The Definitive Guide to TDD in React: Writing Tests That Guarantee Success

Imagine coding with a safety net that catches errors before they happen. That's the power of TDD. In this article, we'll dive into how it can revolutionize your development workflow. In Test Driven Development (TDD), a developer writes test cases first before actually writing code to implement the functionality. There are several practical benefits to developing code with the TDD approach such as:

  • Higher quality code: Thinking about tests upfront forces you to consider requirements and design more carefully.
  • Rapid feedback: You get instant validation, reducing the time spent debugging.
  • Comprehensive test coverage: TDD ensures that your entire codebase is thoroughly tested.
  • Refactoring confidence: With a strong test suite, you can confidently improve your code without fear of breaking things.
  • Living documentation: Your tests serve as examples of how the code is meant to be used.

TDD has three main phases: Red, Green, and Refactor. The red phase means writing a test case and watching it fail. The green phase means writing minimum code to pass the test case. The refactor phase means improving the code with refactoring for better structure, readability, and maintainability without changing the functionality while ensuring test cases still pass. We will build a Login Page in React, and cover all these phases in detail. The full code for the project is available here, but I highly encourage you to follow along as TDD is as much about the process as it's about the end product.

TDD, BDD, and ATDD

Software development is an iterative process that involves writing, testing, and refining code until it meets the requirements. Test-driven development (TDD), behavior-driven development (BDD), and acceptance test-driven development (ATDD) are three methodologies that support this process. TDD, BDD, and ATDD are all methodologies used in software development for testing and ensuring quality. While they all aim to improve software development quality, they differ in their approach and focus. This article will explore the differences between TDD, BDD, and ATDD.

Test-Driven Development (TDD)

Test-driven development (TDD) is a software development methodology focusing on writing tests before writing the code. It is an iterative process that involves writing a test, running the test, and then writing the code that passes the test. The goal of TDD is to write high-quality, maintainable code that meets the requirements and is free from bugs.

TDD and the Impact on Security

Test-driven development (TDD) is a software development approach that prioritizes writing automated tests while creating the actual code. There follows a cycle of writing a failed test, writing the code to make the test pass, and then refactoring the code. TDD was originally developed to ensure the quality, maintainability and expandability of the software created over the long term. The specific knowledge about the individual source text passages should also be shown in the tests. Thus, a transfer of responsibility between developers is supported. Better than any documentation, tests are always up-to-date regarding the function implemented in the source code.

However, TDD also has a positive impact on the security of a program. And that's what we're going to look at now.

TDD vs. BDD: Choosing The Suitable Framework

Most Software Developers in Test are familiar with Test-Driven Development, or TDD, but Behavior-Driven Development, or BDD, is often misunderstood. The truth is that both of these approaches have advantages and disadvantages to consider.

This blog deep dives into TDD vs. BDD comparison by looking at both these approaches individually. Later, we would compare them to functionalities, supported frameworks, and more.
I could say BDD is merely the evolution of TDD.

Beyond Coding: The 5 Must-Have Skills to Have If You Want to Become a Senior Programmer

In a Nutshell

  • We instinctively equate programming with writing code. Because of it, we focus primarily on code design and creation skills: mastering languages and frameworks, clean code, design patterns, TDD, and architecture.
  • But creating new code is only a fraction of what we do every day. For example, we spend much more time navigating, searching, analyzing, reviewing, and debugging code than writing.
  • Though these activities seem straightforward, they require as specialized skills and experience as coding. Mastering them is what separates true senior programmers from the crowd. And what makes you stand out and get noticed at a new job.
  • In this post, I'll look at the key traits of professional software development, how they impact what you do every day, and explore what skills you need to become a complete programmer.

The Common Misconception About Programming

People instinctively equate programming with writing code. And it doesn't apply only to lay people. But, unfortunately, many experienced programmers also do have this bias. Not in a naive way, of course. We know that coding isn't just typing and that having crazy keyboard skills doesn't make you a great programmer. But even then, we focus mainly on code creation skills.

Think for a moment about what most books, blog posts, and talks are about. What sparks the most heated discussions in your team? What are the most common coding interview questions?

CoffeeScript: a TDD example

CoffeeScript is a language building an abstraction over JavaScript (as the similar name suggests.) It is an abstraction over the syntax of JavaScript, not over its concepts: the language is still based on functions as objects which may bind to other objects, and prototypical inheritance.

CoffeeScript favors the best practices of JavaScript by transforming abstractions you would have written anyway, or borrowed from a framework, into language concepts for maximum conciseness. It has a compilation step - as every language must compile to a lower-level one, like C or Java.

30 Common CI/CD Interview Questions (With Answers)

Acing a CI/CD interview is all about preparation. Preparation starts with collecting as much information as you can about the prospective company, and their history, product, and interviewing process.

Next in the list is to brush up your technical skills because knowing your technical stuff will make you stand out. Questions (like the ones in this article) are a great way of testing your knowledge. To help you, we’ve collected and answered 30 common CI/CD interview questions. How many can you answer?

How Many of These Questions Can You Answer?

  1. What is version control?
  2. What is Git?
  3. What is a Git repository?
  4. Which other version control tools do you know of?
  5. What is a Git branch?
  6. What is merging?
  7. What is trunk-based development?
  8. What is Gitflow, and how does it compare to trunk-based development?
  9. How long should a branch live?
  10. What is continuous integration?
  11. How do CI and version control relate to one another?
  12. What’s the difference between continuous integration, continuous delivery, and continuous deployment?
  13. Name some benefits of CI/CD.
  14. What are the most important characteristics in a CI/CD platform?
  15. What is the build stage?
  16. What’s the difference between a hosted and a cloud-based CI/CD platform?
  17. How long should a build take?
  18. Is security important in CI/CD? What mechanisms are there to secure it?
  19. Can you name some deployment strategies?
  20. How does testing fit into CI?
  21. Should testing always be automated?
  22. Name a few types of tests used in software development.
  23. How many tests should a project have?
  24. What is a flaky test?
  25. What is TDD?
  26. What is the main difference between BDD and TDD?
  27. What is test coverage?
  28. Does test coverage need to be 100%?
  29. How can you optimize tests in CI?
  30. What’s the difference between end-to-end testing and acceptance testing?

Version Control

CI/CD interview questions may include version control and Git as a topic.

Do You Need to Test Everything?

At my previous job at a big multinational company, we didn’t have anything remotely resembling an automated test. What manual testing we did consisted of dragging and dropping a folder and mashing F5. When we skipped testing, however, the users ended up doing it for us. After they did their round of testing, they would call or show up at our office, wondering angrily why the product was not working as they expected.

I start with this story because I don’t want you to think that I do not value tests. I do. Very much. I believe we can’t live without them. But you can have too much of a good thing. However vital water may be, too much of it results in a flood.

You Get a Test; You Get a Test; Everyboooody Gets a Test!

Everybody gets a test…

Tests are living documentation, messages to other developers (and our future selves) about what the code is supposed to do. Tests enforce requirements and provide feedback, telling us when something breaks.

The Economics of TDD

From a management standpoint, Test-Driven Development (TDD) can be a difficult sell. It involves a relatively large upfront investment, has no obvious business benefits, and (most important of all) the customer is paying for functionality, not tests.

Tempting as it is to cut testing in order to reach the next milestone in the project, it is a mistake because, as we’ll see, TDD can help us accelerate development and reduce costs over a project’s lifecycle.

Understanding Bounded Context

Introduction

If someone asks you the meaning of a word, most of the time you don’t have an absolute meaning and end up asking for the context in which it is used. You need to know the context to get to the correct meaning. Similarly, to know your domain model right, you get to know the bounded context it is in.

Let us understand the path that leads to bounded contexts.

Why Don’t Developers Write More Tests?

I regularly speak at conferences about testing microservices, and one of the first questions I ask attendees is whether they write tests or not. The room is usually split 50-50 between developers who write tests for their code and those who do not. This disparity gets more pronounced when I give guest lectures at coding bootcamps where I’ve found that fewer than 1 in 10 grads actually know how to write a unit test.

My anecdotal observations have been backed up by surveys as well. Diffblue found 42% of developers skip writing tests and Stack Overflow found 37% of developers don’t write tests for their code at work.

TDD vs. BDD vs. ATDD — Developers’ Methodologies to Smoothly Navigate Complex Development Processes

Introduction

The last decade in the history of humanity can be easily called the technological revolution. The pandemic made it starker than ever before. The developers need to keep pace with the new languages, frameworks, tools, and processes that come into being every second.

To write code is a developer’s second nature. But, what code to write, how to write it, when to write it, and for what purpose may easily overwhelm even the most experienced and expert developers when it is raining new codes and processes day in and day out.

JUnit Test Groups for More Reliable Development

Introduction

As a product is being developed and maintained its test suite is enriched as features and functionalities are added and enhanced. Ideally, development teams should aim having a lot of quick unit tests that are run whenever modifications in the code are made. It is great if these are written before or at least together with the tested code, cover as many use cases as possible and finish running after a reasonable amount of time. By all means, a reasonable amount of time is an entity difficult to quantify. 

On the other hand, there are a lot of live products that solve quite complex business problems whose thorough verification concerns cross-cutting through multiple application layers at once and thus, the number of integration tests is significant. Running all these unit and integration tests whenever the code is touched is not always feasible, as the productivity and the development speed is decreased considerably. Again, productivity and development speed are hard to quantify but should be always traded for correctness. 

Putting BDD in Practice Using Scala

This article aims to give a brief explanation of what BDD is and how it can be used to fill the information gap between stakeholders and development teams, ensuring everyone (technical or not) is involved in the project’s progress.

The first time I had contact with this approach to software development was a few years ago during a Massive Open Online Course (MOOC) and, I must warn you, I've never applied it in production. Nevertheless, I'm fully aware this is not the holy grail and it might not work so well as advertised, but the idea of having everyone on the team (not only developers) collaborating on the development process sounded very romantic to me.

What Is Test-Driven Development and Why It’s Important

One of the most essential steps of any software development project is testing. If this process is skipped, the results may be disastrous – both for the project and for the company. But when should software undergo testing? It seems logical to test the project when it is completed. However, the power of the classic test procedure is limited. Overengineering, rigid design, testability issues – are just a few problems you may face if you write the code first and test the implementation later. Luckily, there is a way to tackle such challenges and it is called – Test-driven development.

You may also like: A Test-Driven Approach to App Development: The Main Benefits for Your Business

I Tried Test-Driven Development for A Month and Survived

When I first heard about Test Driven Development (TDD) I immediately wrote it off as a technique that will slow me down, how on earth should I know exactly what my code will look like if I often refactor while coding. Besides, I’ve been coding for many years and understand how to write code that is “easily” testable. For me it made perfect sense to ignore this crazy idea. Then I realised TDD doesn’t mean what I thought it meant, you see the first time TDD was explained to me many years ago I was told “You write all your unit tests first” and that is what stuck with me. Even now when I ask developers what they understand about TDD that is the response I receive.

So what is TDD?

Test Driven Development is an iterative programming workflow whereby you write a single unit test and then write the code, if required, to make the test pass. When the test passes you refactor your code, including the tests, before writing the next test.

Acceptance Tests in Java With JGiven

Most of the developer community know what a unit test is, even they don’t write them. But there is still hope. The situation is changing. More and more projects hosted on GitHub contain unit tests.

In a standard set-up for Java projects like NetBeans, Maven, and JUnit, it is not that difficult to produce your first test code. Besides, this approach is used in Test Driven Development (TDD) and exists in other technologies like Behavioral Driven Development (BDD), also known as acceptance tests, which is what we will focus on in this article.