Test-Driven Development with Python, 3rd Edition

Chapter 2. Extending Our Functional Test Using the unittest Module

Let’s adapt our test, which currently checks for the default Django “it worked” page, and check instead for some of the things we want to see on the real front page of our site.

Time to reveal what kind of web app we’re building: a to-do lists site! I know, I know, every other web dev tutorial online is also a to-do lists app, or maybe a blog or a polls app. I’m very much following fashion.

The reason is that a to-do list is a really nice example. At its most basic, it is very simple indeed—​just a list of text strings—​so it’s easy to get a “minimum viable” list app up and running. But it can be extended in all sorts of ways—​different persistence models, adding deadlines, reminders, sharing with other users, and improving the client-side UI. There’s no reason to be limited to just “to-do” lists either; they could be any kind of lists. But the point is that it should enable me to demonstrate all of the main aspects of web programming, and how you apply TDD to them.

Using a Functional Test to Scope Out a Minimum Viable App

Tests that use Selenium let us drive a real web browser, so they really let us see how the application functions from the user’s point of view. That’s why they’re called functional tests.

This means that an FT can be a sort of specification for your application. It tends to track what you might call a user story, and follows how the user might work with a particular feature and how the app ...