Test-Driven Development with Python

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! In doing so we’re very much following fashion: a few years ago all web tutorials were about building a blog. Then it was forums and polls; nowadays it’s all to-do lists.

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 allow 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 ...