What Is Test-Driven Development And What Are Its Benefits?
Software Development
Ricky Philip June 24, 2022

Every web development company or software developer aspires to make their code clear, simple, and free of bugs. To achieve this, rather than aiming for the optimum solution in the first pass, developers can make sure that the code and tests are iteratively built together one use case at a time. This method, which is also known as test-driven development (TDD) is a part of many coding disciplines that ensure better test coverage, and improved code quality, and it can also support continuous delivery.

Therefore, if you are looking for:

  • Reduced defects by encouraging more unit testing.
  • Improved productivity by reducing the need for manual regression tests.
  • Improved test coverage due to awareness of which functions are tested.
  • Improved performance of testing codes separately.

Then Test-driven development (TDD) is the right choice for your software development or application development project.

What is Test-driven Development (TDD)?

Test-Driven Development (TDD) is a method of software development in which developers have to initially create test cases that are as simple and easily understandable as possible. The ultimate aim of these tests is to specify and validate what the code will do and to ensure if the code efficiently does it. In simple terms, rather than writing the complete code at the beginning and then testing it, developers can first ensure that the codes are simple, and error-free and then implement it into the program.

So why not simply test the code after implementing it?

Finding an error could be quite difficult once the entire software development is complete. Moreover, this error which could have been a very minute bug in the initial phase could expand during the development process and affect other parts of the code as well, making it far more challenging to fix the issue. Also, the cost of fixing these errors and the time taken to correct it will be more during the final stages of software development. Therefore, it is always better to save time, expense, and most importantly the stress on the QA team by leveraging test automation initially in the code before implementing it.

Test-Driven Development

Therefore, if test cases fail, developers get the chance to fix them first and then move on to trying to fix production bugs. The idea behind TDD is that it allows developers to refactor quickly and seamlessly while making sure they don’t get stuck in an endless loop of debugging due to defects in their code.

Also Read: Why Should Software Development Companies Prefer Agile Testing And Not Traditional Software Testing?

Process of Test-driven Development (TDD)

  1. Test First: Test-driven development is a method that starts with tests, not code, as the first step in building a new application.
  2. Automated testing: When you write tests first, you can build your entire application by automating those tests. 
  3. Cleanly separated concerns: When you write tests first, you can separate concerns so that each piece of your application has its responsibility.
  4. Clear separation between business logic and data access layers: You can decouple your business logic from your data access layers so that it’s easier to change when necessary.
  5. Reduced risk of regression bugs: By writing tests first you have a much higher chance of catching many bugs before they occur.

Benefits Of Test-Driven Development (TDD)

Test-driven development is a software development methodology that uses tests to drive the design and implementation of code. Tests are written before the implementation occurs and provide automated verification that the implementation meets the specification. Test-driven development is designed to improve software quality, reduce defect rates, and cost less than other approaches. In this software development process, the tests are written first, and then the software is built. The advantage of this process is that it forces the developer to think about the code they write in terms of its impact on the system, rather than just writing it and hoping for the best.

The top benefits of test-driven development:

1) It is cost-efficient

Software maintenance costs can be huge, especially when it comes to legacy systems. For example, suppose your company decides to upgrade from version 1 to version 2 of an application. In that case, there’s a good chance that some configuration files will need updating (which could mean thousands of dollars). If these files are not properly tested before going live, then there’s a good chance that they will fail during production use. In addition, if changes are made that affect how any existing tests work (for example, adding new functionality), those tests may also fail when running against that new code. Therefore, when developers test the code initially even before implementing it, they are assured that the implemented code is error-free and effective. This significantly reduces time spent on application deployment and moreover decreases the cost of development.

2) Requirement driven development

Test-driven development enables requirements-driven development. This means that developers can create their software based on their business needs instead of having to assume what users want from the software. This makes the project more efficient because there are no assumptions made about how users will use the product or what kind of environment they will be using it in. This helps prevent misunderstandings between developers and clients which can cause delays in delivering products on time and within budget. It also helps avoid costly rework later on down the road if something goes wrong during testing or if changes need to be made after delivery due to unforeseen circumstances (e.g., new customers).

Also Read: What Is Automated Software Testing And How Does It Make Software Development Much Easier?

3) Tests are documentation for developers and QA engineers

Tests are a great way to document what your code does. While testing the code before development, project managers or clients who need to understand your code don’t have to guess from reading the source code itself or enquire with someone else who worked on the project at some point in time. Test-driven development can also be used as an early indicator of potential problems, which reduces risks by allowing developers and QA engineers to catch problems early on in their life cycle so that they can be fixed before they become too difficult or expensive to fix later on once they’ve become more widespread.

Test-Driven Development

Other benefits of test-driven development include:

  • Tests will be used as documentation for the code and this will help to improve the readability of your code.
  • Another benefit is that you can easily find bugs in the code by running a set of tests, and this will help to reduce bug time and makes the entire software development process much easier.
  • The third benefit is that your tests are independent of any other library or framework and as such, they will work with any other codebase.
  • If you have an existing codebase and want to refactor it, then using TDD is one way to do it without worrying about breaking anything else in the system or breaking dependencies between libraries or frameworks.
  • It’s easier to refactor code when no surprises are waiting for you at every turn — when all the test cases have been written before any actual code was written.
  • If a class has a bunch of small methods that do simple things well, it’s easy to reuse them in another context where they perform similar tasks but with different inputs or expectations. The same is true for classes that contain reusable pieces of infrastructure or abstractions — like factory objects or interfaces — which can be used in multiple applications without having to rewrite them, again and again, each time they’re used.


Test-driven development can be an efficient solution for both testers and developers throughout the software development life cycle (SDLC). This innovative software development strategy is being quickly adopted by both agile software developers and Agile DBAs. It helps them in the development of application source code and also plays an integral role in database development. TDD does not replace traditional testing, instead, it defines a proven way to ensure effective unit testing. 

Test-Driven Development


Author Bio

Ricky Philip is a content strategist, who has an unparalleled dedication to building productive and engaging website content that attracts traffic and increase search engine rankings. If not typing furiously on his keyboard, Ricky is constantly learning ways to enhance search traffic acquisitions.