Factory Boy for test data in Django - Mini Project: Build & Apply

Factory Boy for test data

📖 Scenario: You are building a Django app for a bookstore. You want to create test data easily for your Book model using Factory Boy.

🎯 Goal: Create a Factory Boy factory for the Book model to generate test data with fixed values and then use it to create a book instance.

📋 What You'll Learn

Create a Django model called Book with fields title (string) and author (string).

Create a Factory Boy factory class called BookFactory for the Book model.

Set default values for title and author in the factory.

Use the factory to create a Book instance.

💡 Why This Matters

🌍 Real World

Factories help developers quickly create realistic test data for Django models, making testing easier and more reliable.

💼 Career

Knowing how to use Factory Boy is valuable for Django developers writing automated tests and maintaining code quality.

1

Create the Book model

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

Django

from django.db import models

# Define the Book model below
# Your code here

Need a hint?

Use models.CharField(max_length=100) for both fields.

2

Create the BookFactory class

In a new file factories.py, import factory and the Book model. Create a factory class called BookFactory that inherits from factory.django.DjangoModelFactory. Set the title field to 'The Great Gatsby' and the author field to 'F. Scott Fitzgerald'.

Django

from django.db import models

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

import factory
from .models import Book

# Define BookFactory below
# Your code here

Need a hint?

Remember to set class Meta with model = Book.

3

Use BookFactory to create a Book instance

In a test file or script, import BookFactory and create a book instance by calling BookFactory(). Assign it to a variable called book.

Django

from django.db import models

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

import factory
from .models import Book

class BookFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = Book

    title = 'The Great Gatsby'
    author = 'F. Scott Fitzgerald'

# Create a book instance using BookFactory
# Your code here

Need a hint?

Call BookFactory() and assign it to book.

4

Add __str__ method to Book model

Add a __str__ method to the Book model that returns the book's title. This helps display the book nicely in Django admin and shell.

Django

from django.db import models

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

    # Add __str__ method below
    # Your code here

import factory
from .models import Book

class BookFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = Book

    title = 'The Great Gatsby'
    author = 'F. Scott Fitzgerald'

book = BookFactory()

Need a hint?

Define def __str__(self): inside Book and return self.title.