django - 测试何时引发 ValidationError

Question

我是编程和 Django 的新手。我正在尝试测试我的功能之一以确保引发验证错误。测试确认出现了错误，但也表示测试失败。这怎么可能？

**models.py**
def check_user_words(sender, instance, **kwargs):
    for field in instance._meta.get_fields():
        #field_name = getattr(instance, field.attname)
        if (isinstance(field, models.CharField) and
            contains_bad_words(getattr(instance, field.attname))):
            raise ValidationError("We don't use words like '{}' around here!".format(getattr(instance, field.attname)))

#tests.py
from __future__ import unicode_literals
import datetime
from django.test import TestCase
from django.utils import timezone
from django.test import TestCase
from django.urls import reverse
from .models import Question, Choice, contains_bad_words, check_user_words
from django.core.exceptions import ValidationError


def create_question(question_text, days):
    time = timezone.now() + datetime.timedelta(days=days)
    return Question.objects.create(question_text=question_text, pub_date=time)


class ContainsBadWordsTests(TestCase):
    def test_check_user_words(self):
    question = create_question(question_text="What a minute bucko", days=1)
    with self.assertRaises(ValidationError):
        check_user_words(question)
        question.full_clean()

#after running python manage.py test polls
......
raise ValidationError("We don't use words like '{}' around here!".format(getattr(instance, field.attname)))
ValidationError: [u"We don't use words like 'What a minute bucko' around here!"]

models.py 我如何导入

from __future__ import unicode_literals .... (and others)

filepath = "polls/static/polls/blacklist.yaml"
config = yaml_loader(filepath)
blacklist = [word.lower() for word in config['blacklist']]

def contains_bad_words(user_input_txt):
""" remove punctuation from text
    and make it case-insensitive"""
    user_typ = user_input_txt.encode()
    translate_table = maketrans(string.punctuation, 32 * " ")
    words = user_typ.translate(translate_table).lower().split()
    for bad_word in blacklist:
        for word in words:
            if word == bad_word:
                return True
    return False

@receiver(pre_save)
def check_user_words(sender, instance, **kwargs):
    for field in instance._meta.get_fields():
        if (isinstance(field, models.CharField) and
            contains_bad_words(getattr(instance, field.attname))):
        raise ValidationError("We don't use words like '{}' around here!".format(getattr(instance, field.attname))) 

Answer 1

我们需要查看更多您的代码(特别是 create_question() 以及 check_user_words 如何连接到信号)才能确定，但​​我认为问题在于您正在使用 post_save 信号处理程序来执行 check_user_words()。

如果是这种情况，那么您的测试失败的原因是 create_question() 会导致 post_save 信号触发，而 check_user_words() 将立即执行 - 即 在 with self.assertRaises 上下文之前，因此您的测试失败。

如果是这种情况，那么试试这个:

def test_check_user_words(self):
    with self.assertRaises(ValidationError):
        create_question(question_text="What a minute bucko", days=1)

这个测试现在应该通过了，因为一旦你尝试创建问题就会抛出验证错误。

但是请注意，在信号中执行此操作会在尝试保存对象时导致未捕获的异常。根据您的用例，您最好在模型本身 ( see docs here ) 的 clean() 方法中执行此操作，因为这会导致在模型表单上报告适当的错误等:

def clean(self):
    for field in instance._meta.get_fields():    
        if (isinstance(field, models.CharField) and contains_bad_words(getattr(instance, field.attname))):
            raise ValidationError("We don't use words like '{}' around here!".format(getattr(instance, field.attname)))

(然后放下您的信号处理程序)。然后你可以测试这个:

q = create_question(question_text="What a minute bucko", days=1)
with self.assertRaises(ValidationError):
    q.clean()