What is Behavior Driven Development (BDD)?
What you need to know about Behavior Driven Development
Behavior Driven Development (BDD) is an Agile Software Development process that enhances collaboration among developers, QA, and or business participants in a software project.
BDD uses examples to illustrate the behavior of the system that is written in a readable and understandable language for everyone involved in the development.
At its core, Behavior Driven Development is a software development methodology that joins best practices gotten from development (TDD) and design (DDD) to simplify development through the use of a common language (DSL) to understand natural language sentences and convert them into executable tests, an example is the testing framework on ruby on rails.
BDD Use Cases
BDD is a way for software teams to close the gap between business people and technology. BDD has so many use cases and the following is a list:
- Encouraging collaboration across roles to build a shared understanding of the problem to be solved.
- Working in rapid, small iterations to increase feedback and the flow of value.
- Producing system documentation that is automatically checked against the system’s behavior.
- Deals with below conducting behavior-specific tests or functional specifications that outline executable scenarios for the application.
- Identifying a single outcome for every behavior.
- Translating each scenario into the domain-specific language (DSL) to ensure accurate communication.
- Gathering all behaviors into one set of documentation so it is accessible for all developers, testers, and stakeholders.
Principles of Behavior-Driven Development
- Behavioral Specifications: Defining behaviors within BDD is achieved through user stories. User stories are written-out scenarios that hold some sort of baseline title that summarizes the intent, a narrative section that describes the who and what that should be involved in achieving this story requirement, and the scenarios section that describes a series of specific scenarios via if-then-style conditions.
- Ubiquitous Language: BDD heavily indicates the influence of a ubiquitous language, which known as domain-specific language or DSL. DSL should be clearly defined and agreed upon early by all team members in the development life cycle. DSL paves way for easy communication about the domain of the project and should be both simple and robust enough to support discussion between all types of personnel, from developers and team leaders to customers and business executives.
- Using Specialized Tools: Behavior-driven development is massively supported by specialized tools that help in the creation and execution of testing suites. Just like automated testing tools used in test-driven development, BDD tools will similarly perform automated tests in an aim to streamline the development process.
Benefits of Behaviour Driven Development
The benefits of developments are countless, some of which are:
- The user needs are achieved through software development.
- BDD improves code quality thereby reducing the cost of maintaining the project.
- BDD makes sure that the software is designed based on the client’s business principle.
- Teams using BDD are more confident in their code.
- High visibility.
- Strong collaboration.
- It’s a ubiquitous language.
- BDD focus on user needs.
- Better communication between developers, testers, and product owners.
- Because BDD is explained using simple language, the learning curve will be much shorter.
- Being non-technical in nature, it can reach a wider audience.
- The behavioral approach defines acceptance criteria prior to development.
- You are no longer defining ‘test’, but are defining ‘behavior’.
- BDD lets us develop, test, and think about the code from the view of the business owner.
Features of Behaviour Driven Development:
Below are some of the features of a few Behaviour Driven Development tools:
CUCUMBER
Cucumber is a test framework that supports BDD, and some of its features are:
- Integration with all the most popular testing libraries.
- Specifying the behavior looking at the system from the outside.
- Defining executable specifications in different ways like lists, prose, and tabular data.
- The plain text files can be stored in any version control system.
- Collaboration and coming up with a good and clear set of Acceptance Criteria.
JBEHAVE
JBehave is a similar alternative to Cucumber, and some of its features are:
- Pure Java implementation, which plays well with or when interfacing any environment that exposes a Java API.
- Users can choose and run text-based user stories, “out-in” development.
- User stories can be written in JBehave syntax Gherkin syntax.
- User stories can be documented via generic user-defined meta information that allows easy story filtering and into story maps.
- Dependency Injection support allowing both configuration and Steps instances composed via your container (Guice, Needle, PicoContainer, Spring, Weld).
- Localization of user stories, allowing them to be written in any language.
- Groovy scripting supported for writing configuration and Steps instances
- Pluggable step strategy. Strategies bundled in include: by priority field and by Levenshtein Distance.
- Auto-generation of pending steps so the build is not broken missing step, but has to configure breaking build.
- IDE integration: stories can be run as JUnit tests or unit test frameworks, providing easy integration IDE.
- Ant integration: allows stories to be run via an Ant task
- Annotation-based binding of textual steps to Java methods, with auto-conversion of string arguments to any parameter type (including generic types) via custom parameter converters.
- Story report format in JSON and XML, consumable by external applications.