2
E       assert 比较两个实例的值
E         1 != 2

test_scripts\test_assert_hook.py:17: AssertionError
===================================================================== short test summary info ===================================================================== 
FAILED test_scripts/test_assert_hook.py::test_foo_commpare - assert 比较两个实例的值
============================================================= 1 failed, 1 passed, 1 xpassed in 0.10s ============================================================== 

https://www.cnblogs.com/congyinew/p/16483675.html