Unit Tests

Kacper Hernacki

Oct 11, 2023 — 3 min read

Test-Driven Development

This newsletter will be short because I am packing for a few days' trip to the Arctic adventure in North Norway. However, the content provided here should be very valuable in the context of web development or overall, the software development process.
I would love to introduce the concept of test-driven development. It is based on creating unit test scripts before implementing the features in a code base.

Why to implement Test-Driven Development?

Implementing Test-Driven Development (TDD) offers several advantages that contribute to the development of high-quality, robust, and maintainable software. Here's a breakdown of some key benefits:

📌 Early Bug Detection:

TDD requires writing tests before the actual code, which helps catch bugs at the earliest stages of development. This early bug detection can save time and resources compared to finding and fixing bugs later in the process.

📌 Improved Design:

TDD can lead to better software design, as it requires developers to think through their code in smaller, more manageable pieces. This often results in simpler, clearer, and more modular code.

📌 Code Confidence:

Having a suite of tests that covers your code means developers can make changes or refactor with confidence, knowing that they'll quickly spot any regressions if they introduce bugs.

📌 Documentation:

The test suite serves as a form of documentation. It shows how the system is supposed to work and how to use the different parts of the code. This can be invaluable for onboarding new developers or revisiting a project after some time.

📌 Ease of Refactoring:

With a comprehensive suite of tests, developers are more at ease when refactoring or making changes to the code. They can quickly verify whether the changes have broken anything.

📌 Enhanced Collaboration:

TDD encourages clearer communication among team members about requirements and functionality, which can be particularly useful in Agile or team-based settings.

📌 Incremental Development:

TDD supports incremental development and iterative design, making it easier to adapt to changes in requirements.

📌 Professional Development:

Practicing TDD can improve developers' skills over time by promoting a disciplined approach to coding and a deeper understanding of software design principles.

📌 Reduced Debugging Time:

By catching issues early, there's typically less time spent in the debugger trying to identify and resolve bugs.

📌 Cost Efficiency:

Although TDD might seem time-consuming initially, it tends to pay off in the long term by reducing the time and cost associated with debugging and maintaining the code.

📌 Customer Satisfaction:

Delivering a well-tested, high-quality product can lead to increased customer satisfaction.

The decision to implement TDD should be based on a careful consideration of these benefits alongside the needs and constraints of your particular project.

Below I show the practical part of TDD with next.js 13 and Jest. I hope it will be helpful.

GitHub repo:

Youtube video:

🧠 Casual reflections

After the weekend I would be focused on finishing free ebook chapters for every subscriber of the newsletter. It is about modern development, tips and tricks, roadmap, etc.

However, I will be looking for some talented junior developers to create a team of freelancers and create a software agency. I am investigating a few sources of projects, if you are willing to join, DM me on:
💌 hernackikacper@gmail.com

or in other social media: