How can I call a custom Django manage.py command directly from a test driver?

Question

I want to write a unit test for a Django manage.py command that does a backend operation on a database table. How would I invoke the management command directly from code?

Answer 1

Building on Nate's answer I have this:

def make_test_wrapper_for(command_module):
    def _run_cmd_with(*args):
        """Run the possibly_add_alert command with the supplied arguments"""
        cmd = command_module.Command()
        (opts, args) = OptionParser(option_list=cmd.option_list).parse_args(list(args))
        cmd.handle(*args, **vars(opts))
    return _run_cmd_with

Usage:

from myapp.management import mycommand
cmd_runner = make_test_wrapper_for(mycommand)
cmd_runner("foo", "bar")

The advantage here being that if you've used additional options and OptParse, this will sort the out for you. It isn't quite perfect - and it doesn't pipe outputs yet - but it will use the test database. You can then test for database effects.

I am sure use of Micheal Foords mock module and also rewiring stdout for the duration of a test would mean you could get some more out of this technique too - test the output, exit conditions etc.