Java Unit Testing Patterns: Behavior-Driven Development

Omed Habib

September 7, 2023

Behavior-driven development (BDD) represents a transformative approach in the world of software development, merging the precision of test-driven development (TDD) with the articulacy of natural language. This method bridges the gap between technical and non-technical stakeholders, fostering a shared vision and understanding of a project. BDD stands out for its emphasis on collaboration and clarity, utilizing a unique "Given-When-Then" format to articulate test scenarios. This blog explores the intricacies of BDD, its role in enhancing team communication, and its practical implementation in Java, showcasing how this approach leads to more expressive, robust, and user-centric software solutions.

Behavior-driven development (BDD) in software is akin to a choreographer staging a dance performance. Just as a choreographer outlines each movement, scene, and expression in dance, BDD articulates software behavior in clear, precise steps using the "Given-When-Then" structure. The choreographer's script, much like BDD's scenarios, is easily understood by dancers and non-dancers (developers and non-technical stakeholders) alike, ensuring everyone shares a cohesive vision of the final performance (software product). Each step of the choreography (test case) is rehearsed (tested) to perfection, ensuring that the entire ensemble (development team) is in harmony and the final performance (software) is a seamless, expressive masterpiece that resonates with its audience (users).

Behavior-Driven Development (BDD)

Behavior-Driven Development (BDD) is a software development process that combines elements of test-driven development (TDD) with a focus on writing test cases that are expressed in a natural language. This makes them more readable and understandable for both developers and non-technical stakeholders.BDD uses a "Given-When-Then" structure to describe test scenarios, which enhances the clarity and expressiveness of the tests. This structure also encourages collaboration between developers, testers, and business analysts, as it promotes a shared understanding of the system's behavior.

A typical BDD test case starts with the "Given" section, which sets the initial conditions for the test. This is followed by the "When" section, which describes the action that is being performed. Finally, the "Then" section specifies the expected outcome of the action.

BDD frameworks, such as JBehave and Cucumber, provide tools and support for writing and executing BDD-style tests in Java. These frameworks generate documentation that outlines the test scenarios in a user-friendly format, making it easier for stakeholders to understand the system's behavior and validate the test results.

By adopting BDD, Java developers can create tests that are more expressive, readable, and maintainable. This approach also enhances communication and collaboration within the development team and improves the overall quality of the software product.


Let's say we want to test a basic functionality in a banking application where a user can check their account balance. We will use the BDD approach to define this behavior.

Step 1: Writing Feature File

First, we write a feature file in Cucumber, which describes our test scenario in natural language using the "Given-When-Then" format.

Step 2: Defining Step Definitions

Next, we create step definitions in Java that match the steps in our feature file. These steps contain the actual test code.

Step 3: Running the Test

With Cucumber set up, running the test involves executing the feature file. Cucumber matches the steps in the feature file with the Java step definitions and runs the test. If the conditions are met as described in the "Then" step, the test passes.

Note: This is a simplified example. In a real-world application, the step definitions would interact with the application's code to perform actions (like checking the balance) and validate the outcomes.

This BDD example demonstrates how the process starts with a human-readable description of the desired behavior and then links that description to the actual test code, ensuring both clarity and technical accuracy.

In conclusion, Behavior-Driven Development is more than just a methodology; it's a communication and collaboration catalyst in the software development process. By adopting BDD, Java developers, and teams not only construct clearer and more maintainable tests but also build a common language that bridges the divide between technical and non-technical team members. This shared understanding is crucial for aligning software products with business goals and user needs. BDD, therefore, doesn't just improve the quality of code; it enhances the quality of interactions within development teams and, ultimately, the quality of the software solutions delivered to users. Like a well-rehearsed dance, BDD ensures every movement in the development process is purposefully coordinated and contributes to a harmonious and impactful final product.