Enable optional auto-reloading for testserver

[Igor Bakutin]

django/core/management/commands/testserver.py:39 has the following comment

# Run the development server. Turn off auto-reloading because it causes
# a strange error -- it causes this handle() method to be called
# multiple times.

The task is to fix the issue and add optional --autoreload flag to the command

[Mariusz Felisiak]

Thanks for the ticket.

Replying to Igor Bakutin:

django/core/management/commands/testserver.py:39 has the following comment

# Run the development server. Turn off auto-reloading because it causes
# a strange error -- it causes this handle() method to be called
# multiple times.

However, this comment was added in 9c55bbdef7f1717aa17f7ca17cb2396522426310 and that doesn't mean that 14 years later it's still a desirable feature. testserver is intended to work with a database snapshot (loaded from fixtures) so it can be really fragile for any changes in models or migrations. I'm not sure if we can support it in a bulletproof way 🤔.

[Carlton Gibson]

I too think this is probably a mistake to add. (If anything deprecating the testserver command would be the way to go, rather than adding surface area here.) If folks want autoreloading runserver should be sufficient.