As the term signifies, behavior of the developed software brings about the behavior-driven development (BDD) approach. This methodology is based on customers' expectations and perspectives. Daniel North, a pioneer of this concept, published an article on BDD in 2006 that soon gained popularity, and since then, the BDD approach has been widely adopted by a lot of software development companies.
BDD describes the set of behaviors that the user can expect from the software, and this methodology is generally applied by product managers and business analysts. Since it is written in plain English, even those without any technical knowledge can understand the expected software behavior. It bridges the gap between a business team and a technical team.
This article explains the basics of behavior-driven development, and provides you with the examples, scenarios, and the list of popular BDD tools.
BDD tools are not testing tools – they help you get a common understanding of how the software should behave. It’s mainly applied in the use case scenarios where a business team has a strong reason to assess the system behavior. It can be synced with integration tests, end-to-end tests, etc. You can integrate the BDD approach into the various scenarios, including the one when you build a web app or a mobile app using a low-code development platform.
Here is a simple behavioral scenario for an ATM written in plain English, using Gherkin syntax, and having the Given-When-Then structure:
Given the account balance is 100 Dollars
And the ATM contains the cash
When the Account holder requests 20 Dollars
Then the ATM should dispense 20 Dollars
And the account balance should reflect 80 Dollars
In the Cucumber tool, you write these tests in Gherkin so that even non-tech-savvy individuals could understand them. When your developers get the tests, they can import the test scenarios into their development tool, and then automate the scenario steps accordingly. Once you stabilize the flow, they can regularly include these scenarios into the automated tests.
The scenario includes 3 sections – Context, Events, Outcome.
If a behavior functions appropriately according to the BDD scenario, the feature is marked as working. Every feature is associated with a feature file, and the set of behaviors is termed as a contract.
Behavior-driven development encourages the collaboration between business analysts, developers, and QA engineers. Due to the constant cooperation, they share the overall understanding of the business requirements taking into account the customer’s perspective as well.
We can also define behavior-driven development as a set of practices that helps you enable your teams to deliver software iteratively and incrementally. This set of practices includes Discovery, Formulation, Automation. They can be integrated with any of the agile methodologies like Scrum, Safe, etc.
Several development and automation test tools can be integrated with behavior-driven development tools. As a rule, developers and testers formulate BDD scenarios based on a discovery phase and the results of the collaboration with business analysts, an Ops team, etc.
Test automation developers conduct test automation before the implementation of the code in production. Generally, the steps are the following:
For example, you have a feature with the context: “Given the car has started”. Then, when generating the step definition, you’d see the associated code as per the programming language in the development tool:
Given ("The car has started", function ())
// Code here
The function is run when the scenario is triggered.
Most popular BDD tools can be easily integrated with the development tools any dev team uses. Eclipse IDE, TestProject, etc., allow integration with the following BDD tools.
It can be tough to implement behavior-driven development without enough collaboration between business analysts, developers, QA engineers, an Ops team, etc. This way of working aligns perfectly with a DevOps, or a DevSecOps approach. Thus, all the team members are encouraged to be constantly in sync. When opting for a siloed working approach, you’ll hardly succeed in BDD.
If you choose to adhere to the behavior-driven development methodology, make sure that your team starts collaborating from the discovery phase. The three amigos – BA, Dev, and QA teams – interact with each other while gathering the requirements and defining the specifications. Constant communication and quick feedback are vital in the BDD process.
When following the behavior-driven development methodology, you combine both business and technical aspects. BDD is not a simple testing activity – it’s a technique for designing & developing your software. It has also proven to enhance test automation in many ways.