Book Image

Mastering React Test-Driven Development - Second Edition

By : Daniel Irvine
Book Image

Mastering React Test-Driven Development - Second Edition

By: Daniel Irvine

Overview of this book

Test-driven development (TDD) is a programming workflow that helps you build your apps by specifying behavior as automated tests. The TDD workflow future-proofs apps so that they can be modified without fear of breaking existing functionality. Another benefit of TDD is that it helps software development teams communicate their intentions more clearly, by way of test specifications. This book teaches you how to apply TDD when building React apps. You’ll create a sample app using the same React libraries and tools that professional React developers use, such as Jest, React Router, Redux, Relay (GraphQL), Cucumber, and Puppeteer. The TDD workflow is supported by various testing techniques and patterns, which are useful even if you’re not following the TDD process. This book covers these techniques by walking you through the creation of a component test framework. You’ll learn automated testing theory which will help you work with any of the test libraries that are in standard usage today, such as React Testing Library. This second edition has been revised with a stronger focus on concise code examples and has been fully updated for React 18. By the end of this TDD book, you’ll be able to use React, Redux, and GraphQL to develop robust web apps.
Table of Contents (26 chapters)
1
Part 1 – Exploring the TDD Workflow
10
Part 2 – Building Application Features
16
Part 3 – Interactivity
20
Part 4 – Behavior-Driven Development with Cucumber

Test-driving radio button groups

Now that we have our table with headings in place, it’s time to add radio buttons to each of the table cells. Not all cells will have radio buttons – only those that represent an available time slot will have a radio button.

This means we’ll need to pass in another new prop to AppointmentForm that will help us determine which time slots to show. This prop is availableTimeSlots, which is an array of objects that list times that are still available. Follow these steps:

  1. Add the following test, which establishes a value for the availableTimeSlots prop and then checks that radio buttons have been rendered for each of those slots:
    it("renders radio buttons in the correct table cell positions", () => {
      const oneDayInMs = 24 * 60 * 60 * 1000;
      const today = new Date();
      const tomorrow = new Date(
        today.getTime() + oneDayInMs
      );
      const...