The Importance of Test-Driven Development (TDD)

Development is the leader of the market at present. Those who know development are earning and growing in their life. Suppose a developer develops a website or app in a company then we think that yes the developer has developed it and it is correct and has no errors. But actually, the app website or software we see is Test-Driven Development (TDD) Software.

What is TDD (Test Driven Development)?

TDD is a technique of development of any project where the developers create some small unit test cases before the actual code. As the name suggests, TDD is related to software testing.

1. The main motive of TDD is to modify the code part in which there are errors where the software fails.
2. It starts with designing and developing test cases for every small functionality of an application.
3. It is sometimes also known as Test First Development.

Test-Driven Development Process

This process can be classified into three phases which eventually form the cycle of TDD.

1. Red Phase

The red phase means to write a unit test case to test the software. In the software domain, any algorithm for any problem must be correct and directly writing an algorithm does not mean it is correct. So the question comes of how we will verify our algorithm. That is where the test cases (examples) come into the picture. By the test cases only, we can determine whether the software is working on all the possible conditions or not.

2. Green Phase

Green phase means to pass that test case i.e. to compile the case. After taking some test cases and running the software on them, it may not be the case that the software is not able to give the correct answer. So In the green, we try to pass all the test cases based on different conditions and situations so that in the future it(software) should work on all the cases no matter how hard it is.

3. Refactoring Phase

The Refactoring phase means to optimize and fix the errors if the software has any. Let’s say after running all the test cases we found some errors, they may be syntactical, logical, etc. types of errors, now the question arises of how to correct it. So here the refactoring phase of the TDD helps developers to overcome this situation. The developers try to fix the errors and optimize the code (according to time and space complexity) as much as possible so that it can be as quick as possible. The developers then follow the same phases again starting right from red then green and at last refactoring until all errors are fixed and the code is optimized.

After the refactoring phases i.e. when the code is optimized and the errors get fixed the code again follows the Red green and refactoring phase until and unless it works on all cases properly and correctly.

This can be shown in the image below:

Importance of Test-Driven Development (TDD)

1. Improve Code Quality

Starting with some small unit test cases, you can build the logic of the software you want to implement. By the test cases, the developers can understand the constraints/edge cases and they can write a smooth and good code to implement the software. As stated earlier test cases are significant in the development of any software, the test cases increase the ability of programmers and developers to think of all the edge cases and the hardest situations of the software. Apart from this, By the refactoring phase of TDD, the developers write a well-optimized and clean code which increases the readability of the code and makes it faster.

2. Boost System Design

TDD is a good design technique for software development. By TDD, the developer can easily break the larger problem into smaller components/problems. TDD especially uses a bottom-up approach. The other name of TDD can be given as a test-driven design. Today in this modern era of technology, System design is one of the most important factors that decide the growth of a company i.e., Low-level Design(LLD) and High-Level Design (HLD). TDD helps programmers and developers to make an efficient design with no errors. If such a design is made then it is quite obvious that the demand for that product and software will increase in the market. This helps in the growth of the company and also the net worth of the Company increases.

3. Increase Developer’s Productivity

The developer plays a crucial role in the development of any software, so the developer’s productivity must be at its peak when he/she develops software. By starting with the unit test cases, the developer can easily build the logic and write efficient code to develop it. Now suppose if the code is not working in some cases then it can be determined by TDD before the software is launched. By performing TDD, there are almost no errors left, and the developer’s reputation increases in the company. If you are a developer working in a company and you have not used TDD and say your colleague has used TDD to build software and both of you have submitted the software to the manager then of course the guy that has used TDD will get more credits as compare to that guy who have not used TDD. In an average study in the software domain, TDD increases a developer’s productivity almost 10 times.

4. Reduce Project Costs Over Time

In the beginning stage, it may be the case that a developer is taking more time on TDD but over time when a developer becomes an expert in TDD, then TDD also becomes fast for that developer, and due to this no errors occur in the software and with the lapse of time it saves the project costs of a company and helps the company to earn profit. To understand this Let’s take the example of a payment system in XYZ courses. Suppose a student purchases a course from XYZ and makes the payment and let’s say the developers who have made the payment system had not used TDD when the student purchases the course his/her money will be lost and due to this, the Company’s reputation will be in great danger and due to this the engineers and developers have to work again for that project which will increase the project cost so to overcome the huge cost, developers use TDD before launching the project to not regret later on.

5. Obtain Assistance for Bug Prevention

Bug prevention and debugging are the key aspects of TDD as they focus on the fact that software must be free from errors so that when the software is launched after development the users do not get any problems due to the software. TDD provides fruitful assistance for bug prevention as stated earlier with the help of test cases because TDD is the tool that can provide the sample inputs for the software and it is a tool on which almost all the developers and programmers in the software industry trust.

ERRORS can be fixed only when we have some sample inputs for the code and these sample inputs are provided by TDD.

6. Gain from Lifelong Documentation

For a developer, the test cases obtained from TDD can act as documentation. Whenever a new person goes through that documentation, it will be easy for him/her to understand it quickly. In the software industry, documentation of any project plays a crucial role. Apart from this what matters a lot is how readable the code is in the documentation. With the help of TDD, the developers can create very well documentation in which the code readability is excellent.

7. Create a Maintainable Codebase

As stated earlier, TDD has 3 phases, Red, Green, and Refactoring. In the refactoring phase, the code is optimized to reduce its time complexity and space complexity. This helps in maintaining a good and efficient codebase because It will contain the optimized version of the code with zero errors. Let’s take an example to understand it, say you have used TDD and have included a neat and efficient code for all the cases and you have stored in a codebase and suppose that in the future some new type of bug occurs in the codebase then being an efficient codebase it will be easy to debug the code with the help of TDD. Hence TDD also helps in maintaining a good codebase.

8. Benefit from a Dependable Process

Without TDD, developers lose track of current developments and are unsure how recently developed software will interact with previously flawless code. TDD reduces the defects in the software because it works on the principle of test cases. If the errors are found at the earliest then it helps in creating a dependable codebase and reduces the critical issues in the code. Apart from this it also provides continuous feedback about the status of the code due to which the issues are addressed quickly which contributes to the overall dependability of the development process.

Conclusion

Overall TDD has emerged as a victorious tool in the field of software development. It helps developers fix the issues and errors in their code by unit test cases. Also, it plays a crucial role in the development and progress of a company. No matter whether it is a startup or a top MNC unless and until the company does not use TDD, it will always lag in the market of software. The demand for TDD has increased in the last few years because it is the most powerful tool in the software industry.