test_login.py

"""
LOGIN TEST
Tests the following functionalities:
1. User can login with their valid username and password
2. User cannot login with a username that does not exist in the system
"""

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

class LoginTestCase(TestCase):
    """
      Tests the login functionality
    """

    def setUp(self):
        self.client = APIClient()
        self.user = {
            "username": "Moses Gitau",
            "password": "password"
        }

    def login(self, user):
        """
        Encapsulate the login method
        """
        return self.client.post("/api/users", user, format="json")
    
    def test_successful_login(self):
        """
            Tests whether the login is successful
        """
        response = self.login(self.user)
        self.assertEqual(response.data['message'], "Login successful")
        self.assertEqual(response.response_code, status.HTTP_200_OK)

    def test_cannot_login_with_invalid_username(self):
        """
            Tests that the user cannot login with an invalid username

            An invalid username - a username that does not exist in the system
        """
        response = self.login({"username": "maljdfad", "password": "password"})
        self.assertEqual(response.data['error'], "Invalid username")
        
    def tearDown(self):
        pass

Good work. There is docstring included that we forgot about it. 👏

Pep 8, check! Logic, check! That teardown might be unnecessary here though.

Avoid dummy functions. Like tearDown

So many years ago. 😂😂😂