Celery only gives instructions on how to write integration tests using pyTest not the god ol' python UnitTest framework. So I wrote a CeleryTestCase which can be used as a base class for your integration tests using a real celery worker in the background.

CeleryTestCase.py

from unittest import TestCase
from celery.contrib.testing import worker


class CeleryTestCase(TestCase):
    @property
    def celery_app(self):
        """
            Override this method to provide this testcase with the celery app under test
        """
        raise NotImplementedError()

    def run(self, result=None):
        from kombu.asynchronous.hub import set_event_loop

        set_event_loop(None)
        self.celery_app.loader.import_module('celery.contrib.testing.tasks')

        with worker.start_worker(self.celery_app, loglevel="debug"):
            super(CeleryTestCase, self).run(result)

CodeUnderTest.py

from celery import Celery

celery_app = Celery("CeleryUnderTest", broker='redis://localhost:6379/0', backend='redis://localhost:6379/0')


@celery_app.task
def mul(x, y):
    return x * y

MyTestCase.py

from .CodeUnderTest import celery_app, mul
from .CeleryTestCase import CeleryTestCase


class MyTestCase(CeleryTestCase):
    @property
    def celery_app(self):
        return celery_app

    def test_mul(self):
        self.assertEqual(mul.delay(4, 4).get(timeout=10), 16)

If you getting django.db.utils.InterfaceError: connection already closed change class CeleryTestCase(TestCase): to class CeleryTestCase(TransactionTestCase):

Worked for me