Testing models in Django - Mini Project: Build & Apply

Testing models in Django

📖 Scenario: You are building a simple Django app to manage books in a library. You want to make sure your Book model works correctly by writing tests.

🎯 Goal: Write tests for the Book model to check that it saves and retrieves data correctly.

📋 What You'll Learn

Create a Book model with fields title and author

Add a test case class for the Book model

Write a test method to create and save a Book instance

Write a test method to retrieve the saved Book and check its fields

💡 Why This Matters

🌍 Real World

Testing models ensures your data structure works correctly before your app runs in production. It helps catch bugs early.

💼 Career

Writing model tests is a key skill for Django developers to maintain reliable and maintainable codebases.

1

Create the Book model

Create a Django model called Book with two fields: title as a CharField with max length 100, and author as a CharField with max length 50.

Django

# Your code here to define the Book model

Need a hint?

Use models.CharField for text fields and set max_length as instructed.

2

Set up the test case class

Create a test case class called BookModelTest that inherits from django.test.TestCase.

Django

from django.test import TestCase

# Your code here to define BookModelTest class

Need a hint?

Import TestCase from django.test and create an empty test class.

3

Write a test to create and save a Book

Inside the BookModelTest class, write a test method called test_create_book that creates a Book instance with title set to 'Django for Beginners' and author set to 'William S. Vincent', then saves it.

Django

from django.db import models

class Book(models.Model):
    title = models.CharField(max_length=100)
    author = models.CharField(max_length=50)

from django.test import TestCase

class BookModelTest(TestCase):
    # Write test_create_book method here
    # Your code here

Need a hint?

Define a method starting with test_ inside the test class. Create and save the Book instance inside it.

4

Write a test to retrieve and check the Book

Add a test method called test_retrieve_book inside BookModelTest that retrieves the saved Book by filtering title='Django for Beginners' and asserts that the author is 'William S. Vincent' using self.assertEqual.

Django

from django.db import models

class Book(models.Model):
    title = models.CharField(max_length=100)
    author = models.CharField(max_length=50)

from django.test import TestCase

class BookModelTest(TestCase):
    def test_create_book(self):
        book = Book(title='Django for Beginners', author='William S. Vincent')
        book.save()

    # Write test_retrieve_book method here
    # Your code here

Need a hint?

Use Book.objects.get() to find the book and self.assertEqual() to check the author.