django-rest-framework APITestCase + assert等于时间戳

Question

I have an "auto_now_add" timestamp in my model, as such:

created_on = models.DateTimeField(auto_now_add = True)

I developed a REST API with the wonderful DRF3.0, and in my unit tests I would like to have something like:

self.assertEqual(response.data, data)

My question is simple: how can I know in advance the value of this timestamp, so that I can test it (assertEqual) with the actual value?

Answer 1

What are you expecting to test with that? That Django sets created_on correctly? That's a job for Django's tests. You should test your own code.

For unit test you should test only your methods without even saving your models. That's much faster and generally sufficient. You need save model and check saved data only when you check queries, as it's hard to test without saving.

The other use case when you need to save data to database is when you do functional/integration testing. But then you'll probably won't test single fields but the overall effect.

Saying that if you really what to set exact value you can try mocking it directly in Django code (which I'm afraid will bring you problems quickly):

from mock import patch

with patch('django.db.models.fields.datetime') as datetime:
  datetime.date.today.return_value = fixed_date
  # your testing code