Testing

Powered by Pytest. Used for surgically poking the application to verify desired responses.

Properties: Pytest files

./pytest.ini
./apps/conftest.py

Properties: VSCode shortcuts

Ctrl + R: Refresh tests
Ctrl + S: Run all
Ctrl + E: Run at cursor
Ctrl + Tab: Debug last
`Ctrl + ``: Debug at cursor

Properties: Pytest plugins

pytest-django: the man.
pytest-playwright
pytest-base-url
pytest-cov
pytest-env
pytest-factoryboy
pytest-redis
pytest-xdist

Testing `utils.py`

Provide input to utility functions, verify if output corresponds with expectations.

Workflow: Writing a test for a utility function

Create ./apps/my_app/tests/test_utils.py, load pytest-django plugin:
```
import pytest
pytestmark = [pytest.mark.django_db]
```

Import the utility function:

from apps.my_app.utils import my_utility_function

Define the test function with a clear name. Load setup fixtures if needed:
```
def test_my_utility_function_returns_expected_value():
```

Define input data and call the function:

    input_data = "example"
    result = my_utility_function(input_data)

Assert that the output matches expectations:
```
    assert result == "expected_output"
```

Fixtures

Function to get reusable context for tests.

Workflow: Create customizable fixture to setup test context

Create base fixture

@pytest.fixture
def create_author(request):
    Author.objects.create(name=f'Author 1')

Identify the need of customization.

Customize to meet the need:

@pytest.fixture
def create_author(request):
    params = getattr(request, 'param', {})
    if 'author_count' in params:
        for i in range(params['author_count']):
            Author.objects.create(name=f'Author {i}')
    return client
    
@pytest.mark.parametrize('create_author', [{'author_count': 3}], indirect=True)
def test_create_many_authors(create_author):
    ...

Definition: client fixture with logged in `TestClient`

Always logged in client

from django.contrib.auth.models import User

@pytest.fixture
def client(client):
    username='testuser'
    password='testpassword123'
    user = User.objects.create_user(
        username=username,
        password=password
    )
    client.login(
        username=username,
        password=password
    )
    return client