Testing Django with pytest

pip install pytest pytest-django

# pytest.ini or pyproject.toml
[pytest]
DJANGO_SETTINGS_MODULE = mysite.settings

# conftest.py
import pytest
from django.contrib.auth.models import User
from tasks.models import Task, Project

@pytest.fixture
def user(db):
    return User.objects.create_user(username='testuser', password='testpass')

@pytest.fixture
def project(db):
    return Project.objects.create(name='Test Project')

@pytest.fixture
def task(db, user, project):
    return Task.objects.create(
        title='Test Task',
        owner=user,
        project=project,
        status='todo',
    )

# tasks/tests/test_models.py
import pytest
from tasks.models import Task

@pytest.mark.django_db
def test_task_creation(user, project):
    task = Task.objects.create(title='Test', owner=user, project=project)
    assert task.title == 'Test'
    assert task.status == 'todo'
    assert str(task) == 'Test'

@pytest.mark.django_db
def test_task_complete(task):
    task.status = 'done'
    task.save()
    assert Task.objects.get(pk=task.pk).status == 'done'

# tasks/tests/test_views.py
import pytest
from django.test import Client
from django.urls import reverse

@pytest.mark.django_db
def test_task_list_requires_login(client):
    response = client.get(reverse('task-list'))
    assert response.status_code == 302  # redirect to login

@pytest.mark.django_db
def test_task_list_authenticated(client, user, task):
    client.login(username='testuser', password='testpass')
    response = client.get(reverse('task-list'))
    assert response.status_code == 200
    assert task.title.encode() in response.content

@pytest.mark.django_db
def test_cannot_edit_others_task(client, task):
    other = User.objects.create_user(username='other', password='pass')
    client.login(username='other', password='pass')

    response = client.post(
        reverse('task-edit', kwargs={'pk': task.pk}),
        {'title': 'Hacked!'}
    )
    assert response.status_code in [403, 404]
    task.refresh_from_db()
    assert task.title != 'Hacked!'

pytest                          # run all tests
pytest tasks/                   # tests for a specific application
pytest -v                       # verbose output
pytest -k "test_task"           # filter by name
pytest --cov=tasks              # with coverage report