In Apiumtech we love TDD. In this article, I will be explaining what is TDD exactly and what are the benefits of Test Driven Development and why you should use it in software development, specially working in an Agile way.
What is TDD or Test Driven Development
Test-driven development (TDD) is a software development process that relies on the repetition of a very short development cycle. First, the developer writes an (initially failing) automated test case that defines a desired improvement or new function, then produces the minimum amount of code to pass that test, and finally refactors the new code to acceptable standards. In Test Driven Development (TDD) automated unit tests are written before the code is actually written. Running these tests give you fast confirmation of whether your code behaves as it should or not.
Usually people think, that automated testing increases the amount of development time. However, we have been using TDD for many years and we can say with no doubt that automated tests actually allows developers and the team to develop the project much faster and with a higher quality.
Maybe knowing the advantages of TDD will convince you. Working with TDD for more than 10 years, we came to the conclusion that those are the 20 main benefits of test driven development:
20 Benefits of test driven development
- Writing the tests first requires you to really consider what do you want from the code
- Fast feedback
- Creates a detailed specification
- Reduces time spent on rework
- Less time spent in the debugger
- Identify the error/problem quickly
- Tells you whether your last change (or refactoring) has broken previously working codes
- Allows the design to evolve and adapt to your changing understanding of the problem
- Forces radical simplification of the code, you will only write codes in response to the requirements of the tests
- Forces you to write small classes focused on one thing
- Creates SOLID code
- Cleans Interface
- Maintainable, Flexible & Easily Extensible
- The resulting Unit Tests are simple and act as documentation for the code. Since TDD use-cases are written as tests, other programmers can view the tests as usage examples of how the code is intended to work
- Shortens the development Time to Market
- Increases the programmer’s productivity
- Cuts development costs
- Improves quality
- Reduces bugs
- TDD gives programmers the confidence to change the larger architecture of an application when adding new functionality. Without the flexibility of TDD, developers frequently add new functionality by virtually bolting it to the existing application without true integration – clearly, this can cause problems down the road
When programming, the bigger the code base gets, the harder it gets to move further or to change the code because you get scare of messing it up easily. If you have automated tests, they become your safety net, allowing you to see what is the mistake, where it is and how it affects the system. It helps identify errors in a really short period of time. These tests give developers very fast feedback when something breaks. These tests are also called change detectors. When you do a change, the tests will detect very soon if there are any problems or mistakes.
Conclusion about TDD
TDD provides its best results when the code is constantly improved. Benefits of test driven development is more than just simple validation of correctness; it can also drive the design of a program. Because of the testing modules that are built into the continuous integration development model, organizations using a TDD approach can easily make changes to their applications – all of that without the fear of ‘breaking’ the application and hamstringing their daily operations.
TDD leads to more modularized, flexible & extensible code. That is due to the fact that the methodology requires that the developers think of the software in terms of small units that can be written and tested independently and integrated together later. This leads to smaller, more focused classes, looser coupling & cleaner interfaces.
One of the benefits of test driven development is that is gives organizations the ability to painlessly update their software to address new business requirements or other unforeseen variables. A successful organization is one that can react to changing environments and address improvement suggestions with aplomb. Test driven development is the methodology that makes such flexibility, maintainability and extensibility possible.