Factory Boy can help you during testing Django Apps

Yanwar Solahudin
Jul 29, 2017 · 2 min read
Image for post
Image for post

During my work with the team, i learned a lot from them. Especially with CTO and my friends there. They taught me by giving a test code that is so beautiful. With Django Factory Boy I can create a shadow object during the testing phase without needing to create objects from the queryset that make it so simple.

This note gives me feedback in the future. I keep using this note for my reference in the code testing phase in Django Framework.

For installation, it’s pretty easy. I only need a package named factory_boy which includes the Faker packages.

(myenv) $ pip install factory_boy

If you want to see full reference from factory_boy, you can visit this .

How to use ?

How to use it is quite easy. In this case I have a simple model class, called Product model.

class Product(models.Model):
sku = models.CharField(max_length=30, unique=True,
name = models.CharField(max_length=30)
base_price = models.PositiveIntegerField()
price = models.PositiveIntegerField()
stock = models.PositiveIntegerField()
stock_min = models.PositiveIntegerField()
def __str__(self):
return self.sku
class Meta:
db_table = 'product'

Then, iwill create a tests directory. However, I need to delete the tests.py file inside my app before making it.

Then I will create a structure like this inside my app:


The factories.py file contains the factory product that will create the product object as long as I call it in the testing phase. It will create as many objects as I want in testing. While the test_products_v1.py file contains the test code for the product.

The contents of the factories.py file are as follows:

import factory
import random
from factory.django import DjangoModelFactory
class ProductFactory(DjangoModelFactory): @factory.sequence
def sku(n):
return 'SKU-%d' % n
def name(n):
return 'PRODUCT-%d' % n
base_price = factory.lazy_attribute(
lambda o: random.randint(100, 2000))
price = factory.lazy_attribute(
lambda o: random.randint(1000, 20000))
stock = factory.lazy_attribute(lambda o: random.randint(1, 100))
stock_min = factory.lazy_attribute(
lambda o: random.randint(1, 5))
class Meta:
model = myapp.Product'

Look at the fields. It’s like a field on a model that’s in the Product model. In the Meta class, there is one attribute named model. This attribute contains a value referencing my Product model that has the format <appname>. <ModelName>.

Ok, if we make the test in the file test_products_v1.py, more or less we will use the Factory class we have created earlier:

import jsonfrom django.test import TestCase
from rest_framework.test import APITestCase
from rest_framework import status
from salesapi.tests.factories import ProductFactoryfrom sales.models import Productclass TestProductsV1(APITestCase): def test_product_list(self): for _ in range(3):
response = self.client.get(
expected = 3 self.assertEqual(
response.status_code, status.HTTP_200_OK)

Simple and so elegant. I love it. Django & Python is fucking awesome.

Welcome to a place where words matter. On Medium, smart voices and original ideas take center stage - with no ads in sight. Watch

Follow all the topics you care about, and we’ll deliver the best stories for you to your homepage and inbox. Explore

Get unlimited access to the best stories on Medium — and support writers while you’re at it. Just $5/month. Upgrade

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store