Testing introduction

Django includes a test framework built on Python's unittest (and pytest-django in many teams). Test models, views, forms, and APIs to catch regressions before deploy.

Test client

from django.test import TestCase, Client

class ArticleTests(TestCase):
    def test_index_returns_200(self):
        response = self.client.get("/")
        self.assertEqual(response.status_code, 200)

What to test

• Model methods and validation
• Forms—valid/invalid data
• Views—status codes, redirects, context
• Permissions—anonymous vs authenticated

Important interview questions and answers

1. Q: Test database?
   A: Django creates a separate test DB—tests can run transactions rolled back per test.
2. Q: fixtures vs factories?
   A: Fixtures are static JSON; factories (factory_boy) generate test data programmatically—factories scale better.
3. Q: Integration vs unit?
   A: Unit tests isolate logic; integration tests hit DB and URL routing—balance speed and confidence.

Self-check

1. What does Django's test Client simulate?
2. Why test permission rules?

Tip: Test permission denials (403/redirect) alongside happy paths—auth bugs are common and cheap to catch with Client tests.