pytest-django for Django testing - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the pytest module for Django testing.

PyTest

import [1]

Drag options to blanks, or click blank then click option'

Aunittest

Bpytest

Cdjango

Drequests

Attempts:

3 left

💡 Hint

Common Mistakes

Importing 'django' instead of 'pytest'.

Using 'unittest' which is a different testing framework.

We use import pytest to write tests with pytest and pytest-django.

2fill in blank

medium

Complete the code to mark a test function to use the Django database.

PyTest

@pytest.mark.[1]
def test_create_user(db):
    from django.contrib.auth.models import User
    user = User.objects.create(username='testuser')
    assert user.username == 'testuser'

Drag options to blanks, or click blank then click option'

Askip

Bslow

Cdjango_db

Dxfail

Attempts:

3 left

💡 Hint

Common Mistakes

Using '@pytest.mark.skip' which skips the test.

Using '@pytest.mark.slow' which is unrelated.

The @pytest.mark.django_db decorator allows the test to access the Django database.

3fill in blank

hard

Fix the error in the test function to correctly use the Django test client fixture.

PyTest

def test_homepage([1]):
    response = client.get('/')
    assert response.status_code == 200

Drag options to blanks, or click blank then click option'

Aclient

Bdb

Crequest

Dsettings

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to add 'client' as a parameter.

Using 'db' which is for database access, not client.

The client fixture provides the Django test client for making requests in tests.

4fill in blank

hard

Fill both blanks to create a test that checks if a Django model instance is saved correctly.

PyTest

from myapp.models import Item

@pytest.mark.[1]
def test_item_creation([2]):
    item = Item(name='Test Item')
    item.save()
    assert Item.objects.count() == 1

Drag options to blanks, or click blank then click option'

Adjango_db

Bclient

Cdb

Drequest

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'client' instead of 'db' as a fixture.

Missing the django_db mark.

The test needs the django_db mark to access the database and the db fixture to use the database in the test function.

5fill in blank

hard

Fill all three blanks to write a test that uses the Django test client to check the homepage response and content.

PyTest

def test_homepage_content([1]):
    response = [2].get('/')
    assert response.status_code == 200
    assert '[3]' in response.content.decode()

Drag options to blanks, or click blank then click option'

Aclient

CWelcome

Ddb

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'db' instead of 'client' for the fixture.

Checking for wrong content string.

The test function uses the 'client' fixture to make a GET request. It checks the status code and verifies that the word 'Welcome' is in the response content.

Practice

1. What is the main purpose of using @pytest.mark.django_db in pytest-django tests?

easy

A. To skip the test when the database is not available

B. To disable database migrations during the test

C. To mark the test as a slow test

D. To allow the test to access and modify the Django database

Solution

1. Step 1: Understand the role of @pytest.mark.django_db

   This marker tells pytest that the test needs database access, so pytest sets up the test database properly.

2. Step 2: Identify what happens without the marker

   Without this marker, tests cannot access or modify the database and will fail if they try.

3. Final Answer:

   To allow the test to access and modify the Django database -> Option D

4. Quick Check:

   Database access marker = B [OK]

Hint: Use @pytest.mark.django_db to enable DB access in tests [OK]

Common Mistakes:

• Thinking it skips tests instead of enabling DB access
• Confusing it with marking tests as slow
• Assuming it disables migrations

2. Which of the following is the correct way to use the Django test client fixture in pytest-django?

easy

A. def test_view(client): response = client.get('/'); assert response.status_code == 200

B. def test_view(): response = client.get('/'); assert response.status_code == 200

C. def test_view(client): response = client.post('/'); assert response.status_code = 200

D. def test_view(client): response = client.get('/'); assert response.status == 200

Solution

1. Step 1: Check the function signature and usage

   The test function must accept the client fixture as a parameter to use it.

2. Step 2: Verify the assertion syntax

   The assertion must use == to compare response.status_code to 200.

3. Final Answer:

   def test_view(client): response = client.get('/'); assert response.status_code == 200 -> Option A

4. Quick Check:

   Correct fixture use and assertion = C [OK]

Hint: Pass client as parameter and use response.status_code == 200 [OK]

Common Mistakes:

• Not passing client as a parameter
• Using single = instead of == in assertion
• Checking response.status instead of response.status_code

3. Given the following test code using pytest-django, what will be the output when running the test?

import pytest
from django.contrib.auth.models import User

@pytest.mark.django_db
def test_user_count():
    User.objects.create(username='alice')
    User.objects.create(username='bob')
    count = User.objects.count()
    assert count == 2
    print(count)

medium

A. Test fails because count is 0

B. Test passes and prints 2

C. Test raises a database error

D. Test passes but prints 0

Solution

1. Step 1: Analyze database access and object creation

   The test uses @pytest.mark.django_db, so it can create User objects in the test database.

2. Step 2: Count the User objects and assert

   Two users are created, so User.objects.count() returns 2, matching the assertion.

3. Final Answer:

   Test passes and prints 2 -> Option B

4. Quick Check:

   User count = 2 [OK]

Hint: Mark test with django_db to create and count users correctly [OK]

Common Mistakes:

• Forgetting @pytest.mark.django_db causes DB errors
• Assuming count is zero without creation
• Confusing print output with test result

4. Identify the error in this pytest-django test code and how to fix it:

def test_create_user():
    User.objects.create(username='charlie')
    assert User.objects.count() == 1

medium

A. Test function name should start with 'test_'

B. User model is not imported

C. Missing @pytest.mark.django_db decorator to allow DB access

D. Assertion should check for 0 instead of 1

Solution

1. Step 1: Check database access requirement

   The test tries to create a User in the database but lacks @pytest.mark.django_db, so DB access is not allowed.

2. Step 2: Fix by adding the missing decorator

   Adding @pytest.mark.django_db above the test function enables database access and fixes the error.

3. Final Answer:

   Missing @pytest.mark.django_db decorator to allow DB access -> Option C

4. Quick Check:

   DB access decorator missing = D [OK]

Hint: Add @pytest.mark.django_db to tests using the database [OK]

Common Mistakes:

• Not adding the django_db marker
• Assuming import errors without checking imports
• Misunderstanding assertion values

5. You want to test a Django view that requires a logged-in user using pytest-django. Which is the best way to simulate a logged-in user in your test?

hard

A. Use the client.force_login(user) method after creating a user in the test database

B. Set a session variable manually without creating a user

C. Call the view function directly without using the client fixture

D. Use @pytest.mark.django_db without logging in the user

Solution

1. Step 1: Understand how to simulate login in pytest-django

   The client.force_login(user) method logs in the user for the test client session.

2. Step 2: Create a user in the test database first

   You must create a user in the test database (with @pytest.mark.django_db) before calling force_login.

3. Final Answer:

   Use the client.force_login(user) method after creating a user in the test database -> Option A

4. Quick Check:

   Use force_login with created user = A [OK]

Hint: Create user and call client.force_login(user) to simulate login [OK]

Common Mistakes:

• Trying to set session manually without user
• Calling views directly without client
• Forgetting to create user before login