BDD vs. TDD – Key differences you must know

One may ask the question, what is BDD vs. TDD? Behavior-driven development (BDD) and test-driven development (TDD) are two popular software design methodologies often used interchangeably. However, they are not the same. BDD focuses on the design of desired behavior, whereas TDD focuses on designing individual units of code to meet desired behavior. This article will cover the key differences between BDD vs TDD.

Defining BDD

BDD, or Business Driven Development, is an agile framework that focuses on the business benefits of the product. It is one of the most popular design frameworks used in software development.

BDD is about creating automated test cases to ensure that the requirements are met before coding starts. It also encourages collaboration between developers and stakeholders to ensure that these requirements are delivered successfully.

Defining TDD: 

TDD is a programming technique that stands for Test-Driven Development in software development. Essentially, it helps programmers identify and fix errors made by developing the system in stages. This decreases the number of errors to be found by testing the finished product. TDD is a prevalent technique for producing high-quality code with low levels of bugs and errors.

BDD vs. TDD: Understanding the key differences

TDD and BDD are two agile software development methods that share many similarities. They both focus on incremental and iterative development, emphasizing testing and debugging. They both require the creation of automated tests for each user story. The difference lies in how they are executed, what they are written for, which one is the preferred method, and when to use one over the other. So let us understand the key differences that you must know:

Because unit tests are technical, TDD restricts readers and writers to just developers and testers. Behavioral tests are frequently prescribed by persons who know the client better, such as the product owner or manager, in BDD. Because behavioral tests are written in simple English, they can be read and assessed by almost anybody, including stakeholders, business owners, product managers, developers, and testers.

TDD is also faster than BDD, which necessitates more setups before testing. Mocks can be used instead of true dependencies in unit testing, and mocking frameworks can help developers save even more time. Furthermore, in TDD, developers may readily and quickly find problems; in BDD, however, behavioral tests can signal a programme malfunction but not the particular section of the code that fails.

The greater the number, the easier it will be to maintain in the future when it comes to code coverage. Code coverage in unit testing, on the other hand, should rarely exceed 90%. However, code coverage is often higher in behavioral tests, even reaching 100%.

Behavioral tests are easier to maintain in the future due to their high-level nature, which means there will be fewer modifications to the tests because not every change in the code will influence the software behavior. On the other hand, unit tests will need to be updated whenever the code is modified. Unit tests are also particular to the code they cover; for example, changes in the programming language or framework will cause unit tests to change. Even though the application’s language has changed totally, behavioral tests will remain the same in BDD.

Conclusion: The best practice is to combine the two ways because they complement each other well. Behavior Driven Development, which uses behavioral tests as building blocks, will aid us in developing a product that provides the correct value to the user while avoiding superfluous code. On the other hand, unit testing will increase the product’s quality because flaws will be identified and corrected sooner rather than later, when more layers have been added to the architecture.