pytest（三十一）--斷言失敗后還能繼續執行pytest-assume

前言

pytest的斷言失敗后，后面的代碼就不會執行了，通常一個用例我們會寫多個斷言，有時候我們希望第一個斷言失敗后，后面能繼續斷言。

pytest-assume插件可以解決斷言失敗后繼續斷言的問題。github地址：https://github.com/astraw38/pytest-assume

環境准備

先安裝pytest-assume依賴包

pip install pytest-assume　　

遇到問題

一下是一個簡單案例，輸入的測試數據有3種，我們需要斷言同時滿足三種情況

x==y , x+y>1 ,x>0

import pytest
@pytest.mark.parametrize(('x','y'),[(1,1),(1,0),(0,1)])
def test_simple(x,y):
    print("測試數據x:{},y:{}".format(x,y))
    assert x==y
    assert x+y>1
    assert x>0　　

運行結果

================================== FAILURES ===================================
______________________________ test_simple[1-0] _______________________________

x = 1, y = 0

    @pytest.mark.parametrize(('x','y'),[(1,1),(1,0),(0,1)])
    def test_simple(x,y):
        print("測試數據x:{},y:{}".format(x,y))
>       assert x==y
E       assert 1 == 0

test_a.py:6: AssertionError
---------------------------- Captured stdout call -----------------------------
測試數據x:1,y:0
______________________________ test_simple[0-1] _______________________________

x = 0, y = 1

    @pytest.mark.parametrize(('x','y'),[(1,1),(1,0),(0,1)])
    def test_simple(x,y):
        print("測試數據x:{},y:{}".format(x,y))
>       assert x==y
E       assert 0 == 1

test_a.py:6: AssertionError
---------------------------- Captured stdout call -----------------------------
測試數據x:0,y:1
=========================== short test summary info ===========================
FAILED test_a.py::test_simple[1-0] - assert 1 == 0
FAILED test_a.py::test_simple[0-1] - assert 0 == 1
========================= 2 failed, 1 passed in 0.16s =========================

　如果第一個斷言就失敗了，后面的2個斷言都不會執行了。

pytest-assume使用案例

使用pytest.assume斷言

#test_a.py
import pytest
@pytest.mark.parametrize(('x','y'),[(1,1),(1,0),(0,1)])
def test_simple(x,y):
    print("測試數據x:{},y:{}".format(x,y))
    pytest.assume(x==y)
    pytest.assume(x+y>1)
    pytest.assume(x>0)
    print("測試完成!")

　　運行結果

================================== FAILURES ===================================
______________________________ test_simple[1-0] _______________________________

tp = <class 'pytest_assume.plugin.FailedAssumption'>, value = None, tb = None

    def reraise(tp, value, tb=None):
        try:
            if value is None:
                value = tp()
            if value.__traceback__ is not tb:
>               raise value.with_traceback(tb)
E               pytest_assume.plugin.FailedAssumption: 
E               2 Failed Assumptions:
E               
E               test_a.py:6: AssumptionFailure
E               >>	pytest.assume(x==y)
E               AssertionError: assert False
E               
E               test_a.py:7: AssumptionFailure
E               >>	pytest.assume(x+y>1)
E               AssertionError: assert False

C:\Users\Administrator\AppData\Local\Programs\Python\Python37\lib\site-packages\six.py:695: FailedAssumption
---------------------------- Captured stdout call -----------------------------
測試數據x:1,y:0
測試完成!
______________________________ test_simple[0-1] _______________________________

tp = <class 'pytest_assume.plugin.FailedAssumption'>, value = None, tb = None

    def reraise(tp, value, tb=None):
        try:
            if value is None:
                value = tp()
            if value.__traceback__ is not tb:
>               raise value.with_traceback(tb)
E               pytest_assume.plugin.FailedAssumption: 
E               3 Failed Assumptions:
E               
E               test_a.py:6: AssumptionFailure
E               >>	pytest.assume(x==y)
E               AssertionError: assert False
E               
E               test_a.py:7: AssumptionFailure
E               >>	pytest.assume(x+y>1)
E               AssertionError: assert False
E               
E               test_a.py:8: AssumptionFailure
E               >>	pytest.assume(x>0)
E               AssertionError: assert False

C:\Users\Administrator\AppData\Local\Programs\Python\Python37\lib\site-packages\six.py:695: FailedAssumption
---------------------------- Captured stdout call -----------------------------
測試數據x:0,y:1
測試完成!
=========================== short test summary info ===========================
FAILED test_a.py::test_simple[1-0] - pytest_assume.plugin.FailedAssumption: 
FAILED test_a.py::test_simple[0-1] - pytest_assume.plugin.FailedAssumption: 
========================= 2 failed, 1 passed in 0.25s =========================

　從運行結果可以看出，三個斷言都會執行。

上下文管理器

pytest.assume也可以使用上下文管理器去斷言

#test_a.py
import pytest
from pytest import assume
@pytest.mark.parametrize(('x','y'),[(1,1),(1,0),(0,1)])
def test_simple(x,y):
    print("測試數據x:{},y:{}".format(x,y))
    with assume:assert x==y
    with assume:assert x+y>1
    with assume:assert x>0
    print("測試完成")

　這樣看起來會更優雅一點，對之前寫的代碼改起來也方便一些

需要注意的是每個with塊只能有一個斷言，如果一個with下有多個斷言，當第一個斷言失敗的時候，后面的斷言就不會起作用的。

#test_a.py
import pytest
from pytest import assume
@pytest.mark.parametrize(('x','y'),[(1,1),(1,0),(0,1)])
def test_simple(x,y):
    print("測試數據x:{},y:{}".format(x,y))
    with assume:
        assert x==y
        assert x+y>1
        assert x>0
    print("測試完成")