Automated API Tests0%
Automated API Tests
Beginner12 min read•Updated: Jul 11, 2026
Automated API Integration Tests and Model Factories
As test suites grow from tens to hundreds of test cases, manual Model.objects.create(...) calls result in fragile, verbose, and difficult-to-maintain test setups. Using factory_boy and faker provides clean, dynamic mock fixtures, while end-to-end integration tests verify complete business workflows.
1. Setting Up factory_boy for DRF Models
factory_boy generates realistic model instances with foreign keys, default attributes, and sequence counters.
Bash / Terminal
pip install factory_boy faker
Create store/factories.py:
Python
import factory
from django.contrib.auth import get_user_model
from store.models import Category, Product, Order, OrderItem
User = get_user_model()
class UserFactory(factory.django.DjangoModelFactory):
class Meta:
model = User
username = factory.Faker('user_name')
email = factory.Faker('email')
first_name = factory.Faker('first_name')
last_name = factory.Faker('last_name')
class CategoryFactory(factory.django.DjangoModelFactory):
class Meta:
model = Category
name = factory.Sequence(lambda n: f'Category {n}')
slug = factory.Sequence(lambda n: f'category-{n}')
class ProductFactory(factory.django.DjangoModelFactory):
class Meta:
model = Product
category = factory.SubFactory(CategoryFactory)
title = factory.Faker('catch_phrase')
sku = factory.Sequence(lambda n: f'SKU-{n:05d}')
price = factory.Faker('pydecimal', left_digits=3, right_digits=2, positive=True)
inventory = 50
2. Using Factories in API Integration Tests
Notice how concise and expressive test setup becomes:
Python
from rest_framework.test import APITestCase
from rest_framework import status
from store.factories import UserFactory, ProductFactory, CategoryFactory
class ProductSearchIntegrationTests(APITestCase):
def setUp(self):
self.user = UserFactory()
self.cat_laptops = CategoryFactory(name='Laptops')
self.cat_audio = CategoryFactory(name='Audio')
# Batch create products
self.macbook = ProductFactory(category=self.cat_laptops, title='Apple MacBook Pro 16')
self.dell = ProductFactory(category=self.cat_laptops, title='Dell XPS 15')
self.headphones = ProductFactory(category=self.cat_audio, title='Sony WH-1000XM5 Headphones')
def test_filter_by_category_returns_matching_products(self):
response = self.client.get('/api/v1/products/', {'category': self.cat_laptops.id})
self.assertEqual(response.status_code, status.HTTP_200_OK)
self.assertEqual(response.data['count'], 2)
titles = [p['title'] for p in response.data['results']]
self.assertIn('Apple MacBook Pro 16', titles)
self.assertIn('Dell XPS 15', titles)
self.assertNotIn('Sony WH-1000XM5 Headphones', titles)
3. End-to-End Workflow Testing: Order Checkout
Integration tests should test multi-step workflows representing real client interactions:
Python
class CheckoutWorkflowTests(APITestCase):
def setUp(self):
self.customer = UserFactory()
self.product = ProductFactory(price=100.00, inventory=10)
def test_complete_checkout_workflow(self):
self.client.force_authenticate(user=self.customer)
# Step 1: Create Cart
cart_res = self.client.post('/api/v1/carts/', format='json')
self.assertEqual(cart_res.status_code, status.HTTP_201_CREATED)
cart_id = cart_res.data['id']
# Step 2: Add item to cart
item_res = self.client.post(
f'/api/v1/carts/{cart_id}/items/',
{'product': self.product.id, 'quantity': 2},
format='json'
)
self.assertEqual(item_res.status_code, status.HTTP_201_CREATED)
# Step 3: Checkout order
checkout_res = self.client.post(
'/api/v1/orders/',
{'cart_id': cart_id, 'shipping_address': '123 Tech Lane, San Francisco, CA'},
format='json'
)
self.assertEqual(checkout_res.status_code, status.HTTP_201_CREATED)
self.assertEqual(checkout_res.data['total_price'], '200.00')
# Step 4: Verify stock deduction
self.product.refresh_from_db()
self.assertEqual(self.product.inventory, 8)
Interactive Quiz
Practice Quiz
Question 1
What primary benefit does
factory_boy provide in Django test suites?Question 2
What is
factory.SubFactory() used for in factory_boy?Question 3
How does
factory.Sequence() prevent database uniqueness constraint collisions?Question 4
What distinguishes an integration test from an isolated unit test in DRF?
Question 5
In an end-to-end order placement test, why must
product.refresh_from_db() be called?Next Lesson
Swagger UI Integration
Continue learning with hands-on practice, examples, and exercises in the upcoming topic.
Related Lessons
| Previous Lesson | Next Lesson |
|---|---|
| Using Django Test Client | Swagger UI Integration |
Practice Quiz
Test your understanding of this lesson with 5 questions. Each question has one correct answer.