Getting started with TDD

If you're new to Test-Driven Development (TDD) and eager to integrate it into your projects, you've come to the right place. Here's a step-by-step learning guide to help you kickstart your journey with TDD. Getting started involves understanding the basics of TDD, practicing with specific exercises (katas), and delving deeper with additional resources.

1. TDD Fundamentals

Before diving into the practical aspect of it, it's essential to grasp the theory behind it: understanding what TDD is, its benefits, and how it differs from other software development methods.

The TDD process can be summarized into short development cycles known as Red-Green-Refactor cycles:

Red: In this cycle you must write an automated test for a new function that will initially fail because the function hasn't been implemented yet. This step ensures that the test is valid and that it requires the new function to pass.

Green: In this cycle you will write the minimum code necessary for the test to pass. This step focuses on getting the test to pass as quickly as possible, without dwelling on code perfection.

Refactor: Once the test has passed, you will adjust the code to improve its structure and quality while the tests continue to function. This may include removing redundancies, improving readability, and applying software design principles.

The 3 Laws of TDD

1. You cannot write production code without first writing a failing test.
2. You cannot write more than one unit test, and the test should be sufficient to fail (compilation failures are failures).
3. You can only write production code to make the single failing test pass.

For a deeper understanding of these concepts, Kent Beck's book "Test Driven Development: By Example" is an excellent resource to begin with. Through practical examples, Beck guides the reader in developing high-quality software iteratively. This book is a timeless classic that every developer must have in their toolkit.

An article that may also be helpful is "A Beginner's Guide to Test-Driven Development," which will help you understand the basic concepts of this methodology.

It's important to have a clear understanding of the theory to start your practice on a solid footing. If you get any doubts throughout these readings, don't hesitate to seek support from other publications or communities.

At Codurance, we believe that TDD is a practice that, when applied correctly, brings agility to software development processes, helps build more reliable and flexible code, and promotes sustainable and scalable quality solutions.

2. Take your first steps with Katas

Programming katas are hands-on exercises designed to enhance your skills through repetition and reflection. We recommend you start off with basic katas that will allow you to focus on the red-green-refactor cycle.
Some Katas to get started with:
  • The String Calculator Kata: Write tests for a simple calculator that adds, subtracts, multiplies, and divides.
  • FizzBuzz Kata: This exercise entails writing a program that prints numbers from 1 to 100, but with some specific restrictions.

3. Intermediate Practice

Once you feel comfortable with the basics, you'll be ready to tackle more challenging exercises.

Intermediate Katas:

  • ATM Machine Kata: Create an app that simulates ATM operations such as deposits, withdrawals, and transfers, applying TDD.
  • Shopping Cart Kata: Develop a system that manages the shopping cart for an online supermarket.
Keep in mind that practice leads to mastery, so feel free to repeat the exercises as many times as needed to solidify these foundational concepts.
4. Delve Deeper into TDD

Once you've gained some experience, explore advanced TDD concepts and discover how to apply them in more complex scenarios.

For example, the book "Growing Object-Oriented Software, Guided by Tests" by Steve Freeman and Nat Pryce is very useful for understanding how to apply TDD in object-oriented software.

Check out meetup events or online sessions covering more advanced topics such as TDD in web application development, TDD and design patterns, or TDD in microservices development. Here are some workshops available in English and Spanish.

5. Tools and Communities

Get familiar with some testing tools and frameworks specific to the programming language you use, such as JUnit for Java, pytest for Python, or RSpec for Ruby.

We also encourage you to engage in online communities or study groups focused on TDD. Seek out pair programming sessions or mentorship opportunities to practice TDD alongside fellow developers.

Final Recommendations

  • Regular practice is essential: The key to mastering TDD is consistent practice. Dedicate time regularly to solve katas and work on small projects.
  • Reflect and improve continuously: Take a moment after each kata or project to ponder on what you've learned and consider ways to enhance your skills.
  • Community Participation: Share your experiences and obstacles with the community. Feedback from other developers is priceless.
This learning path is designed to gradually build your skills in TDD, from basic to more advanced concepts, and will equip you with the necessary tools to effectively incorporate TDD into your software development projects.


Tell us about your challenges by clicking on the banner