pytest文檔53-命令行實時輸出錯誤信息(pytest-instafail)

前言

pytest 運行全部用例的時候，在控制台會先顯示用例的運行結果(.或F), 用例全部運行完成后最后把報錯信息全部一起拋出到控制台。
這樣我們每次都需要等用例運行結束，才知道為什么報錯，不方便實時查看報錯信息。
pytest-instafail 插件可以在運行用例的時候，需實時查看用例報錯內容，這樣方便跟蹤問題。

--instafail

執行全部用例，報錯內容等用例運行完成才顯示出來

>pytest
============================= test session starts =============================

collected 11 items

test_s.py ..                                                             [ 18%]
test_t.py ...                                                            [ 45%]
test_x.py .F.F                                                           [ 81%]
test_y.py ..                                                             [100%]

================================== FAILURES ===================================
___________________________________ test_02 ___________________________________

    def test_02():
        a = "hello"
        b = "hello world"
>       assert a == b
E       AssertionError: assert 'hello' == 'hello world'
E         - hello
E         + hello world

test_x.py:12: AssertionError
___________________________________ test_04 ___________________________________

    def test_04():
        a = "hello"
        b = "hello world"
>       assert a not in b
E       AssertionError: assert 'hello' not in 'hello world'
E         'hello' is contained here:
E           hello world

test_x.py:24: AssertionError
===================== 2 failed, 9 passed in 1.32 seconds ======================

當用例很多的時候，不方便我們查看具體哪個報錯對應哪條用例，加上--instafail參數，方便實時查看報錯內容

>pytest --instafail
============================= test session starts =============================

collected 11 items

test_s.py ..                                                             [ 18%]
test_t.py ...                                                            [ 45%]
test_x.py .F

___________________________________ test_02 ___________________________________

    def test_02():
        a = "hello"
        b = "hello world"
>       assert a == b
E       AssertionError: assert 'hello' == 'hello world'
E         - hello
E         + hello world

test_x.py:12: AssertionError

test_x.py .F

___________________________________ test_04 ___________________________________

    def test_04():
        a = "hello"
        b = "hello world"
>       assert a not in b
E       AssertionError: assert 'hello' not in 'hello world'
E         'hello' is contained here:
E           hello world

test_x.py:24: AssertionError

test_y.py ..                                                             [100%]

===================== 2 failed, 9 passed in 1.37 seconds ======================

結合--tb=line參數，看起來更直觀

>pytest --instafail --tb=line
============================= test session starts =============================
collected 11 items

test_s.py ..                                                             [ 18%]
test_t.py ...                                                            [ 45%]
test_x.py .F

D:\test_x.py:12: AssertionError: assert 'hello' == 'hello world'

test_x.py .F

D:\test_x.py:24: AssertionError: assert 'hello' not in 'hello world'

test_y.py ..                                                             [100%]

===================== 2 failed, 9 passed in 1.30 seconds ======================