python – 具有模拟数据的ModelChoiceField的UnitTest ModelForm

这是我的模特：

# models.py
class Menu(models.Model):
    dish = models.ForeignKey(Dish,default=None)
    price = models.DecimalField(max_digits=7,decimal_places=2)

# forms.py
class MenuForm(forms.ModelForm):
    class Meta:
        model = Menu
        fields = ('dish','price',)

    def clean(self):
        cleaned_data = super(MenuForm,self).clean()
        price = cleaned_data.get('price',None)
        dish = cleaned_data.get('dish',None)

        # Some validation below
        if price < 70:
            self.add_error('price','Min price threshold')
            return cleaned_data

这是我的测试用例：

class MenuFormTest(TestCase):
    def test_price_threshold(self):
        mock_dish = mock.Mock(spec=Dish)
        form_data = {
            'dish': mock_dish,'price': 80,}
        form = forms.MenuForm(data=form_data)
        self.assertTrue(form.is_valid())

此操作失败,并显示以下错误：

<ul class="errorlist"><li>dish<ul class="errorlist"><li>Select a valid choice. That choice is not one of the available choices.</li></ul></li></ul>

如何避免抛出该错误. form.is_valid()应该是True.有没有办法可以修补ModelChoiceField的查询集？我试着修补form的dish field clean()方法,如下所示：

form = forms.MenuForm(data=form_data)
dish_clean_patcher = mock.patch.object(form.fields['dish'],'clean')
dish_clean_patch = dish_clean_patcher.start()
dish_clean_patch.return_value = mock_dish

self.assertTrue(form.is_valid())

然后看起来,它在将表单数据保存到_post_clean()方法中的模型实例时失败了.这是追溯：

Traceback (most recent call last):
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/mock/mock.py",line 1305,in patched
    return func(*args,**keywargs)
  File "/vagrant/myapp/tests/test_forms.py",line 51,in test_price_threshold
    self.assertFalse(form.is_valid())
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/forms/forms.py",line 185,in is_valid
    return self.is_bound and not self.errors
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/forms/forms.py",line 177,in errors
    self.full_clean()
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/forms/forms.py",line 396,in full_clean
    self._post_clean()
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/forms/models.py",line 427,in _post_clean
    self.instance = construct_instance(self,self.instance,opts.fields,construct_instance_exclude)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/forms/models.py",line 62,in construct_instance
    f.save_form_data(instance,cleaned_data[f.name])
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/db/models/fields/__init__.py",line 874,in save_form_data
    setattr(instance,self.name,data)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/db/models/fields/related.py",line 632,in __set__
    instance._state.db = router.db_for_write(instance.__class__,instance=value)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/django/db/utils.py",line 300,in _route_db
    if instance is not None and instance._state.db:
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/mock/mock.py",line 716,in __getattr__
    raise AttributeError("Mock object has no attribute %r" % name)
AttributeError: Mock object has no attribute '_state'

我该如何避免这一部分？我根本不想查看instance._state.db.

我正确测试表格吗？或者我应该而不是调用form.is_valid(),只需调用form.clean()方法,完全修补super(MenuForm,self).clean()方法,并检查form.errors？