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A Quick Guide: Test Driven Development (TDD): Life Cycle in Steps & Advantages

By December 7, 2021August 21st, 2023No Comments10 min read
TDD Life cycle

Building tests before developing code is an element of the Test-Driven Development technique, which is a popular Agile software development strategy. The developer’s main task here is to write a test for the required function and then write production code to pass it. Software testing is an important part of the software development life cycle and Test-Driven Development, as early detection of faults and vulnerabilities is critical for improving product quality.

As a result, software testing should be prioritised in order for the product to speak for itself in terms of quality. This strategy has been found to be helpful in preserving software quality because it prioritises requirements, which helps developers avoid issues like “gold plating,” which involves adding superfluous features and capabilities to fulfil the developers’ expectations rather than the customers’.

We’ll look at how TDD may be used at every stage of the development process, from unit testing to deployment, in this post. You’ll discover several tips, capabilities, advantages and tactics for efficiently using TDD, as well as some typical mistakes to avoid when doing so. Let the learning begin and start with What is TDD and why it is used.

Why TDD is Important in Modern Development?

What if you could design a better, more sophisticated app by using effective testing? How would you like it if you could come up with a method that practically eliminates the need for debugging while simultaneously alerting you to programming problems as soon as they occur?

Because it aids in the early detection of coupling, TDD helps developers to design and automate tests to ensure the functionality of the programme they’re working on. Developers use object-oriented design strategies to produce code that is less coupled and simpler to test. They only write verified code to keep things clean and simple, reduce defects, and speed up development. Test-driven development is gaining traction, and there’s plenty of data to back it up. TDD reduces the number of production problems while simultaneously enhancing the quality of the code It improves the readability and manageability of code, to put it another way. It also incorporates automated regression testing.

TDD has been around for almost two decades. Programming is a challenging endeavour and it takes months or years of consistent effort to become proficient at it. At best, the faults of the software development team result in non-compilable source code. These flaws, in the worst-case situation, cause the most serious issues. Extreme programming, which strives to increase software quality and responsiveness, was originally tied to TDD. TDD is the ideal strategy when starting a new software project or need to rebuild outdated software into a contemporary and efficient solution for your organisation. In recent years, however, it has gained appeal as a stand-alone strategy for increasing development team productivity and producing better code.

What are the Steps of Test Driven Development (TDD)?

Owing to the various stage of the tests inside the TDD life cycle, this approach is commonly referred to as Red-Green-Refactoring.

Let’s explore test driven development life cycle steps: –

  • Think & write test cases
  • Red – Failure of test case
  • Green – Code and get the new test case pass
  • Green – Ensure all old test cases also pass
  • Refactor the code to clean it
  • Repeat this cycle

Think and write the test case: Steps in test driven development start with writing a test. During TDD approach, Almost all tests should define a function. To build an effective test, the software developer must first comprehend the project’s needs and specifications. The developer develops the test case with no code in front of him during this step. This is not to be mistaken with a unit test, which is carried out after the code has been developed. Before developing any code, TDD allows the developer to focus on the system requirements. This is challenging, but it ensures that the developer understands the needed functionality and builds the test case accordingly. The test case isn’t twisted to show that the code works; instead, it’s used to ensure that the required functionality is there.

Red – Test case failure- During TDD testing, This step guarantees that the automated test framework functions properly, that new tests do not pass without requiring new code, and that new tests do not always pass. The new test should not fail in an unexpected manner. At this point, you try to execute the test case. Because there is no code, you will receive a compilation error. This is known as the Red stage, and it denotes that the test case failed.

Green – Observing the code that allows the test to pass Keep in mind that the code’s purpose is to pass the test, even if the written code isn’t ideal. The code must not exceed the functionality of the test. The developer builds the bare minimum of code to pass the previously failed test case. This is a challenging method for developers who are used to writing code for full modules at once. The concept of “just enough” code can help with quality assurance.

Green – Verify that all previous test cases pass to clarify, developer must ensure that no old test case fails while testing newly developed code. This is nothing more than a regressive cycle. If the test cases produced in the previous steps all succeeded, the programmer may be certain that the new code satisfies the test requirement. If the intended outcomes are not achieved, the programmer must continue to rework the code until they are.

Refactor the code to make it cleaner: In TDD, refactoring is critical. Once the test is passed, the new code will be moved from a convenient area where it was tested to where it belongs naturally. Any duplicate code must be removed to avoid confusion. Variables, objects, classes, and methods should all be named appropriately to represent what they truly mean, since it may be necessary to provide some degree of abstraction for your code to be reusable and manageable. At this point, the developer refactors the code to verify that it is still functional and polished. Steps 3 and 4 are entirely focused with the production of code, with minimal attention paid to other important factors such as efficient design, maintainability, and so on.

Rep the above steps: Steps 1 to 5 are automated and executed numerous times to ensure that all features are covered in TDD cycles.

Read Also: Top DevOps Best Practices to Strategic Continuous Testing in 2022

What is Test Driven Development (TDD) in Agile?

TDD (Test Driven Development) is a software development methodology that demands the creation of unit tests prior to the code they are meant to assess that adheres to the agile approach of iteratively developing software with clean, simple designs and code.

TDD, which originated in the Agile arena, is now widely acknowledged as a discipline in its own right, with applications outside of the agile setting.

To produce the desired product, agile development need constant input, hence, Agile development can also be referred to as Feedback Driven Development.

During the development sprint cycle, there’s a good chance that project requirements may change. To cope with this and produce solutions that are aligned with the changing needs of clients, teams require frequent input in order to avoid delivering unsuitable software. TDD is designed to provide this type of early feedback.

Unit Testing

Because of the TDD technique, unit testing has changed dramatically with the emergence of agile development methodologies such as XP (eXtreme Programming). TDD is a software development approach in which unit tests are used to drive the development process. It may also be viewed as a thinking process that results in unit tests, and thinking in tests leads in more extensive testing and an easier-to-extend software architecture.

Unit testing is the process of writing multiple little tests that each test one very simple function or object behaviour, whereas, TDD refers to how and when you test. They are diametrically opposite to one other.

An individual unit of behaviour is the smallest unit of behaviour that may be examined separately. Before, after, or during the development of a programme, unit tests can be developed. TDD is a thought process that results in unit tests, and “thinking in tests” results in more fine-grained and thorough testing, as well as a more extendible software architecture.

It is vital to involve the QA team at every stage of the TDD process, whether it is creating unit tests or performing unit tests earlier in the process, which occurs at the end of a block of work and only captures end-to-end occurrences. QA test the system from start to finish to have a better knowledge of the entire system. To include unit testing into the application’s essential functioning, the QA team should engage with the developer.

What are the Benefits of Test-Driven Development (TDD)?

There is a common misconception that TDD takes longer and costs more money. However, based on industry experience, this is only true in the short term. The TDD approach has obvious long-term benefits, which appeal to both customers and developers. Here we are listed top benefits of TDD.

Improved programme design and code quality:-

When writing tests, programmers must first define what they want the code to do. When it comes to changes, organised code is much simpler to work with since TDD encourages developers to write code that is cleaner, more readable, and manageable. Developers save time and effort by focusing on smaller, more digestible code chunks, which also makes it easier to satisfy test requirements. Clean code is especially important when responsibilities are transferred between different members of the product team. Developers estimate how it will interact with other portions of the code as well as the experience it will deliver. 

TDD improves the documentation of the code :-

When using this method, there is no urgent need to spend time producing extensive and time-consuming documentation that is difficult to maintain. To guarantee that the unit test is complete and acts effectively, programmers start with user stories. The results are straightforward and consistent, getting the code as close to meeting all of the criteria as possible. Because there are so many simple unit tests, they might be used as documentation to show how the code should work. It also allows programmers and testers to devote more time and resources to their core responsibilities.

Refactoring code goes more smoothly :-

One of the most significant benefits of test-driven development is that it makes the code much easier to manage. TDD also helps to reduce the overall number of hours spent on testing and maintenance tasks. According to several researches, application maintenance takes twice as long without TDD as it does with TDD-enabled software development lifecycles. It’s common knowledge that online and cross-platform apps like PWAs that use Test Driven Development take longer to develop than those that don’t. According to other reports, the difference is almost 30%.

What are the Disadvantages of Test-Driven Development?

TDD, like any other software development process, has limitations that might make it difficult for teams to use it. Here we are listed disadvantages of test driven development.

The development process is slowed by TDD :-

If you’re short on time and need to get your product or service out the door fast, TDD might not be the greatest option. Because a team will be busy building tests initially, the implementation code may not be available on time and TDD is commonly believed to take longer and so cost more, however our experience demonstrates that this is only true for short-term projects. TDD will be helpful in the long run, when the number of sprints reaches double digits, in terms of quality, money, and speed

Supporting and maintaining TDD is difficult :-

This is without a doubt one of TDD’s most serious flaws. When a product’s specifications change, the testing must shift as well. When a product’s specifications change, the testing must shift as well. After that, you’ll have to change the code to fit the new tests. With any development paradigm, fundamental requirement changes are costly, but in TDD, these scope modifications may have a significant influence on timeframes. After that, you’ll have to change the code to fit the new tests. With any development paradigm, fundamental requirement changes are costly, but in TDD, these scope modifications may have a significant influence on timeframes.

Conclusion: –

Because it is used for more than merely verifying accuracy, Test Driven Development produces the greatest results when the code is modified on a regular basis. It may also assist in the construction of software frameworks. TDD results in code that is more modularized, adaptable, and extendable. TDD is a wonderful match when you need to create a pure logic function. When the task you need to perform has a well-defined set of expected inputs and outputs, it’s a smart idea to utilise TDD to construct your tests and code. After reading this blog article, you will have a better knowledge of TDD’s idea and will be able to apply it to your software development process.

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