Have you ever dealt with a situation wherein you come up with a new feature or bugfix for your software, which was then tested by your QA team, before being pushed to the codebase, only for it to break something else, and being finally withdrawn?

As an IT business solution provider, we see this sequence of events playing out frequently, leading to much frustration among development teams and cost escalations for businesses. This is also exactly the problem that is solved to a large extent by test-driven development, popularly known as TDD.

What is test-driven development, how to implement it, why and when to use it, and what are its pros and cons? Read on to know the answers.

What is Test-driven Development?

“TDD is what gets us the closest we can get to proving our code does what we want it to do all of the time.” – Peter Morlion, Red Star IT

Test-driven development is an iterative process that helps developers or an app development company to produce robust code in a faster way. How does it do that? Well, in TDD, you write the unit test for the code before writing the code itself. This test checks for a result that you’d want from your implementation code. Logically, such a test will fail at the beginning as you haven’t yet written the implementation code to achieve your intended result.

Next up, you write the implementation code that passes the unit test you wrote previously. Once it passes the test, you look for areas of your implementation code and test that can be improved without breaking the latter. You need to repeat this process for the rest of your code and until you have an adequate number of tests that cover all probable results.

That, in essence, is what test-driven development is all about. In a later section, we go into details of each step involved in TDD.

Read more: What are Software Design Patterns & An Intro to Factory Design Pattern

Why Test-driven Development is Used?

TDD is widely used and there’s ample publicly-available evidence to back up its effectiveness. As for the latter, TDD drives down the number of bugs in your production code and enhances the code’s quality. This, in turn, makes your code easier to understand and maintain. Here’s a test-driven development example where the method helped reduce bugs by 50% in a legacy codebase.

If you prefer a more formal and peer-reviewed evaluation of test-driven development, check out this study that stretched over five years and showed that if you hire dedicated resources who are new to TDD, they’re likely to produce higher quality software with TDD than the industry average.

How to Do Test-driven Development?

Understanding the test-driven development framework and how to implement it becomes easier if we break down the process into five smaller steps.

1) Write a Test

2) Confirm if the Test Case Fails

3) Write the Code to Pass the Written Test

4) Confirm Your Test Passes

5) Refactor Your Code

6) Repeat the Process

Read more: What is Factory Method: A Factory Design Pattern Case Study

What Are the Pros and Cons of Test-driven Development?

The benefits of test-driven development extend from an individual developer level to an organizational level. As such, it can positively impact the latter’s bottom line when implemented correctly.

Pros of Test-driven Development:

1) Reduces Overall Development Time

2) Reduces Debugging Time

3) Gives Due Importance to User Experience

Cons of Test-driven Development:

1) More Time Consuming

2) Difficult to Apply in All Cases

3) Can Cause Tunnel Vision Development

Read more: What is Observer Design Pattern: A Brief Guide with a Case Study

Over to You

If you’re wondering if and when to use test-driven development in your project, a simple thumb rule is to see if you’re using a complex algorithm and if you have a clear outline of your software project. TDD can help you tackle the former by breaking down your project into smaller sections while the latter ensures TDD doesn’t end up inflating your project’s complexity and timeline unnecessarily.

If you still have questions about using test-driven development for your project, drop us a line and have our dedicated development team get back to you. As an IT business solution provider for almost 20 years, we’ve used TDD extensively to build robust, maintainable, extensible, and scalable software products for businesses in Asia, Africa, Europe, and North America.

View Original: Test Driven Development