Behavior-Driven Development: Definition, Benefits, Examples

What is Behavior-driven Development? Those who regularly work through software must have heard this phrase. BDD was born to solve the problem of understanding, expressing, and ensuring the accuracy of customer requirements and expectations in the software development process. The term represents the process of developing a program based on some basic utilities. So, how does BDD work? What are its key features? Please join Skilltrans to follow the answer revealed right after!

What is Behavior Driven Development?

Behavior Driven Development (BDD) is a software development method that focuses on describing the behavior of the system through understandable scenarios. BDD promotes the use of natural language to express customer requirements and expectations. The platform creates test cases that focus on the behavior of the system instead of just focusing on specific code.

BDD extends Test Driven Development (TDD) but places more emphasis on using natural language to describe requirements. Instead of just writing test code, BDD encourages writing behavioral scenarios that both the development team and stakeholders can understand or participate in.

Where did Behavior Driven Development originate?

Behavior-driven Development (BDD) originated from a software development method called Test-Driven Development (TDD). TDD was developed by Kent Beck in the 1990s and introduced in his book "Extreme Programming Explained" in 1999. TDD writes test cases before writing specific code and then writing code to pass these test cases.

BDD evolved from this approach and is considered an extension of TDD. The foundation focuses on using natural language to describe the desired behavior of the system, thereby creating test cases.

The formal version was developed by Dan North in the early 21st century, then became popular in the Agile and software development community. BDD was born to solve the problem of understanding and expressing customer requirements, as well as expectations more precisely.

The platform focuses on using natural language to describe the desired features and behaviors of the system, thereby creating test cases. This technology ensures that the development team not only understands the customer's requirements but is also able to create specific test cases to check the correctness of the features.

The technology creates consistency in expressing requirements and expectations, thereby the final software product will reflect what the customer expects.

Features of Behavior-Driven Development

By BDD, teams can improve the quality of their software, reduce the risk of defects, and deliver value to customers more efficiently.

Use of natural language

One of the first important features of BDD is the use of natural language to describe the desired modes and behaviors of the system. 

Using natural language makes it easier for everyone, including non-technical members of the team such as the business team or customers to understand and express requirements or expectations about the system clearly. So, everyone can actively participate in describing requirements and expectations, no longer limited by technical skills or specialized knowledge.

Test Automation

Test automation saves time and effort compared to manual testing while minimizing human errors during the testing process.

Test cases on the behavior of the system can be easily integrated with automated test management tools such as Selenium, JUnit, or other testing tools. The platform makes the testing process more flexible and easy to manage.

Additionally, test automation creates quick feedback from actual testing, thereby helping to detect and fix errors flexibly and promptly.

Fast Feedback

Users will receive many benefits from the foundation of fast feedback.

Identify basic operational options BDD helps detect errors early in the development process, from writing user stories to automating testing. The technology detects and resolves problems early, helping to reduce costs and time to fix errors later.

When errors are detected, the foundation easily adjusts and modifies the usage scenarios or test cases to reflect the changes. The technology supports a more flexible development process.

Steps in implementing Behavior Driven Development in software development projects

These steps foster collaboration, clarity, and test-driven development throughout the software lifecycle.

Step 1: Identify customer requirements

Goal: Clearly identify customer requirements, so all stakeholders have a common view of what needs to be developed.

Analysis:

• Communication and collaboration: You need close communication between the development team, testers, and customers. Through meetings or interviews, requirements are gathered and clarified. The goal is to understand what the customer wants and how they will use the product.

• Ask open-ended questions: To gain detailed information, the team needs to ask open-ended questions that encourage customers to explain their needs fully. These questions can be related to specific scenarios in which they will use the product.

• Take notes and summarize requirements: After gathering information, the team needs to take notes and summarize the requirements into a clear and controllable list. It facilitates the conversion of the requirements into BDD scenarios in the next step.

Step 2: Write BDD scenarios with Gherkin

Goal: Convert the identified requirements into specific and understandable BDD scenarios using Gherkin syntax.

Analysis:

Gherkin Scenario Structure: BDD scenarios are written in natural language in the “Given, When, Then” format, which describes a specific situation that a user will encounter.

• Given: Initial state or precondition.

• When: Action or event that occurs.

• Then: Expected result from that action.

Using Gherkin not only helps create test documentation but also makes it easy to understand and edit for non-technical people, increasing transparency and facilitating the participation of all stakeholders.

Step 3: Implement automated testing

Goal: Automate testing of written BDD scenarios to detect errors quickly and reduce testing time.

Analysis:

• Choosing an automated testing tool: There are many tools that support BDD such as Cucumber, SpecFlow, or Behave. With these tools, the development team can automate written BDD scenarios.

• Test Creation: Gherkin scenarios are converted into test code in the chosen tool, which includes defining specific steps to check the conditions described in the scenario.

• Automated Test Execution: When the source code is changed or updated, automated tests are run to check that the scenarios are executed correctly to detect errors immediately and minimize risks during the development process.

Step 4: Scenario-Based Feature Development

Goal: Build software features based on defined BDD scenarios. The purpose is the final product meets user requirements.

Analysis:

• Scenario-Based Development: The development team will work to build source code for features based on the written BDD scenarios. Each new feature developed will be tested using automated tests that the team has set up.

• Stepwise Programming: By developing each feature based on scenarios, the development team can easily track and test the feature against the defined requirements. If there are any errors, they will be detected immediately through automated tests.

• Continuous Improvement: After each test, if there are any changes in the requirements or if the users have new feedback, the team can quickly update the scripts and source code, creating a continuous improvement process, helping the product develop in the expected direction.

Behavior-Driven Development Testing Tools

BDD tools offer a structured framework for writing and executing tests based on user stories and scenarios. Here are some popular BDD tools:

• Cucumber: Cucumber is one of the most popular tools supporting BDD and can be used for many programming languages.

• SpecFlow: SpecFlow is a version of BDD for .NET, permitting Gherkin scripting and easy integration of testing into .NET projects.

• Behave: Behave is a BDD tool for Python, supporting scripting and automated testing.

• Integration with CI/CD: BDD can be easily integrated into the continuous integration (CI/CD) process, contributing to the software is always of high quality when released.

Advantages of applying BDD in Software development

Adopting BDD delivers higher-quality software, improves collaboration, and reduces development time.

Increased understanding between parties

BDD creates an effective communication bridge between development, testing teams, and customers through the use of natural language in describing requirements.

• Clear communication: BDD scenarios are written in understandable language. So, all stakeholders, even those with non-technical backgrounds, participate in the development process. It minimizes ambiguity and misunderstandings, resulting in everyone having the same view of the project.

• Discussion and clarification of requirements: BDD encourages discussions between stakeholders to clarify requirements and expectations. When customers, developers, and testers are involved in the scripting process, they have the opportunity to give their opinions and discuss what is needed for the product.

• Living Documentation: BDD scripts are not only requirements documents but also test documents, easy to update and use throughout the development process.

Improve Development Efficiency

Applying BDD not only helps to reduce errors but also improves overall development efficiency.

• Test Early and Continuously: The development team can test features as soon as the source code is written to detect errors early, reduce repair costs, and increase development efficiency.

• Structured Development Process: BDD creates a clearly structured development process. Each feature is built based on defined scenarios. So, the development team has a better grasp of what needs to be done, and it makes better planning and time management.

• Automated Integration: Integrating BDD with automated testing tools to run automated tests every time there is a change in the source code. It reduces the workload for testers and they will focus on more complex test cases.

Create products that match the end user's desires

BDD aims to develop products that meet the needs and expectations of the end user.

Modeling user behavior: BDD encourages the development team to model user behavior through specific scenarios. When these scenarios are built based on real user needs, the developed product will accurately reflect how users will interact with it.

Quick feedback: The customer can join the scenario writing process, they will have the ability to provide quick feedback on requirements and expectations. If anything is unclear or needs to be adjusted, the team can quickly adjust the scenario and develop the feature accordingly.

Product quality assurance: Automated tests based on BDD scenarios help the final product work as expected. The final product reduce errors, increase end-user satisfaction as they feel the product meets their needs.

Disadvantages of applying BDD in Software development

Using BDD requires programmers to understand the process and how to write effective test cases. To approach the technology, programmers can consider more information in the beginning.

To effectively implement BDD, an organization needs a solid foundation, including support from members of the organization and investment in development tools and processes.

Tips for getting started with BDD

Here are some tips to help you implement BDD in your projects and reap the benefits from it.

Choose the right tool for your ecosystem

Align the tool choice with your team's technical expertise and project requirements to smooth adoption and implementation.

Evaluate project requirements

Before deciding which tool to use, the development team needs to evaluate the specific requirements of the project. Factors such as programming language, application type, project size, and the technology used will influence the choice of tool. 

Each BDD tool is usually compatible with certain programming languages. For example, Cucumber is commonly used with Ruby, Java, and JavaScript, while SpecFlow is primarily for .NET. Choosing a tool that is compatible with the development language will help the integration process go more smoothly.

Features and Extensibility

It is necessary to consider the features that the tool provides as well as its extensibility. A good tool should not only meet current requirements but also be scalable to serve future needs. BDD tools should support easy scripting, integrated test automation, and have clear documentation.

Integration with the Existing Process

The selected BDD tool should also be able to integrate easily with the current development process from the ability to integrate with source code management systems, CI/CD tools to other testing frameworks. The tool should support integration into the existing workflow without major changes. Smooth integration for the team maintains productivity and does not disrupt the development process.

Building a BDD culture

You need to build a sustainable BDD culture that enhances collaboration and product quality.

Encourage participation from all stakeholders

Building a BDD culture is the effort of the development team, testers, customers, and other stakeholders. One way you should do is to organize training sessions to make everyone understand BDD, how it works, and the importance of writing behavioral scenarios. Training can help people feel more confident in participating in this process.

Create a collaborative environment

BDD is based on communication and collaboration between stakeholders. A working environment that encourages information exchange will facilitate the implementation of BDD. The development team should hold regular meetings to discuss requirements, scenarios, and customer feedback to clarify requirements and also create space for creativity and innovation.

Encourage initiative and responsibility

In a BDD culture, people should be encouraged to actively participate in scripting and testing, which not only increases their responsibility but also helps create diverse scenarios that more accurately reflect user needs.

Continuous evaluation and improvement

A BDD culture should be continuously evaluated and improved. The team should regularly review the effectiveness of the scripts and testing process by creating a mechanism to collect feedback from customers and stakeholders on the product and development process. This feedback should be used to adjust and improve the BDD scripts and workflow.

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Conclusion

Behavior Driven Development (BDD) is a powerful and effective approach to software development that improves communication, reduces errors, and improves product quality. Applying BDD benefits not only the development team but also the customer, ensuring that the final product meets user expectations. 

The world of technology is constantly changing, one way for you to quickly update is to continuously learn. You can refer to Skilltrans courses to firmly step on your career path.