2

Rails 有一个断言,可以在执行块后测试值的差异。从这里

assert_difference 'Article.count', 1 do
  post :create, article: {...}
end  

该断言将执行创建后命令,并测试Article.count在执行该块后是否增加了 1。

Python 或 Django 中是否有类似的断言?如果不是,最有效的实现是否只是存储数字,然后再获取它?

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1 回答 1

3

显式优于隐式

这基本上做同样的事情。

pre_count = Article.objects.count()

# Your Logic

post_count = Article.objects.count()

self.assertEqual(post_count-pre_count, 1)

或者,对于那种额外的红宝石调味剂,

from django.utils.decorators import method_decorator
from contextlib import contextmanager

def ExtendedTestCase(TestCase):

    @method_decorator(context_manager)
    def assertDifference(self, func, diff, message=None):
        " A Context Manager that performs an assert. "
        old_value = func()
        yield # `with` statement runs here. Roughly equivalent to ruby's blocks
        new_value = func()
        self.assertEqual(new_value-old_value, diff, message)

def ArticleTestCase(ExtendedTestCase):

    def test_article_creation(self):
        " Test that new articles can be created "
        with self.assertDifference(Article.count, 1):
             self.client.post("/article/new/", {
                 "title": "My First Django Article",
                 "content": "Boring Technical Content",
             })
于 2013-07-29T07:58:28.520 回答