Send-email testing with mail.outbox

I’ve written this simple test:

@when('asking for review and saving')
def act(self):
    site = Site(domain='http://127.0.0.1:8000', name='127.0.0.1')
    site.save()

    request = {'SITE_ID': site.id}
    self.asking_reservation = {'reservation_id': self.reservation1.id}
    self.deserialized_data = AskForReviewSerializer(
        data=self.asking_reservation, context={'request': request})


@then('validate data and send email for review asking')
def test(self):
    with freeze_time(self.reservation_creation_date_plus_two_months):
        assert self.deserialized_data.is_valid() == True
        assert len(mail.outbox) == 0

        self.deserialized_data.save()
        assert len(mail.outbox) == 1

And this is the serializer I’m testing which sends an email when saving:

class AskForReviewSerializer(serializers.Serializer):
    reservation_id = serializers.IntegerField()

    def save(self, *args, **kwargs):
        request = self.context.get('request')

        current_site = get_current_site(request)
        reservation_id = self.validated_data['reservation_id']

        reservation = models.Reservation.objects.get(pk=reservation_id)
        if not reservation.is_reviewable:
            raise serializers.ValidationError('This reservation is not reviewable')

        user = reservation.user

        path = f'/reservations/{reservation_id}/review'
        url = settings.BASE_URL + path
        context = {'current_site': current_site,
                   'user': user,
                   'review_url': url,
                   'request': request}

        get_adapter().send_mail(
            'review/email/ask_for_review',
            user.email,
            context)

    class Meta:
        fields = ('reservation_id', )

But mail.outbox is never affected when running the tests, its length is always zero (I ensured that my EMAIL_BACKEND = ‘django.core.mail.backends.locmem.EmailBackend’)

Full test: https://github.com/coretabs/dorm-portal/blob/master/features/steps/reviews.py#L117

Any idea how can I test the email sending behavior using behave-django?

[bittner]

I searched a bit and I realized that BehaviorDrivenTestCase inherits from the StaticLiveServerTestCase which eventually inherits from TestCase

That is correct. That’s why you should use context.test.client if you want to access the Django TestCase that is launched by behave-django. Then the mail.outbox behavior should match what is described in the Django docs you quote…

Is there any workaround to get the mail.outbox populated during the test? or should I rely on the fact the serializer doesn’t throw any exception and keep it as it is?

I believe, there is a conceptual misunderstanding you’re trapped in. You should understand the way behave works (because behave-django is just marrying behave with Django), and how this affects writing tests for DRF, which you’re obviously using. Maybe you could take a look at similar issues (such as #46) and do some research on how writing tests with DRF in combination with behave. I just found out there is a dedicated project called behave-restful, maybe that makes your job easier? Not sure though.

[bittner]

I’m not exactly sure what would be the shortest way to helping you, but at first sight I see a few issues with your code:

1. Your step implementation should have a first argument called context. In your code this is always self. While this is not strictly a technical problem it may obscure the way to find a solution yourself. – Use context as the first argument, the steps are functions not methods (see examples in the project repo).
2. I’m not sure what you’re doing with Site. Can’t you use Django’s test client, which saves you from hard-coding URL values and such?
3. You’re importing mail at the top of the module, I think that’s wrong. You should access the mail object that the Django test client has access to. It sounds obvious that otherwise the object is never populated.
4. Instead of manually creating a client instance and URLs you should be able to move some of the code into the behave setup code and call context.get_url(...).

I like the way you call your step implementation functions (act, test), though! 👍