In this competitive digital era, the importance of software testing is well recognized and acknowledged. However, what to test, when to test, and how to test is not as simple as it sounds. Development teams must deliver high-quality software faster than ever before while maintaining business agility, that is, by reducing volatility, uncertainty, complexity and ambiguity. This task can be overwhelming in a world that demands continuous delivery of quality products. Automated testing can help testers drive quality with speed and efficiency, but how do we ensure we are writing effective test cases in the first place – test cases that validate that our applications are satisfying business expectations?
It all starts with collaboration. Behavior-Driven Development, or BDD, is an agile software development process that encourages collaboration in a project between the IT team—requirements analysts, developers, QA, project managers—and the business team. The primary purpose of BDD methodology is to improve communication between project stakeholders so that everyone on the team understands each feature and related user story before development starts. This ensures the entire team is focused on quality, helps to identify key scenarios or test cases for each story, and helps eradicate ambiguities from requirements.
The key to delivering quality software faster is to shift test creation to the left or at the beginning of a project, rather than creating tests after development is complete. BDD aims to help a project team flesh out user stories into detailed test scenarios that, when executed, will confirm whether the intended functionality exists and the associated business requirements are satisfied. Developers implement the system using the tests, writing just enough code to pass the test scenarios.
Write the Right Amount of Code
Continuously testing for the existence of a given functionality and writing code to introduce functionality that can pass the tests optimize developers’ efforts to the point of just meeting the requirement. Tests and requirements become interrelated, ensuring proper test coverage and eliminating or minimizing unexpected results.
The tests are specified in business domain terms in the form of plain English scenarios using the Gherkin syntax (Given, When, Then) created specifically for behavior descriptions. The business domain terms then form a ubiquitous language shared between the business team and the technical team. No development skills are required for creating tests as tests are written in the ubiquitous language. This promotes effective communication between technical and non-technical stakeholders, prompting early questions around whether the test scenarios are accurate. It also provides an opportunity to resolve differences in points of view.
While BDD does not require automation adoption, one of the greatest benefits it provides is the streamlining of test automation with tools such as the open-source testing tool Cucumber. This testing framework supports BDD and is driven by plain-English scenarios using the Gherkin syntax. Cucumber reads the code written in plain-English text and matches each step with an associated “step definition” or a code block that executes the Given, When, and Then specifications against the system under test. Cucumber allows testers to use tools like Selenium, Appium, web service clients, database drivers, and many more, promoting full-scope automation across the various interfaces that make up our software products.
When we incorporate automation with BDD we create a full-stack process that provides tremendous benefit and value: we collaborate, we record that collaboration in a specification, and then we automate that specification to drive the implementation.
Eight Reasons to Use BDD Now
Implementing Behavior-Driven Development (BDD) while incorporating automation brings many benefits:
- Inclusion. 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 automation, and descriptions for other stakeholders.
- Clarity. Scenarios focus on the expected behaviors of the product. Each scenario emphases one specific thing. Behaviors are described in plain language, and any ambiguity can be clarified with a simple conversation or example mapping. There’s no unreadable code or obscure technical jargon, and there’s no game of telephone. Clarity ensures that business expectations are always satisfied.
- Streamlining. 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. The modular nature of Gherkin syntax expedites test-automation development. Scenarios can be used as steps to reproduce failures for defect reports.
- 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 requirements grooming. As soon as behavior scenarios are written, testing and automation can theoretically begin.
- Quality-Driven. BDD is an evolution of TDD (Test-Driven Development). Writing scenarios from the beginning enforces quality-first and test-first mind-sets.
- Reusability. Given-When-Then steps can be reused between scenarios. The underlying implementation for each step does not change. Automation code becomes very modular.
- Momentum. 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.
- Adaptability. 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.
Following the full-stack BDD process, developers end up creating software applications quickly and effectively that are not only well-built and tested, but also what the business needs and expects. With BDD, software development teams can continually deliver high-quality software that matters.