Understanding Behavior Driven Development Testing

Testlio

October 4th, 2024

Behavior Driven Development (BDD) testing addresses these issues by using simple language for test cases, making them understandable even to non-technical stakeholders. This approach improves collaboration between the technical and business sides of an organization.

Interestingly, market research predicts a significant rise in the adoption of BDD tools from 2022 to 2029. Companies of all sizes are adopting this trend, recognizing the value BDD brings to their development processes.

In this article, we’ll explore behavior driven development testing, covering its basics, advantages, challenges, processes, tools, and role in agile and continuous delivery. We’ll also highlight the importance of testing on real devices.

What is Behavior Driven Development Testing

Behavior driven development testing is an approach to software development that promotes collaboration between developers, testers, and business stakeholders. It uses the principles of test-driven development (TDD) and acceptance-test-driven development (ATDD) by focusing on how the software behaves from a user’s point of view.

Using BDD, non-technical stakeholders can understand and contribute to the development process using natural language constructs. A BDD framework involves creating executable specs known as “scenarios” that describe the application’s behavior.

The scenarios are in Given-When-Then format:

Through this format, all team members can be assured that the system behaves as expected and that all requirements are clearly understood.

How Does BDD Testing Work?

Behavior driven development (BDD) testing involves continuous collaboration between developers, testers, and business stakeholders. The goal is to write test scenarios that represent real-world behavior. 

These tests validate the system’s accuracy and provide living documentation on how the system should function. The process of BDD testing can be broken down into several stages:

Discovery Stage: In this initial phase, teams engage in workshops to discuss user stories and reach a consensus on desired behaviors. As they brainstorm, they illustrate how the system should behave under different scenarios.

Formulation Stage: Once behaviors are understood, teams use Gherkin to create executable specifications. This involves writing feature files that outline scenarios and their corresponding steps, making sure they are clear to everyone.

Automation Stage: In this final phase, the defined scenarios are automated using testing frameworks like Cucumber or SpecFlow. Each step in the Gherkin scenarios is mapped to code, allowing for efficient test execution during Continuous Integration (CI) processes.

Advantages of Behavior Driven Development Testing

Behavior Driven Development Testing offers several benefits that enhance the software development process and improve the quality of the final product. 

Here are some key advantages:

Improved Collaboration

BDD testing uses a common language to describe requirements, encouraging collaboration among developers, testers, and business stakeholders. As a result, business goals and objectives are aligned across the organization.

Early Detection of Issues

BDD testing promotes writing tests or acceptance criteria before the implementation begins. The test-first approach identifies potential issues early in the development cycle, reducing cost and effort later.

Living Documentation

The scenarios created in BDD testing serve as living documentation for the system. New team members or stakeholders can easily understand the system’s behavior by reading these descriptions.

Continuous Integration and Automation

BDD test scenarios can be automated and integrated into the continuous integration pipeline. As the software evolves, this reduces the risk of regressions and ensures its behavior is continually validated.

Focus on Business Value

BDD testing aligns development efforts with business goals by emphasizing the system’s behavior from the user’s perspective. This allows for the prioritization of user-value-added features.

Reduced Rework

When behavior is specified and reviewed upfront and continuously validated against the codebase, the risk of misunderstandings and rework is minimized. As a result, development cycles are more efficient, and software is of higher quality.

Challenges with Behavior Driven Development Testing

Despite its many advantages, BDD testing can present several challenges to teams. Understanding these challenges is important for BDD testing to succeed.

Formulaic Nature of Gherkin

Gherkin, used to write scenarios, has a structured syntax that can be restrictive. The structured approach may be challenging for teams used to writing user stories because it shifts focus away from the end user to specific features.

Integration with Agile Methodologies

BDD testing can struggle in environments that prioritize Agile practices. Agile involves fluid requirements, which can lead to frequent rewrites of features and tests. 

As a result of this flexibility, workloads and complexity can increase, potentially doubling the effort required.

Defining Comprehensive Scenarios 

BDD testing relies heavily on the quality of the scenarios defined. If critical test scenarios are missing, defects may go undetected. 

Therefore, product and development teams must collaborate closely to capture all relevant scenarios and ensure comprehensive requirements coverage. However, balancing scenario coverage with features and requirements an be challenging. Teams often focus heavily on scenarios, which may lead to gaps in understanding which features and requirements have been fully addressed or tested. Establishing a clear mapping process between scenarios, features, and requirements is crucial for maintaining alignment and preventing coverage gaps.

Perception as Sole Testing Method

BDD testing is often mistaken for being the sole testing methodology needed. While BDD testing excels at testing features and behaviors, it does not address other critical aspects such as usability, performance, or UI defects. 

Teams must still implement additional testing strategies to cover these areas comprehensively.

Initial Learning Curve

A cultural shift is required within teams to implement BDD testing. Developers and testers will need time, sometimes over 3+ months, to learn how to write Gherkin scenarios and understand BDD’s collaborative nature.

Tooling and Framework Limitations

Various tools are available for BDD testing, but they may be difficult to integrate with existing systems.

The right tools are crucial to the team’s workflow, but selecting them can be challenging.

Maintaining Scenario Relevance

Scenarios must be updated as projects evolve to meet changing requirements. When scenarios do not accurately reflect current business needs, they may lead to false confidence in a software’s functionality.

BDD Testing Process

The BDD testing process is structured and iterative, starting from requirement gathering and continuing through to continuous improvement. Below, we outline the key steps involved in the BDD Testing process.

1. Collaboration and Requirement Assemblage

The BDD testing process begins with developers, testers, and business stakeholders collaborating to gather and understand requirements. This allows everyone to understand why and what needs to be built.

The goal is to make sure all parties understand the requirements.

2. Writing User Stories

Once the requirements are gathered, they are translated into user stories. A user story is a simple description of a feature from the perspective of the end user. 

It typically follows the format: “As a [type of user], I want [an action] so that [a benefit].” This helps focus on the user’s needs and the value the feature will provide.

3. Defining Scenarios

User stories are then broken down into specific scenarios that describe the system’s expected behavior. These scenarios are written in Gherkin syntax, using the Given-When-Then format:

• Given: The initial context or state of the system.
• When: The action or event that triggers the behavior.
• Then: The expected outcome or result. This structured format helps in creating clear and concise scenarios that can be easily understood and automated.

4. Creating Automated Tests

The scenarios written in Gherkin are then converted into automated tests using BDD testing frameworks like Cucumber, SpecFlow, or Behave/JBehave. 

These tools parse Gherkin syntax and map it to test code, which interacts with the application. During this step, the scenarios must be executable so that they can be run during testing.

5. Running Tests

The automated tests are run frequently, often as part of the continuous integration pipeline. This ensures the system’s behavior is continuously validated against the defined scenarios. 

As the software develops, regularly running tests can help identify issues early and maintain reliability.

6. Feedback and Iteration

Based on the results of the tests, feedback is gathered and used to refine the scenarios, test code and the implementation. This iterative process helps keep the software up-to-date and meets user needs.

7. Continuous Improvement

BDD testing is an ongoing process that encourages continuous improvement. As new requirements arise or existing ones change, the scenarios are updated and refined. 

This ensures that the software remains aligned with the business goals and continues to deliver value to the users.

Tools and Frameworks for BDD Testing

In BDD testing, various tools and frameworks simplify the creation, execution, and management of test scenarios. Below are some of the most popular BDD tools available:

Cucumber

One of the most popular BDD testing frameworks is Cucumber. It supports multiple programming languages, such as Java, Ruby, JavaScript, Python, and more. Users can write test scenarios in the Gherkin language in a simple and readable way for humans.

To execute these scenarios, Cucumber can be easily integrated with a variety of test runners and automation tools.

Features:

• Gherkin Syntax Support
• Comprehensive Ecosystem with Plugins and Integrations
• Multi-Language and Platform Support

Behave

Behave is a BDD testing framework tailored for Python applications. It uses the Gherkin language to define behavior specifications in a natural, readable format. Behave integrates with Python’s testing ecosystem, making it suitable for both web and non-web applications.

Features:

• Gherkin Syntax Support
• Integration with Python Testing Libraries
• User-Friendly Command-Line Tools

JBehave

JBehave is a BDD testing framework designed specifically for Java applications. It enables developers to write scenarios in natural language and provides a unique methodology for defining stories and steps, which are then mapped to Java code for execution.

Features:

• Natural Language Scenarios
• Integration with Testing Frameworks
• Flexible Story and Step Management

SpecFlow

SpecFlow is a widely-used BDD testing framework for .NET applications, enabling users to write test scenarios in Gherkin language. It binds these scenarios to C# code and integrates seamlessly with various .NET test runners and CI/CD pipelines.

Features:

• Gherkin Syntax Support
• Integration with Test Runners
• Rich Development Environment Integration

Concordion

Concordion is a BDD testing framework for Java that merges executable specifications with documentation. It allows users to write tests that double as specifications and documentation, enhancing understanding among stakeholders.

Features:

• Dual-Purpose Tests
• Java Testing Framework Integration
• Enhanced Collaboration

FitNesse

FitNesse is a web-based BDD testing framework that enables teams to create executable specifications in a wiki-like environment. It supports various programming languages and testing frameworks, making it highly versatile for projects.

Features:

• Collaborative Platform
• Multi-Language Support
• Easy Test Management

How to Write an Effective BDD Test

Writing effective Behavior Driven Development (BDD) tests involves a structured approach emphasizing collaboration, clarity, and continuous improvement. Here’s a step-by-step guide to creating impactful BDD tests.

Collaborate with Stakeholders

All relevant stakeholders, including product owners, developers, and testers, should be involved early in development. The goal of collaboration is to ensure that everyone understands the users’ needs and expectations. 

It helps build user stories and acceptance criteria that accurately reflect the desired behavior of the application based on collective input.

Define Clear User Stories

User stories should be concise and written from the end-user’s perspective. A well-defined user story typically follows the format:

• As a [role],
• I want [goal],
• So that [reason].

The structure sets the stage for subsequent scenarios by clarifying the feature’s purpose and value.

Create Scenarios Using the Given/When/Then Format

For each user story, outline specific scenarios using the Given/When/Then method. A behavior can be broken down into three components using this format:

• Given: The initial context or setup.
• When: The action taken by the user.
• Then: The expected outcome.

For example:

This clear structure helps in understanding and testing expected behaviors.

Ensure Coverage

Your tests should cover all critical scenarios, including edge cases and variations in user behavior. Comprehensive coverage reduces the risk of defects and ensures that all aspects of the feature are validated.

Prioritize Clarity and Conciseness

Write scenarios in simple, clear language for both technical and non-technical stakeholders.

Readers may become confused by jargon or overly complex terminology. It is important to keep descriptions concise so essential behaviors can be focused.

Automate the Tests

Once scenarios are defined, automate them using the right BDD testing tools. Automation allows for consistent test execution, making it easier to validate behavior as development progresses. 

Automated tests can be run frequently, providing immediate feedback on changes.

Run and Validate Tests

Execute your automated tests regularly to validate that the application behaves as expected. This continuous testing helps catch issues early in the development cycle, allowing for timely fixes and adjustments.

Iterate and Refine

Iteration is a critical component of BDD testing; it allows teams to adapt to evolving project requirements while maintaining the relevance and effectiveness of tests.

As development progresses, revisit your scenarios to refine them based on new insights or changing requirements. 

Document and Share

Document user stories, scenarios, and test results. Sharing this information benefits all stakeholders, fostering transparency and aligning everyone with the project’s objectives. Documentation also serves as a reference for future development efforts.

BDD in Agile and Continuous Delivery

BDD testing integrates easily with Agile and Continuous Delivery methodologies, enhancing collaboration, improving communication, and ensuring software meets user needs.

1. Enhanced Collaboration in Agile
   BDD testing promotes collaboration among developers, testers, and business stakeholders by using a common language to describe requirements. 

   As a result of this shared understanding, Agile teams are able to align on business goals and objectives, reducing misunderstandings and rework.

2. Improved Communication
   Clear and continuous communication is crucial in Agile environments. As scenarios are described using natural language, BDD testing makes it easier for non-technical people to participate in the development process. This ensures that the software meets the users’ actual needs.
3. Integration with Continuous Delivery
   BDD testing scenarios can be automated and integrated into the continuous integration and delivery pipeline. This ensures that the system’s behavior is continuously validated, reducing the risk of regressions and ensuring that the software remains reliable as it evolves.
4. Early Detection of Issues
   By writing tests before implementation, BDD testing helps identify potential issues early in the development cycle. This test-first approach aligns well with Agile practices, where early feedback and iterative improvements are key.
5. Living Documentation
   The scenarios created in BDD testing serve as living documentation for the system. They provide a clear and concise description of the system’s behavior, which can be easily understood by new team members or stakeholders. This is particularly valuable in Agile environments, where requirements and priorities change rapidly.
6. Focus on Business Value
   BDD testing ensures that development efforts are aligned with business goals by emphasizing the system’s behavior from the user’s perspective. This helps prioritize features that deliver the most value to the users, a core principle of Agile methodologies.
7. Continuous Improvement
   Continuous improvement is a fundamental principle in both Agile and Continuous Delivery. BDD supports this by encouraging regular updates and refinements to scenarios based on feedback from automated tests and user interactions.

Why You Should Perform BDD Tests on Real Devices

Running Behavior Driven Development (BDD) tests on real devices is crucial for achieving accurate and reliable results. Here are the key reasons why testing on real devices is essential:

1. Realistic Testing Conditions
   A real device simulates how users will interact with your application under actual circumstances, such as with different hardware specifications, operating systems, and network options. It helps identify issues that may not be evident in emulators or simulators, like device-specific bugs or location-specific bugs due network connectivity conditions.
2. Improved Security
   Test environments in a real device cloud are secure, isolated, and meet high security standards. This minimizes data breaches and protects sensitive information during testing.
3. Broad Browser and OS Coverage
   Team members can test compatibility issues between browsers and operating systems on real devices. The broad platform coverage allows the application to run correctly on all platforms, improving the user experience.
4. Performance Insights
   Real devices give you authentic performance data, which is essential to optimizing apps. The data helps developers figure out how the app behaves in real-world scenarios, so they can tune it better.
5. Scalability and Accessibility
   Distributed teams can scale and access testing using a real device cloud. Tests can be run simultaneously across multiple devices, improving efficiency and collaboration.
6. CI/CD Integration
   The real device testing process integrates smoothly with Continuous Integration/Continuous Deployment (CI/CD) pipelines, allowing continuous testing and early issue detection. Throughout the development lifecycle, this integration helps maintain high standards.
7. Cost-Effectiveness
   While testing on real devices may seem initially costly, it saves long-term costs associated with fixing bugs and solving support issues resulting from inadequate testing environments. The earlier a problem is detected, the lower the risk of significant rework later in the development cycle.

Final Thoughts

Behavior Driven Development Testing is a powerful approach that facilitates collaboration, clarity, and quality in software development. By focusing on user behaviors and using a shared language, BDD aligns all stakeholders with business goals, streamlining the development process and identifying defects early.

Testlio offers a robust platform for effective BDD testing. It easily integrates automated BDD tests into your CI/CD pipeline for continuous feedback and rapid iterations. Additionally, you get access to a network of experienced testers who understand BDD practices, helping streamline your testing practices.

Get started with Testlio today to upgrade your BDD testing capabilities!