Test Driven Development (TDD) in Agile : Steps and Benefits

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by StarAgile

September 21, 2021
Category Project Management


WHAT IS TDD IN AGILE?

TDD in agile is a framework that emphasizes the creation of unit test cases prior to writing the real code. It is an iterative process that incorporates programming, unit testing, and refactoring. It is inevitable for mistakes to occur throughout the design and coding phases of software development. In most cases, these errors are corrected through feedback. Because of the late feedback, modifications may be heaped atop faulty code, leaving no obvious underlying cause.

Agile development needs frequent input in order to produce the desired output. In simpler words, Agile development may also be referred to as Feedback Driven Development. There is a good chance that project requirements may change during the sprint development cycle. To address this and to ensure that products remain aligned with changing customer needs, teams require regular input to prevent delivering useless software. TDD's agile approach is designed to provide this type of feedback early on. Agile teams frequently employ test-driven development techniques such as test-driven systems development, acceptance test-driven development, and behavior-driven development. Agile teams employ these techniques to validate code at various stages and stages of development. Each approach has a unique combination of benefits and disadvantages and is extensively evaluated before developing any code. 

The TDD technique is based on the ideas of the Agile manifesto and Extreme programming. As the name implies, the test process is at the heart of software development. Additionally, it is a structural approach that helps developers and testers to obtain optimized code that demonstrates long-term resilience. TDD requires developers to begin by building tiny test cases for each feature based on their first comprehension. This technique's major goal is to alter or create new code only when the tests fail. This eliminates the need for duplicate test scripts. Agile testing guarantees that business value is given to the client at regular intervals while working at a sustainable pace, as opposed to traditional testing. Numerous test approaches are included, including the construction of test cases and their execution prior to the creation of code. 

If you'd like to be a certified Professional Agile practitioner, you may enroll in a variety of Agile courses. The PMI-ACP is one of the most well-known courses; it is given by the Project Management Institute and now you can even opt for PMI-ACP training online.

The PMI-ACP course encompasses agile methods, tools, and techniques and includes case studies.

WHO CAN IMPLEMENT TDD & OTHER AGILE TESTING METHODOLOGIES

Agile development's growth has resulted in the introduction of several pragmatic methods for rapidly producing high-quality software. As a result, the organization's function as a Professional Agile Practitioner is critical.

Agile practitioners are a crucial factor in the Agile transformation process. They apply their experience to advise teams on Agile best practices and to help them through the process of implementing their new approach. Agile practitioners are responsible for determining which Agile techniques are most appropriate for a particular organization. They will analyze the team's existing operating model and identify opportunities for improvement. 

\Additionally, they will evaluate potential advantages and disadvantages prior to assisting the team in implementing a suitable framework. The objective of an Agile practitioner is to ensure that businesses completely embrace Agile in order to reap all of its benefits.

Steps of Test Driven Development

Following constitute of the TDD flow:

  • Read, understand and act on requests for features or problems.
  • Write a test unit for translating the requirement. If you have enabled hot reload, the unit test will start but fails since no code has yet been implemented.
  • The needed code is created and implemented. All tests should pass; repeat this step if not.
  • Reflect your code to make it easier to read.
  • Repeat, lather, and again repeat.

The above-mentioned flow can be executed in 3 steps;

Step 1: The red phase shows that the code does not function properly.

Create a unit test for the function you're going to build; the unit test should be concise and focus on a single aspect of the function's behavior.

Write only the minimum amount of code necessary to ensure that it compiles.

Conduct the exam. It ought to fail. By writing a failed test, you can check that your test is calling the proper code and that it is not operating by accident. This is a significant failure, and you anticipate it.

Step 2: The green phase: This phase indicates that all is OK, but not optimally.

Create the very minimal amount of code required to pass the test.

If the test passes as anticipated, you are finished with that section of code. You do not need to develop additional code that is ambiguous.

Rerun your test and verify that it passes. This will display a green progress bar.

Step 3: The Blue Phase/Reworking: This shows that the tester is refactoring the code but is sure that their code is covered by tests, allowing them to alter and enhance our code.

After passing your test, you may now refactor without fear of breaking anything. Examine the code and make any necessary changes to maintain it clean.

Eliminate duplication introduced by the new feature.

Modify the design to enhance the overall solution.

Following each refactoring, restart all tests to ensure they continue to pass.

TDD APPROACH IN AGILE

The "Test-First" philosophy, in which unit tests are created before code, can help alleviate constraints that hamper the delivery of quality. The test contributes to the definition of what the code is intended to perform by offering direction to the developer regarding user functions.

TDD's test-first methodology also aids in mitigating significant bottlenecks that impede software quality and delivery. The system changes in response to continuous input, problem patches, and the inclusion of new features, ensuring that everything functions as planned. TDD fosters collaboration between members of the development and quality assurance teams, as well as with the client. Additionally, because the tests are generated in advance, teams save time by not having to recreate lengthy test scripts.

A PMI-ACP certification can assist you in demonstrating your Agile expertise and honing your abilities.

PMP Certification

BENEFITS OF TEST-DRIVEN DEVELOPMENT (TDD)

Delivering high-quality goods necessitates not just debugging but also process improvement. When properly implemented, the TDD technique has several benefits, most notably in terms of long-term cost savings and delivering genuine value to organizations.

  • Promotes the development of efficient code. - Assists developers in better analyzing and comprehending customer requirements, as well as requesting clarification when they are not sufficiently specified.
  • In the later phases of development, adding and testing new capabilities becomes easier.
  • Test coverage is significantly higher in TDD than in conventional development approaches. This is because TDD emphasizes the need of building tests for each functionality from the start.
  • Enhances the developer's productivity and results in the creation of a versatile and easy-to-maintain codebase.

FRAMEWORKS FOR TEST DRIVEN DEVELOPMENT (TDD)

Numerous frameworks exist that allow test-driven development and are based on distinct programming languages. Several prominent ones are listed below.

  • PHPUnit: This is the unit testing framework for PHP programs.
  • PyUnit and DocTest: Two popular Python unit testing frameworks.
  • TestNG: A second widely used Java testing framework. This framework circumvents Junit's restrictions.
  • Rspec: A framework for testing Ruby programs.
  • Junit: A widely used Java unit testing tool.
  • csUnit and NUnit: Both are free and open-source frameworks for unit testing.NET apps.

Final thoughts

The PMI-ACP training enables you to develop into a proficient agile professional with an in-depth understanding of a variety of agile techniques. The ACP (Agile Certified Practitioner) credential is PMI's fastest-growing, and the PMI-ACP training exam was recently revised to include the Agile Practice Guide.