尝试运行pytest-django时显示“应用尚未加载”

Question

以Django教程中的（部分）民意调查应用为例，我试图让pytest-django运行。

使用命令django-admin startproject mysite2，我创建了一个具有以下结构的项目目录：

.
??? db.sqlite3
??? manage.py
??? mysite2
?   ??? __init__.py
?   ??? settings.py
?   ??? urls.py
?   ??? wsgi.py
??? polls
?   ??? __init__.py
?   ??? admin.py
?   ??? apps.py
?   ??? migrations
?   ?   ??? 0001_initial.py
?   ?   ??? __init__.py
?   ??? models.py
?   ??? tests.py
?   ??? urls.py
?   ??? views.py
??? pytest.ini

我的pytest.ini样子

[pytest]
DJANGO_SETTINGS_MODULE = mysite2.settings
python_files = tests.py test_*.py *_tests.py

按照该教程，polls/models.py我已经创建Question并Choice建模：

import datetime

from django.db import models
from django.utils import timezone

class Question(models.Model):
    question_text = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')

    def __str__(self):
        return self.question_text

    def was_published_recently(self):
        return self.pub_date >= timezone.now() - datetime.timedelta(days=1)

class Choice(models.Model):
    question = models.ForeignKey(Question, on_delete=models.CASCADE)
    choice_text = models.CharField(max_length=200)
    votes = models.IntegerField(default=0)

    def __str__(self):
        return self.choice_text

现在，如果我tests.py按照本教程中的说明进行操作（该教程基于Python的内置unittest模块），

import datetime

from django.utils import timezone
from django.test import TestCase

from .models import Question

class QuestionModelTests(TestCase):
    def test_was_published_recently_with_future_question(self):
        time = timezone.now() + datetime.timedelta(days=30)
        future_question = Question(pub_date=time)
        self.assertIs(future_question.was_published_recently(), False)

并且我从命令行运行python manage.py test，则测试失败了：

Creating test database for alias 'default'...
System check identified no issues (0 silenced).
F
======================================================================
FAIL: test_was_published_recently_with_future_question (polls.tests.QuestionModelTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/kurtpeek/Documents/Scratch/mysite2/polls/tests.py", line 23, in test_was_published_recently_with_future_question
    self.assertIs(future_question.was_published_recently(), False)
AssertionError: True is not False

----------------------------------------------------------------------
Ran 1 test in 0.001s

FAILED (failures=1)
Destroying test database for alias 'default'...

但是，如果我将测试代码更改为（尝试的）pytest等效代码（也就是说，无需子类化TestCase且具有普通的断言）：

def test_was_published_recently_with_future_question():
    time = timezone.now() + datetime.timedelta(days=30)
    future_question = Question(pub_date=time)
    assert future_question.was_published_recently() is False

并运行pytest命令，我得到以下错误：

================================= test session starts ==================================
platform darwin -- Python 3.6.3, pytest-3.2.3, py-1.4.34, pluggy-0.4.0
rootdir: /Users/kurtpeek/Documents/Scratch/mysite2, inifile: pytest.ini
plugins: timeout-1.2.1
collected 0 items / 1 errors                                                            

======================================== ERRORS ========================================
___________________________ ERROR collecting polls/tests.py ____________________________
polls/tests.py:10: in <module>
    from .models import Question
polls/models.py:6: in <module>
    class Question(models.Model):
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/base.py:100: in __new__
    app_config = apps.get_containing_app_config(module)
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/apps/registry.py:244: in get_containing_app_config
    self.check_apps_ready()
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/apps/registry.py:127: in check_apps_ready
    raise AppRegistryNotReady("Apps aren't loaded yet.")
E   django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet.
!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!!!!!
=============================== 1 error in 0.64 seconds ================================

到目前为止，我还没有找到解决此问题的方法。关于如何运行测试的任何想法？

Answer 1

pytest当使用或调用测试时，我遇到了类似的问题python setup.py test。

对于在我的虚拟环境中pytest安装的调用pytest-django解决了问题。

添加python setup.py install到解决它的pytest-django论点。tests_requiresetup()

这是以下的片段setup.py：

TEST_REQUIREMENTS = [
    'pytest',
    'pytest-django',
    'pylint',
    'pylint_django',
    'git-pylint-commit-hook',
]

setup(
    name='foo',
    version='0.0.1',
    description='Foo package',
    author='...',
    author_email='...',
    packages=['foo'],
    install_requires=INSTALL_REQUIREMENTS,
    setup_requires=SETUP_REQUIREMENTS,
    tests_require=TEST_REQUIREMENTS,
)

Answer 2

开箱pytest即用，即使pytest-django已安装，也不知道Django数据库。不过，请不要担心：pytest-django使用django_db pytest mark可以使您的测试轻松访问Django数据库。

试试看：

import pytest


@pytest.mark.django_db
def test_was_published_recently_with_future_question():
    time = timezone.now() + datetime.timedelta(days=30)
    future_question = Question(pub_date=time)
    assert future_question.was_published_recently() is False

Answer 3

根据Django: AppRegistryNotReady()，不使用时manage.py必须显式调用django.setup()。我通过pytest从manage.pyshell 运行测试来验证这一点：

Kurts-MacBook-Pro:mysite2 kurtpeek$ python3 manage.py shell
Python 3.6.3 (v3.6.3:2c5fed86e0, Oct  3 2017, 00:32:08) 
Type 'copyright', 'credits' or 'license' for more information
IPython 6.2.1 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import pytest

In [2]: pytest.main('polls/tests.py')
================================= test session starts ==================================
platform darwin -- Python 3.6.3, pytest-3.2.3, py-1.4.34, pluggy-0.4.0
rootdir: /Users/kurtpeek/Documents/Scratch/mysite2, inifile: pytest.ini
plugins: timeout-1.2.1
collected 1 item                                                                        

polls/tests.py F

======================================= FAILURES =======================================
___________________ test_was_published_recently_with_future_question ___________________

    def test_was_published_recently_with_future_question():
        time = timezone.now() + datetime.timedelta(days=30)
        future_question = Question(pub_date=time)
>       assert future_question.was_published_recently() is False
E    assert True is False
E     +  where True = <bound method Question.was_published_recently of <Question: >>()
E     +    where <bound method Question.was_published_recently of <Question: >> = <Question: >.was_published_recently

polls/tests.py:18: AssertionError
=================================== warnings summary ===================================
None
  passing a string to pytest.main() is deprecated, pass a list of arguments instead.

-- Docs: http://doc.pytest.org/en/latest/warnings.html
========================= 1 failed, 1 warnings in 0.14 seconds =========================
Out[2]: 1

然而，这实际上并不是一个可接受的解决方案，因为测试需要从命令行运行。是否还有其他pytest装饰器来确保所需的设置？