Doc test example may lead to programmer errors

[Lorin Hochstein]

On the ​Testing Django applications page, the initial example subclasses from unittest.TestCase instead of django.test.TestCase.

Although there is some warning text beneath the example about the need to subclass from django.test.TestCase when hitting the database, it's likely that a Django programmer searching for a quick reference on how to structure a test class will treat this as a canonical example and miss the warning text below. (I know at least one person who this has happened to).

I believe it would minimize programmer error to use django.test.TestCase and to have the accompanying test discuss how you can use unittest.TestCase as an optimization when the test doesn't hit the database (as in the example).

I submitted a ​pull request but it was closed, referencing #15896, which is a slightly different issue. I also started a ​django-developers thread about this.

[Aymeric Augustin]

What is the difference with #15896?

[Tim Graham]

This idea makes sense, but I think the example should be modified to actually require the database.

[Lorin Hochstein]

Replying to aaugustin:

What is the difference with #15896?

My understanding is that #15896 was based on a misunderstanding about the difference between django.utils.unittest.TestCase and django.test.TestCase, and so the author claimed (incorrectly) that there was a bug in the test example.

I'm suggesting that the test example, while technically correct, could be improved in a way that would reduce the likelihood of future programmer errors.

[Lorin Hochstein]

Replying to timo:

This idea makes sense, but I think the example should be modified to actually require the database.

Sounds good to me. I'd be happy to make the change. Would it be better to open a new pull request or modify the existing (closed) one?

[Lorin Hochstein]

The original ticket description had an incorrect link for the django-dev discussion, it's ​https://groups.google.com/d/topic/django-developers/xSWH2QYS4cE/discussion

[Tim Graham]

Regarding the pull request, I think either way is fine.

[Lorin Hochstein]

New pull request: ​https://github.com/django/django/pull/1006

[Tim Graham <timograham@…>]

In 84d8b247d20aafb376368dc458f277ad2cd71ecd:

Fixed #20165 - Updated testing example to use django.test.TestCase.

Thanks Lorin Hochstein.

[Tim Graham <timograham@…>]

In 7f4269229cd6ca0ef94a34fd045e3ced9bdd57d0:

[1.5.x] Fixed #20165 - Updated testing example to use django.test.TestCase.

Thanks Lorin Hochstein.

Backport of 84d8b247d2 from master.