Allauth user_logged_in signal does not trigger in a TestCase

Question

I'm using allauth for user management in my Django web app and I have functionality which finds session data stored when the user was not logged in and stores it when they next log in on the same session.

It is triggered on login via the standard allauth signal:

@receiver(user_logged_in)
def update_on_login(request, user, **kwargs):
    print('Signal triggered')
    # Do some stuff with session data here, e.g.:
    for session_key in request.session.items():
        ...

This works perfectly when logging in via a web browser, but in TestCase functions the signal is not triggered at all when logging in with:

self.client = Client()
logged_in = self.client.login(username=self.username, password=self.password)

(I've also tried force_login and force_authenticate, but info on these indicates that they actually skip all real validation and just assume the user is logged in).

I think I've understood that client.login doesn't work because the test client doesn't really handle the request in the same way as a web browser would, but I can't say I really understand it.

I've also seen some indication that RequestFactory might be able to help in someway, but I haven't been able to trigger the signal with this either:

request = RequestFactory().post(reverse('account_login'), { 'username': self.username, 'password': self.password })
request.user = AnonymousUser()
response = login(request)

I've seen some comments about needing to call middleware as well, but pretty out of date and nothing clear enough for me to understand and try.

Any suggestions to point me in the right direction would be much appreciated. Thanks in advance.