What can BDD do for you? Why adopt a new process with a new framework? Because it’s worth it! This article gives a dozen awesome benefits of BDD. (If you read the BDD 101 series, then these points should look familiar.)
BDD is meant to be collaborative. Everyone from the customer to the tester should be able to easily engage in product development. And anyone can write behavior scenarios because they are written in plain language. Scenarios are:
- Requirements for product owners
- Acceptance criteria for developers
- Test cases for testers
- Scripts for automators
- Description for other stakeholders
Essentially, BDD is an enhancement of The Three Amigos.
Scenarios focus on the expected behaviors of the product. Each scenario focuses on one specific thing. Behaviors are described in plain language, and any ambiguity can be clarified with a simple conversation. There’s no unreadable code or obscure technical jargon, and there’s no game of telephone. Clarity ensures the customer gets what the customer wants.
BDD is designed to speed up the development process. Everyone involved in development relies upon the same scenarios. Scenarios are requirements, acceptance criteria, test cases, and test scripts all in one – there is no need to write any other artifact. Furthermore, the modular nature of Gherkin syntax expedites test automation development.
#4: Shift Left
“Shift left” is a buzzword for testing early in the development process. Testing earlier means fewer bugs later. In BDD, test case definition inherently becomes part of the requirements phase (for waterfall) or grooming (for Agile). As soon as behavior scenarios are written, testing and automation can theoretically begin.
Scenarios form a collection of self-documenting test cases as a result of the BDD process. This ever-growing collection forms a perfect regression test suite. Scenarios can be run manually or with automation. Any tests not automated can be added to a backlog to automate in the future.
BDD frameworks make it easy to turn scenarios into automated tests. The steps are already given by the scenarios – the automation engineer simply needs to write a method/function to perform each step’s operations.
BDD is an evolution of TDD. Writing scenarios from the beginning enforces quality-first and test-first mindsets. BDD automation can run scenarios to fail until the feature is implemented and causes tests to pass.
#8: Code Reuse
Given-When-Then steps can be reused between scenarios. The underlying implementation for each step does not change. Automation code becomes very modular.
Scenario steps can be parameterized to be even more reusable. For example, a step to click a button can take in its ID. Parameterization can help a team adopt a common, reusable set of steps, and it inspires healthier discussion when writing scenarios.
Scenario outlines make it easy to run the same scenario with different combinations of inputs. This is a simple but powerful way to expand test coverage without code duplication, which is the bane of test automation.
BDD has a snowball effect: scenarios become easier and faster to write and automate as more step definitions are added. Scenarios typically share common steps. Sometimes, new scenarios need nothing more than different step parameters or just one new line.
BDD scenarios are easy to update as the product changes. Plain language is easy to edit. Modular design makes changes to automation code safer. Scenarios can also be filtered by tag name to decide what runs and what doesn’t.