A Guide to Test-Driven Development

As technology continues to advance at lightning speed, time-to-market is a critical differentiator between competing software products. Software development teams often face immense pressure to deliver solutions rapidly. However, speed can sometimes come at the expense of delivering high-quality, reliable code—resulting in costly consequences and dissatisfaction.

While many organizations have struggled to find the right balance between quality and speed, test-driven development (TDD) has emerged as a methodology that may be able to accomplish both. Read on to gain a deeper understanding of TDD and how it benefits software development.

What is Test-Driven Development (TDD)?

Unlike traditional testing, test-driven development (TDD) is a software development methodology focused on writing tests before writing and deploying the actual code. Developers will write test cases for each feature or functionality and create just enough code to pass the test. Test-Driven Development serves as a double-checking system that ensures every feature or line of code is bug-free before implementation.

How Does Test-Driven Development Work?

The test-driven development methodology works in five stages: writing tests, writing code, and refactoring.

1. Understanding the Feature Request

The first phase of test-driven development is to read and understand the request. This helps emphasize that each test has a purpose in satisfying an application or business objective.

2. Writing Tests

The second stage of TDD consists of writing a specific, automated test that describes an individual functionality of the application. In this phase, the test will fail until the code is written to satisfy it.

3. Writing Code

After creating the tests, developers will write the minimum amount of code required to pass the test.

4. Refactoring

In the last stage of TDD, developers will refine and improve the code to make it more modular and maintainable.

5. Repeat

Repeat steps 1-4 until desired functionality is complete.

Why Use TDD?

While TDD may have a learning curve and requires more time during the early phases of development, it can pay off in the long run. Here are just a few of the benefits of using TDD:

Produces High-Quality Code

A recent study by IEEE, a professional association for electronic and electrical engineers, found one of test-driven development’s most significant benefits is its ability to produce high-quality code. By focusing on one small step at a time, developers are able to narrow the focus to the desired functionality. This helps ensure the code is clean and optimized. Additionally, TDD has higher test coverage, which means the code is less likely to break.

Reduces Time Spent Debugging

According to a recent study by the University of Cambridge, software developers spend about 50% of their time debugging. By implementing test-driven development, developers can identify issues earlier and significantly reduce time spent debugging.

Enables Faster Development

In addition to reducing the number of bugs, test-driven development enhances the reusability of the code. TDD asks developers to create modular and loosely coupled code that is easily reusable, leading to shorter development time. TDD also speeds up development by integrating with Continuous Integration and Continuous Deployment (CI/CD) practices. Through rapid feedback and detection of issues, TDD can act as an automated safety net during code integration, ensuring a smoother development process.

Provides Clear Documentation

With test-driven development, developers write tests with strict and detailed specifications. These tests demonstrate how the code works, which can serve as documentation. Plus, it saves developers from the often laborious tasks of documentation.

Decreases Long-Term Cost

While test-driven development may be more expensive in the short term due to the number of tests per project, it can save money for an organization over the long-term. With traditional programming methods, testing often is left until the end. This can result in many bugs and other technical issues that go unnoticed—which can snowball and become expensive to fix. TDD can catch problems earlier in the process, saving quality assurance costs.

Learn Test-Driven Development

Test-driven development has become a game-changer for software developers. With an emphasis on testing and quality, learning test-driven development will empower you to build-user friendly, maintainable software. As a software engineer, possessing a deep understanding of TDD will help you and your team gain a competitive advantage.

The SJSU Coding Bootcamp will help you launch a successful coding career in as little as 16 weeks. This rigorous program includes training on TDD methodology that will prepare you to effectively utilize it throughout your career. Complete the no-cost, online application to begin the bootcamp admissions process today.