What Is TDD in Software Development?

by Anna Khrupa on Mar 10, 2022

As software development continues to advance, new developing approaches are introduced to make this process faster, easier, and more efficient. In the test driven development example, we can clearly see one of the most effective approaches to quick and high-quality software production. Read along to find out about the details of the TDD approach and its key advantages.

What Does Test Driven Development or TDD Mean?

Test Driven Development is a practice in software development that revolves around creating test cases before writing the code itself to see how it will behave. To put it simply, a separate test case for small functionalities is created. Every test undergoes a testing process, and a new piece of code is written only if this test fails. In the event of failure, another test case is created with adjustments to make the code free of bugs. New code is written only after failed test cases to avoid making duplicates.

The Test Driven Development process is conducted in three stages:

  1. Creating precise test cases – developers design test cases to verify the functionality of certain features of the software. Their task is to create test cases that will work. Although the majority of these tests fail, it is the exact intention of the process as such failures provide valuable insight for developers.
  2. Fixing the code – after test failure, developers need to implement minor adjustments to the code to eliminate errors and make it functional for the following testing.
  3. Revising the code – after the successful testing of the code, it is time to evaluate its potential for improvement. The code can be altered once again to enhance its performance, although it is crucial not to affect the overall performance of the software.

Test Driven Development Framework Options

TDD process is often implemented in projects based on different programming languages. There are various frameworks available for various languages, which makes the process more convenient. Here are some of the most commonly used frameworks for Test Driven Development:

  • DocTest, UnitTest – solutions for projects based on Python
  • JUnit – a popular choice for developers coding in Java
  • TestNG – another solution for Java. This framework is less limiting than the previous one
  • RSpec – a framework suitable for codes created with Ruby

Picking a suitable framework not only facilitates the TDD process but also delivers better results. There are many other frameworks that might be worth checking to find the most fitting option for a specific project.

Key Advantages of TDD Approach

Test Driven Development is a highly beneficial approach as it offers balanced solutions for all key activities of software development, such as writing a code, testing it, and designing the final product. Here are some of the main benefits of Test Driven Development for developers and businesses:

  • Flexible software design – with the TDD practice, developers focus on every separate feature and run all the necessary tests before starting to work on another one. The code becomes more high-quality with this type of testing, and it is much easier to detect errors and rewrite the code to fix them.
  • Easier maintenance of the code – it is much easier to work with an organized code. With the TDD approach, software developers deliver a rather clean and manageable code. It is more accessible and simple to work on smaller parts of the code, which is also more fitting for efficient testing. A clean and simple piece of code is also preferred in case there is a need to delegate certain work to another developer.
  • Improving the code – thanks to the Test Driven Development practice, it becomes possible to cut many hours of the entire testing and maintenance process. After the code is tested, it is obligatory to enhance an already working piece of code to make it more efficient. Clean code that is divided into smaller parts is more suitable for effective refactoring.
  • Cutting project costs – when implementing TDD, the amount of funds spent on a project decreases, as much less time and effort are spent on working with the code. Please note that expenses are lower in the long run, whereas those projects without the TDD approach might seem cheaper at first and turn out much more expensive afterwards.
  • Better code documentation – there is no need to create thorough documentation immediately as small chunks of code are easy to track. These pieces of code act like documentation themselves and can be documented later to save time.
  • Spending less time on debugging – there are notably fewer bugs and other issues involved in coding when you use the TDD solution. Fewer bugs mean significantly less time spent while working on the code. In addition, errors encountered during the use of the TDD approach can be detected and fixed faster.

These are only a few key factors why Test Driven Development is such a popular practice today. This practice plays a huge role in Agile Development, which requires sending feedback regularly to create the necessary product. With this approach, the demands and objectives regarding the end product can change quickly, which is why regular and swift feedback is important. The TDD approach fits perfectly into Agile Development as it allows providing feedback promptly thanks to working with small portions of the code. Bug fixes are delivered constantly, and the software can evolve and change as intended.


The Test Driven Development practice has numerous advantages. Working with smaller chunks of code separately allows examining each of them thoroughly to detect and eliminate bugs without affecting the entire system. With this method, top quality is guaranteed, although the code is regularly changed and improved in various ways. The code created under the TDD practice is generally cleaner and easier to approach, which is advantageous in situations when one developer has to work with a piece of code designed by another team member. With the help of various reliable frameworks, this procedure becomes accessible and effective. Businesses also often use TDD to reduce costs as the entire software development process becomes cheaper in the long run.



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