Engineering

Behavior-Driven Development (BDD)

A software development process that focuses on the collaboration between developers, testers, and business stakeholders to ensure that the software meets the needs of the customer.

Also called: BDD, Behavior Driven Design, Behavior Driven Engineering, Behavior Driven Testing, and Behavior Driven Software Development

See also: Acceptance Criteria, Acceptance Test Driven Development, Acceptance Test, Agile Definition of Done, Agile Framework, Agile Manifesto, Agile Principles, Agile Product Development, Product Delivery, Product Manager

Relevant metrics: Test Coverage, Test Execution Time, Number of Defects, Number of Automated Tests, and Number of Manual Tests

In this article

What is Behavior-Driven Development

Behavior-Driven Development (BDD) is a software development methodology that focuses on the behavior of an application. It is an extension of Test-Driven Development (TDD) and is based on the principles of communication, collaboration, and automation.

BDD encourages teams to define the behavior of an application through examples, which are then used to create automated tests. This helps to ensure that the application meets the desired behavior and that any changes made to the code do not break existing functionality. BDD also helps to ensure that the application is easy to maintain and understand.

Where did Behavior-Driven Development come from?

Behavior-Driven Development (BDD) is a software development methodology that was first introduced in 2006 by Dan North. It is an extension of Test-Driven Development (TDD) and is based on the principles of Domain-Driven Design (DDD). BDD is a process that focuses on the behavior of an application, rather than its implementation. It is used to create a shared understanding of the application’s behavior between the development team and the stakeholders. BDD is a collaborative process that involves the stakeholders, developers, and testers in the development process. It is used to ensure that the application meets the requirements of the stakeholders and that the development team is able to deliver a quality product.

A Tool for Enhancing Software Quality

BDD is based on the idea that software should be developed in a way that is driven by the behavior of its users. This means that the development process should be focused on understanding the behavior of the users and how they interact with the software. This helps to ensure that the software meets the needs of its users and is of high quality.

BDD also encourages collaboration between developers, testers, and business stakeholders to ensure that the software meets the expectations of its users and is of high quality. By working together, developers, testers, and business stakeholders can ensure that the software meets the needs of its users and is of high quality.

The use of BDD helps to ensure that the software is of high quality and meets the expectations that was intended. It is an agile process that encourages collaboration between developers, testers, and business stakeholders to ensure that the software meets the needs of its users.

The Two Main Parts of BDD

The BDD approach can be divided into two main parts:

  • The practice of using examples written in a shared language to illustrate behaviors (how users will interact with the product).
  • The practice of using these examples as the basis for automated tests. This ensures that the system works as defined by the business throughout the project’s lifespan, as well as checking functionality for the user.

Software development is a way of supporting human behavior through automation, replacement or creation. Every change in behavior should help the business or company achieve its goals, whether that’s increasing revenue, improving usage or reducing waste. BDD proposes that in order to meet business requirements, you need to understand what the software should achieve from a business perspective. This then becomes the business goal: the driving force behind the project.

Writing BDD test cases

BDD testing revolves around the “given-when-then” structure.

  • Given (Context)
  • When (Action)
  • Then (Outcome)

In addition to that, you can use And after any of the descriptors if you require more information in a scenario.

  • Given (context),
  • And (some more context),
  • When (action/event),
  • And (further action/event),
  • Then (outcome)
  • And (further outcome)

Teams construct test scenarios using a clear, comprehensible language and monitor their progress with ease. By adopting this approach, engineers can translate business requirements into the correct software implementation, fostering greater collaboration among stakeholders. BDD testing also allows non-technical team members to stay informed about the software project’s progress, fostering transparency and collaboration.

Key Characteristics of BDD Testing

  • Tests are written in a human-friendly, descriptive language.
  • Tests are user-centric, focusing on the end-user experience.
  • Tests are derived from spec files, which accelerates the development process.

Advantages of Behavior-Driven Development

  • Improved Collaboration. Behavior-Driven Development (BDD) encourages collaboration between developers, testers, and stakeholders. This helps to ensure that everyone is on the same page and that the end product meets the needs of all involved.
  • Increased Efficiency. BDD helps to streamline the development process by focusing on the behavior of the system rather than the implementation details. This allows developers to quickly identify and address issues, resulting in faster development cycles.
  • Improved Quality. BDD helps to ensure that the end product meets the requirements of the stakeholders. By focusing on the behavior of the system, developers can ensure that the system is functioning as expected and that any issues are quickly identified and addressed.
  • Reduced Costs. By streamlining the development process and ensuring that the end product meets the requirements of the stakeholders, BDD helps to reduce development costs. This can result in significant savings for organizations.

Challenges of Implementing Behavior-Driven Development

  • Difficulty in Establishing Clear Goals. Behavior-Driven Development (BDD) requires that developers and stakeholders agree on the desired behavior of the software before development begins. This can be difficult to achieve, as stakeholders may have different ideas of what the software should do.
  • Complexity of Writing Tests. BDD requires that tests be written in a specific format, which can be complex and time-consuming. Additionally, tests must be written for every behavior that is expected of the software, which can be a daunting task.
  • Difficulty in Debugging. BDD tests are written in a specific format, which can make debugging difficult. Additionally, if the tests are not written correctly, it can be difficult to identify the source of the problem.
  • Time-Consuming Process. BDD is a time-consuming process, as tests must be written for every behavior that is expected of the software. Additionally, the tests must be written in a specific format, which can be time-consuming.
Relevant questions to ask
  • What is the purpose of using BehaviorDriven Development?
    Hint The purpose of using Behavior-Driven Development (BDD) is to create software that is more reliable, maintainable, and easier to understand by focusing on the behavior of the system rather than the implementation details.
  • What are the benefits of using BehaviorDriven Development?
    Hint The benefits of using BDD include improved communication between stakeholders, increased collaboration between developers and testers, and a more efficient development process.
  • How will BehaviorDriven Development help me achieve my goals?
    Hint BDD can help you achieve your goals by providing a common language for stakeholders to communicate their requirements, allowing developers to focus on the behavior of the system rather than the implementation details, and providing a framework for testing the system.
  • What are the risks associated with using BehaviorDriven Development?
    Hint The risks associated with using BDD include the potential for misunderstandings between stakeholders, the need for additional training for developers and testers, and the potential for increased complexity in the development process.
  • What are the best practices for using BehaviorDriven Development?
    Hint The best practices for using BDD include creating a shared understanding of the system's behavior, using a common language to describe the behavior, and creating automated tests to ensure that the system behaves as expected.
  • How will I measure the success of my BehaviorDriven Development project?
    Hint You can measure the success of your BDD project by tracking the number of bugs found during development, the amount of time saved during development, and the number of features implemented.
  • What resources do I need to successfully implement BehaviorDriven Development?
    Hint The resources you need to successfully implement BDD include a shared understanding of the system's behavior, a common language to describe the behavior, and automated tests to ensure that the system behaves as expected.
  • How will I ensure that my team is following the BehaviorDriven Development process?
    Hint You can ensure that your team is following the BDD process by providing training on the process, setting up a system for tracking progress, and regularly reviewing the progress of the project.
People who talk about the topic of Behavior-Driven Development (BDD) on Twitter
Relevant books on the topic of Behavior-Driven Development (BDD)
  • Introducing BDD by Dan North (2006)
  • Specification by Example by Gojko Adzic (2011)
  • The Cucumber Book by Matt Wynne and Aslak Hellesøy (2010)
  • Living Documentation by Liz Keogh (2016)
  • Integrated Tests Are A Scam by J. B. Rainsberger (2003)

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