2023年pytest自动化测试框架教程 - 断言 - assert

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import requests

def get_user_info_api(user_id: int):
  	"""
  	获取指定user_id的用户信息并返回
  	"""
    payload = {'user_id': user_id}
	  response = requests.get('https://www.example.com/user', params=payload)
	  return response.json()
	  
def test_api_status():
  	"""
  	判定接口返回的`code`是否为`200`
  	"""
    code = get_user_info_api(user_id=1)['code']
    assert code == 200
    # assert code == 200, '返回的code非200,请检查.'  可以指定断言的msg
    

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import pytest


def test_zero_division():
    """
    1 / 0 会引发`ZeroDivisionError`异常，`pytest.raises()`捕获到预期的异常，用例执行成功
    相当于`python`中的`try except`捕获异常
    """
    with pytest.raises(ZeroDivisionError):
        1 / 0
    # 成功捕获后，做一些其他操作

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def test_no_zero_division():
    """
    如果没有发生预期的异常，则该测试用例会执行失败
    """
    with pytest.raises(ZeroDivisionError):
        1 / 1
    # def test_zero_division():
    #     with pytest.raises(ZeroDivisionError):
    # >       1 / 1
    # E   Failed: DID NOT RAISE <class 'ZeroDivisionError'>

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import pytest

def test_user_status_value():
    """
		exc_info是`ExceptionInfo`的实例
    """
    with pytest.raises(ValueError) as exc_info:
        raise ValueError('用户状态必须为0.')
    assert exc_info.type is ValueError
    assert exc_info.value.args[0] == '用户状态必须为0.'  # 要获取到实际的value，需要用`.args[0]`
    assert exc_info.traceback is None
    
    # >       assert exc_info.traceback is None
    # E       AssertionError: assert [<TracebackEntry /Users/xxx/Desktop/pytest-starter/test_raise.py:53>] is None
    # E        +  where [<TracebackEntry /Users/xxx/Desktop/pytest-starter/test_raise.py:53>] = <ExceptionInfo ValueError('用户状态必须为0.') tblen=1>.traceback

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import pytest

# 正则匹配异常
def test_match_raise():
    """
    正则匹配异常
    """
    with pytest.raises(ValueError, match=r".* 1234 .*"):  # 底层通过`re.search`来正则匹配
        raise ValueError("Exception 123 raised")
    # with pytest.raises(ValueError, match=r".* 1234 .*"):
    # >    raise ValueError("Exception 123 raised")
    # E    AssertionError: Regex pattern did not match.
    # E    Regex: '.* 1234 .*'
    #      Input: 'Exception 123 raised'

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import pytest

@pytest.mark.xfail()
def test_expected_fail():
    """
    执行失败的用例，会被标记为`XFAIL`
    """
    assert '这个用例预期会失败' == ''  # test_raise.py::test_expected_fail XFAIL
    
@pytest.mark.xfail()
def test_expected_fail():
    """
    执行成功的用例，会被标记为`XPASS`
    """
    assert 1 == 1  # test_raise.py::test_expected_fail XPASS
    

class TestXfail():
    """
    被`@pytest.mark.xfail()`标记后，不会影响后续用例执行
    """
    @pytest.mark.xfail()
    def test_expected_fail(self):
        assert 1 == 2

    def test_success(self):
        assert 1 == 1
    # test_raise.py::TestXfail::test_expected_fail XFAIL
    # test_raise.py::TestXfail::test_success PASSED

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import pytest

pytest.raises(ExpectedException, func, *args, **kwargs)
# 可以传递一个将使用给定的 *args 和 **kwargs 执行的func，并断言引发了给定的ExpectedException