Pytest單元測試系列[v1.0.0][編寫測試函數]

時間 2021-08-15

標籤 html python mysql sql session ide 函數測試 this spa 欄目 HTML 简体版

原文原文鏈接

一個規範的測試方法必定帶有斷言，在使用pytest時，能夠直接使用Python自帶的assert關鍵字html

Pytest	Unittest
assert something	assertTrue(something)
assert a==b	assertEqual(a,b)
assert a<=b	assertLessEqual(a,b)
…	…

Pytest容許在assert關鍵字添加任意表達式，表達式的值經過bool轉換後等於False則表示斷言失敗，測試用例執行失敗；若是等於True則表示斷言成功，測試用例執行成功。python

重寫assert

pytest能夠重寫assert關鍵字，它能夠截斷對原生assert的調用，替換爲pytest定義的assert，從而展現更詳細的信息和細節。mysql

from collections import namedtuple
Task = namedtuple('Task', ['summary','owner','done','id'])
# __new__.__defaults__建立默認的Task對象
Task.__new__.__defaults__ = (None, None, False, None)

import pytest


def test_task_equality():
    t1 = Task('sit there', 'brain')
    t2 = Task('do something', 'okken')
    print(t1)
    print(t2)
    assert t1 == t2


def test_dict_equal():
    t1_dict = Task('make sandwich', 'okken')._asdict()
    t2_dict = Task('make sandwich', 'okkem')._asdict()
    print(t1_dict)
    print(t2_dict)
    assert t1_dict == t2_dict

執行結果以下：sql

E:\Programs\Python\Python_Pytest\TestScripts>pytest test_three.py
=========================================== test session starts ==============================================
platform win32 -- Python 3.7.3, pytest-4.5.0, py-1.8.0, pluggy-0.11.0
rootdir: E:\Programs\Python\Python_Pytest\TestScripts
plugins: xdist-1.29.0, timeout-1.3.3, repeat-0.8.0, instafail-0.4.1, forked-1.0.2, emoji-0.2.0, allure-pytest-2.6.3
collected 2 items                                                                                                                                                          

test_three.py FF                                                                                                                                                     [100%]

================================================ FAILURES ====================================================
___________________________________________ test_task_equality _______________________________________________

    def test_task_equality():
        t1 = Task('sit there', 'brain')
        t2 = Task('do something', 'okken')
        print(t1)
        print(t2)
>       assert t1 == t2
E       AssertionError: assert Task(summary=...alse, id=None) == Task(summary='...alse, id=None)
E         At index 0 diff: 'sit there' != 'do something'
E         Use -v to get the full diff

test_three.py:14: AssertionError
---------------------------------------- Captured stdout call ------------------------------------------------
Task(summary='sit there', owner='brain', done=False, id=None)
Task(summary='do something', owner='okken', done=False, id=None)
___________________________________________ test_dict_equal __________________________________________________

    def test_dict_equal():
        t1_dict = Task('make sandwich', 'okken')._asdict()
        t2_dict = Task('make sandwich', 'okkem')._asdict()
        print(t1_dict)
        print(t2_dict)
>       assert t1_dict == t2_dict
E       AssertionError: assert OrderedDict([...('id', None)]) == OrderedDict([(...('id', None)])
E         Omitting 3 identical items, use -vv to show
E         Differing items:
E         {'owner': 'okken'} != {'owner': 'okkem'}
E         Use -v to get the full diff

test_three.py:22: AssertionError
------------------------------------------- Captured stdout call ---------------------------------------------
OrderedDict([('summary', 'make sandwich'), ('owner', 'okken'), ('done', False), ('id', None)])
OrderedDict([('summary', 'make sandwich'), ('owner', 'okkem'), ('done', False), ('id', None)])
========================================== 2 failed in 0.20 seconds===========================================

加上參數-v，執行結果以下：session

E:\Programs\Python\Python_Pytest\TestScripts>pytest test_three.py -v
=========================================== test session starts ==============================================
platform win32 -- Python 3.7.3, pytest-4.5.0, py-1.8.0, pluggy-0.11.0 -- c:\python37\python.exe
cachedir: .pytest_cache
rootdir: E:\Programs\Python\Python_Pytest\TestScripts
plugins: xdist-1.29.0, timeout-1.3.3, repeat-0.8.0, instafail-0.4.1, forked-1.0.2, emoji-0.2.0, allure-pytest-2.6.3
collected 2 items                                                                                                                                                          

test_three.py::test_task_equality FAILED                                                                                                                             [ 50%]
test_three.py::test_dict_equal FAILED                                                                                                                                [100%]

================================================ FAILURES ===================================================
___________________________________________ test_task_equality ______________________________________________

    def test_task_equality():
        t1 = Task('sit there', 'brain')
        t2 = Task('do something', 'okken')
        print(t1)
        print(t2)
>       assert t1 == t2
E       AssertionError: assert Task(summary=...alse, id=None) == Task(summary='...alse, id=None)
E         At index 0 diff: 'sit there' != 'do something'
E         Full diff:
E         - Task(summary='sit there', owner='brain', done=False, id=None)
E         ?                ^^^  ^^^          ^^^^
E         + Task(summary='do something', owner='okken', done=False, id=None)
E         ?               +++ ^^^  ^^^          ^^^^

test_three.py:14: AssertionError
----------------------------------------- Captured stdout call -----------------------------------------------
Task(summary='sit there', owner='brain', done=False, id=None)
Task(summary='do something', owner='okken', done=False, id=None)
___________________________________________ test_dict_equal __________________________________________________
    def test_dict_equal():
        t1_dict = Task('make sandwich', 'okken')._asdict()
        t2_dict = Task('make sandwich', 'okkem')._asdict()
        print(t1_dict)
        print(t2_dict)
>       assert t1_dict == t2_dict
E       AssertionError: assert OrderedDict([...('id', None)]) == OrderedDict([(...('id', None)])
E         Omitting 3 identical items, use -vv to show
E         Differing items:
E         {'owner': 'okken'} != {'owner': 'okkem'}
E         Full diff:
E         OrderedDict([('summary', 'make sandwich'),
E         -              ('owner', 'okken'),
E         ?                             ^...
E         
E         ...Full output truncated (5 lines hidden), use '-vv' to show

test_three.py:22: AssertionError
-------------------------------------------- Captured stdout call --------------------------------------------
OrderedDict([('summary', 'make sandwich'), ('owner', 'okken'), ('done', False), ('id', None)])
OrderedDict([('summary', 'make sandwich'), ('owner', 'okkem'), ('done', False), ('id', None)])
========================================== 2 failed in 0.13 seconds ==========================================

預期異常

""" 在Task項目的API中，有幾個地方可能拋出異常 def add(task): # type:(Task) ->int def get(task_id): # type:(int) ->Task def list_tasks(owner=None): # type:(str|None) ->list of task def count(): # type:(None) ->int def update(task_id, task): # type:(int, Task) ->None def delete(task_id): # type:(int) ->None def delete_all(): # type:() ->None def unique_id(): # type:() ->int def start_tasks_db(db_path, db_type): # type:(str, str) ->None def stop_tasks_db(): # type:() ->None """

import pytest
import tasks

def test_add_raises():
    with pytest.raises(TypeError):
        tasks.add(task='no a Task object')

""" 測試用例中有with pytest.raise(TypeError)生命，意味着不管with結構中的內容是什麼 都至少會發生TypeError異常，若是測試經過，說明確實發生了咱們預期TypeError，若是拋出的是其餘類型的異常 則與咱們預期的異常不一致，測試用例執行失敗 """

def test_start_tasks_db_raises():
    with pytest.raises(ValueError) as excinfo:
        tasks.start_tasks_db('some/great/path', 'mysql')
    exception_msg = excinfo.value.args[0]
    assert exception_msg == "db_type must be a 'tiny' or 'mongo' "

測試函數的標記

from collections import namedtuple
import pytest
Task = namedtuple('Task', ['summary','owner','done','id'])
# __new__.__defaults__建立默認的Task對象
Task.__new__.__defaults__ = (None, None, False, None)


@pytest.mark.smoke
def test_task_equality():
    t1 = Task('sit there', 'brain')
    t2 = Task('do something', 'okken')
    print(t1)
    print(t2)
    assert t1 == t2


@pytest.mark.dict
@pytest.mark.smoke
def test_dict_equal():
    t1_dict = Task('make sandwich', 'okken')._asdict()
    t2_dict = Task('make sandwich', 'okkem')._asdict()
    print(t1_dict)
    print(t2_dict)
    assert t1_dict == t2_dict

執行結果以下：ide

E:\Programs\Python\Python_Pytest\TestScripts>pytest -v -m 'smoke' test_five.py
======================================== test session starts =================================================
platform win32 -- Python 3.7.3, pytest-4.5.0, py-1.8.0, pluggy-0.11.0 -- c:\python37\python.exe
cachedir: .pytest_cache
rootdir: E:\Programs\Python\Python_Pytest\TestScripts
plugins: xdist-1.29.0, timeout-1.3.3, repeat-0.8.0, instafail-0.4.1, forked-1.0.2, emoji-0.2.0, allure-pytest-2.6.3
collected 2 items                                                                                                                                                          

test_five.py::test_task_equality FAILED                                                                                                                              [ 50%]
test_five.py::test_dict_equal FAILED                                                                                                                                 [100%]

================================================ FAILURES ====================================================
__________________________________________ test_task_equality ________________________________________________
    @pytest.mark.smoke
    def test_task_equality():
        t1 = Task('sit there', 'brain')
        t2 = Task('do something', 'okken')
        print(t1)
        print(t2)
>       assert t1 == t2
E       AssertionError: assert Task(summary=...alse, id=None) == Task(summary='...alse, id=None)
E         At index 0 diff: 'sit there' != 'do something'
E         Full diff:
E         - Task(summary='sit there', owner='brain', done=False, id=None)
E         ?                ^^^  ^^^          ^^^^
E         + Task(summary='do something', owner='okken', done=False, id=None)
E         ?               +++ ^^^  ^^^          ^^^^

test_five.py:14: AssertionError
--------------------------------------- Captured stdout call -------------------------------------------------
Task(summary='sit there', owner='brain', done=False, id=None)
Task(summary='do something', owner='okken', done=False, id=None)
___________________________________________ test_dict_equal __________________________________________________
    @pytest.mark.dict
    @pytest.mark.smoke
    def test_dict_equal():
        t1_dict = Task('make sandwich', 'okken')._asdict()
        t2_dict = Task('make sandwich', 'okkem')._asdict()
        print(t1_dict)
        print(t2_dict)
>       assert t1_dict == t2_dict
E       AssertionError: assert OrderedDict([...('id', None)]) == OrderedDict([(...('id', None)])
E         Omitting 3 identical items, use -vv to show
E         Differing items:
E         {'owner': 'okken'} != {'owner': 'okkem'}
E         Full diff:
E         OrderedDict([('summary', 'make sandwich'),
E         -              ('owner', 'okken'),
E         ?                             ^...
E         
E         ...Full output truncated (5 lines hidden), use '-vv' to show

test_five.py:24: AssertionError
--------------------------------------- Captured stdout call -------------------------------------------------
OrderedDict([('summary', 'make sandwich'), ('owner', 'okken'), ('done', False), ('id', None)])
OrderedDict([('summary', 'make sandwich'), ('owner', 'okkem'), ('done', False), ('id', None)])
============================================ warnings summary ================================================
c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.smoke - is this a typo?  You can register custom marks to avoi
d this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.dict - is this a typo?  You can register custom marks to avoid
 this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

-- Docs: https://docs.pytest.org/en/latest/warnings.html
=================================== 2 failed, 2 warnings in 0.22 seconds =====================================

在命令行執行使用了 -m marker_name參數，pytest在執行時會自動尋找被標記爲marker_name的測試方法去執行，同時-m還支持and、or、not關鍵字，以下方式：函數

E:\Programs\Python\Python_Pytest\TestScripts>pytest -v -m "smoke and not dict" test_five.py
========================================= test session starts ================================================
platform win32 -- Python 3.7.3, pytest-4.5.0, py-1.8.0, pluggy-0.11.0 -- c:\python37\python.exe
cachedir: .pytest_cache
rootdir: E:\Programs\Python\Python_Pytest\TestScripts
plugins: xdist-1.29.0, timeout-1.3.3, repeat-0.8.0, instafail-0.4.1, forked-1.0.2, emoji-0.2.0, allure-pytest-2.6.3
collected 2 items / 1 deselected / 1 selected                                                                                                                              

test_five.py::test_task_equality FAILED                                                                                                                              [100%]

============================================= FAILURES =======================================================
_______________________________________ test_task_equality ___________________________________________________

    @pytest.mark.smoke
    def test_task_equality():
        t1 = Task('sit there', 'brain')
        t2 = Task('do something', 'okken')
        print(t1)
        print(t2)
>       assert t1 == t2
E       AssertionError: assert Task(summary=...alse, id=None) == Task(summary='...alse, id=None)
E         At index 0 diff: 'sit there' != 'do something'
E         Full diff:
E         - Task(summary='sit there', owner='brain', done=False, id=None)
E         ?                ^^^  ^^^          ^^^^
E         + Task(summary='do something', owner='okken', done=False, id=None)
E         ?               +++ ^^^  ^^^          ^^^^

test_five.py:14: AssertionError
--------------------------------------- Captured stdout call ------------------------------------------------
Task(summary='sit there', owner='brain', done=False, id=None)
Task(summary='do something', owner='okken', done=False, id=None)
========================================= warnings summary ===================================================
c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.smoke - is this a typo?  You can register custom marks to avoi
d this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.dict - is this a typo?  You can register custom marks to avoid
 this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

-- Docs: https://docs.pytest.org/en/latest/warnings.html
============================= 1 failed, 1 deselected, 2 warnings in 0.14 seconds =============================

跳過測試

from collections import namedtuple
import pytest
Task = namedtuple('Task', ['summary','owner','done','id'])
# __new__.__defaults__建立默認的Task對象
Task.__new__.__defaults__ = (None, None, False, None)


@pytest.mark.smoke
def test_task_equality():
    t1 = Task('sit there', 'brain')
    t2 = Task('do something', 'okken')
    print(t1)
    print(t2)
    assert t1 == t2


@pytest.mark.dict
@pytest.mark.smoke
@pytest.mark.skip(reason="跳過緣由你不知道嗎？")
def test_dict_equal():
    t1_dict = Task('make sandwich', 'okken')._asdict()
    t2_dict = Task('make sandwich', 'okkem')._asdict()
    print(t1_dict)
    print(t2_dict)
    assert t1_dict == t2_dict

E:\Programs\Python\Python_Pytest\TestScripts>pytest -v test_five.py
======================================= test session starts ==================================================
platform win32 -- Python 3.7.3, pytest-4.5.0, py-1.8.0, pluggy-0.11.0 -- c:\python37\python.exe
cachedir: .pytest_cache
rootdir: E:\Programs\Python\Python_Pytest\TestScripts
plugins: xdist-1.29.0, timeout-1.3.3, repeat-0.8.0, instafail-0.4.1, forked-1.0.2, emoji-0.2.0, allure-pytest-2.6.3
collected 2 items                                                                                                                                                          

test_five.py::test_task_equality FAILED                                                                                                                              [ 50%]
test_five.py::test_dict_equal SKIPPED                                                                                                                                [100%]

============================================== FAILURES ======================================================
_____________________________________________ test_task_equality _____________________________________________

    @pytest.mark.smoke
    def test_task_equality():
        t1 = Task('sit there', 'brain')
        t2 = Task('do something', 'okken')
        print(t1)
        print(t2)
>       assert t1 == t2
E       AssertionError: assert Task(summary=...alse, id=None) == Task(summary='...alse, id=None)
E         At index 0 diff: 'sit there' != 'do something'
E         Full diff:
E         - Task(summary='sit there', owner='brain', done=False, id=None)
E         ?                ^^^  ^^^          ^^^^
E         + Task(summary='do something', owner='okken', done=False, id=None)
E         ?               +++ ^^^  ^^^          ^^^^

test_five.py:14: AssertionError
--------------------------------------- Captured stdout call -------------------------------------------------
Task(summary='sit there', owner='brain', done=False, id=None)
Task(summary='do something', owner='okken', done=False, id=None)
========================================= warnings summary ===================================================
c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.smoke - is this a typo?  You can register custom marks to avoi
d this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.dict - is this a typo?  You can register custom marks to avoid
 this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

-- Docs: https://docs.pytest.org/en/latest/warnings.html
============================= 1 failed, 1 skipped, 2 warnings in 0.21 seconds ================================

從測試結果中咱們看到，測試用例test_five.py::test_dict_equal SKIPPED 被跳過了，然而跳過緣由並無如期的展現出來，可使用參數-rs來展現跳過緣由，以下方式：測試

E:\Programs\Python\Python_Pytest\TestScripts>pytest -rs test_five.py
==================================== test session starts =====================================================
platform win32 -- Python 3.7.3, pytest-4.5.0, py-1.8.0, pluggy-0.11.0
rootdir: E:\Programs\Python\Python_Pytest\TestScripts
plugins: xdist-1.29.0, timeout-1.3.3, repeat-0.8.0, instafail-0.4.1, forked-1.0.2, emoji-0.2.0, allure-pytest-2.6.3
collected 2 items                                                                                                                                                          

test_five.py Fs                                                                                                                                                      [100%]

========================================== FAILURES ==========================================================
________________________________________ test_task_equality __________________________________________________
    @pytest.mark.smoke
    def test_task_equality():
        t1 = Task('sit there', 'brain')
        t2 = Task('do something', 'okken')
        print(t1)
        print(t2)
>       assert t1 == t2
E       AssertionError: assert Task(summary=...alse, id=None) == Task(summary='...alse, id=None)
E         At index 0 diff: 'sit there' != 'do something'
E         Use -v to get the full diff

test_five.py:14: AssertionError
-------------------------------------------- Captured stdout call --------------------------------------------
Task(summary='sit there', owner='brain', done=False, id=None)
Task(summary='do something', owner='okken', done=False, id=None)
============================================== warnings summary ==============================================
c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.smoke - is this a typo?  You can register custom marks to avoi
d this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

c:\python37\lib\site-packages\_pytest\mark\structures.py:324
  c:\python37\lib\site-packages\_pytest\mark\structures.py:324: PytestUnknownMarkWarning: Unknown pytest.mark.dict - is this a typo?  You can register custom marks to avoid
 this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

-- Docs: https://docs.pytest.org/en/latest/warnings.html
==================================== short test summary info =================================================
SKIPPED [1] test_five.py:17: 跳過緣由你不知道嗎？
============================== 1 failed, 1 skipped, 2 warnings in 0.14 seconds ===============================

還能夠給跳過添加理由，例如當selenium版本是1.0.4的時候跳過this

from collections import namedtuple
import pytest
import selenium
Task = namedtuple('Task', ['summary','owner','done','id'])
# __new__.__defaults__建立默認的Task對象
Task.__new__.__defaults__ = (None, None, False, None)


@pytest.mark.smoke
def test_task_equality():
    t1 = Task('sit there', 'brain')
    t2 = Task('do something', 'okken')
    print(t1)
    print(t2)
    assert t1 == t2


@pytest.mark.dict
@pytest.mark.smoke
@pytest.mark.skipif(selenium.__version__ == '1.0.4', reason="跳過緣由你不知道嗎？")
def test_dict_equal():
    t1_dict = Task('make sandwich', 'okken')._asdict()
    t2_dict = Task('make sandwich', 'okkem')._asdict()
    print(t1_dict)
    print(t2_dict)
    assert t1_dict == t2_dict

運行測試子集

運行單個目錄，只須要將目錄做爲pytest的參數便可
pytest -v test/func --tb=no
運行單個測試函數，只須要在文件名後添加::符號和函數名
pytest -v test/func/test_five.py::test_dict_equal
運行單個測試類，與運行單個測試函數相似,在文件名後添加::符號和類名
pytest -v test/func/test_five.py::Test_Update
運行單個測試類中的測試方法，在文件名後添加::符號和類名而後再跟::符號和函數名
pytest -v test/func/test_five.py::Test_Update::test_dict_equalspa