Example Python test

test_login.py

from unittest import TestCase
from rest_framework import status
from rest_framework.test import APIClient


class BaseTestCase(TestCase):
    def setUp(self):
        self.client = APIClient()

    def post_login(self, username='johndoe', password='P@$$word'):
        return self.client.post('/api/auth/login', {'username': username, 'password': password})


class TestLogin(BaseTestCase):
    def test_successful_login(self):
        response = self.post_login()
        self.assertEqual(response.status, status.HTTP_200_OK)

    def test_missing_username_is_not_allowed(self):
        response = self.post_login(username='')
        self.assertEqual(response.status, status.HTTP_422_UNPROCESSABLE_ENTITY)
        self.assertIn(response.data['errors'], 'An username is required to log in.')

    def test_missing_password_is_not_allowed(self):
        response = self.post_login(password='')
        self.assertEqual(response.status, status.HTTP_422_UNPROCESSABLE_ENTITY)
        self.assertIn(response.data['errors'], 'A password is required to log in.')

    def test_username_with_special_chars_is_not_allowed(self):
        response = self.post_login(username='u$ern@me')
        self.assertIn(response.data['errors'], 'Special characters are not allowed on the username.')

This was thorough and well thought.