BDD

Behavior Driven Development (BDD) represents a new perspective in the realm of software development, particularly in testing. This paradigm not only focuses on writing and executing tests but also on understanding them and communicating among all stakeholders involved in the development cycle. BDD emphasizes a common language shared among developers, testers, project managers, executives, and clients, thus contributing to the creation of living and understandable documentation regarding the expected behavior of software.

In this perspective, one admires the peculiarity of BDD tests, which are written in natural languages such as English or Italian. The specification of these tests utilizes the Gherkin syntax, which describes the expected behavior of the software in a readable and understandable format for all parties involved in the project's development. Therefore, it allows easy interpretation by both non-technical individuals such as project managers, clients, and executives, and technical individuals such as developers and testers.

The Gherkin syntax is structured to follow a common pattern, with predefined keywords indicating the nature of the instruction. The main keywords include "Feature," which defines a functionality or aspect of the system being tested; "Scenario," representing a single test case describing the system's behavior in a particular situation; "Step," a step in the Scenario representing an action. Actions are defined using the keywords "Given," "When," "Then," respectively used to define the initial state of the system, the actions to be taken, and the final state, thus assertions and verifications executed at the end of the test case. This results in tests specified as the following:

Feature: User Registration 
    Scenario: Successful Registration 
        Given the user is on the registration page 
        When the user enters a valid email and password 
        And clicks the registration button 
        Then the user should be successfully registered

Once the test case is defined, it is necessary to implement the step instructions using the programming language of the system under test. This practice enables the reuse of actions within other test cases, avoiding the need to reimplement them from scratch. This significantly contributes to reducing the costs associated with creating new test cases.

This approach fosters collaboration and mutual understanding among the different involved parties, thus mitigating expression difficulties between technical and non-technical individuals. It allows for a clear vision of the software's objectives, behaviors, and requirements.

Each actor involved in the development cycle has different needs and approaches to this type of testing. Developers can use BDD tests to understand the system requirements clearly and precisely because these tests address specific usage scenarios and their expected behaviors.

Testers can use them to specify additional test cases based on the product's main requirements or by combining various steps differently to further stimulate the system through the specification of new tests.

Project managers can use this type of test to gain insight into development progress, enabling them to make decisions and organize the process effectively. If an agile development methodology is adopted, a project manager could monitor the completion status of features related to a sprint directly based on the system's BDD test status.

Moreover, executives can verify if the product meets the requirements and expectations based on these tests or use them to communicate easily with clients and project managers.

Lastly, clients benefit from this as they can receive updates on the product's status by analyzing test statistics and reports created, thus obtaining tangible information to support choices regarding the project's lifecycle.