Behavior-based development streamlines software development

In this competitive digital age, the importance of software testing is well recognized and acknowledged. However, what to test, when to test, and how to test has continually evolved over time as we move down the progressive path of software development. Organizations today need to deliver high-quality software faster than ever. As agilists, we also strive to achieve business agility by reducing volatility, uncertainty, complexity and ambiguity. This task can be overwhelming in a world that demands the continuous delivery of quality products.

The use of automated testing techniques is an engineering practice that we can use to help us continually improve this quality quickly and efficiently; but how do we ensure that we write effective test cases in the first place – test cases that validate that our applications meet business expectations?

Believe it or not, it all starts with collaboration. Behavior-driven development, or BDD, is an agile software development process that encourages collaboration in a software project between the IT team – requirements analysts, developers, QA, project managers – and the business team. The main objective of the BDD methodology is to improve communication between project stakeholders so that each feature and associated user story is properly understood by all team members before the development process begins. This ensures that the entire team is focused on quality, helps identify key scenarios or test cases for each story, and most importantly, helps eliminate ambiguities in requirements.

The key to success is to shift the creation of tests to the left or to 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 met.

Developers implement the system using tests – writing just enough code to pass the test cases. By continuously testing for the existence of a given feature and writing code to introduce a feature that can pass the tests, the effort of the developers is optimized to the point of meeting the requirement. Additionally, tests and requirements become interdependent, always ensuring proper test coverage and eliminating or minimizing unexpected results.

Tests are specified in terms of activity domain in the form of plain English scenarios using the Gherkin syntax – Given, When, Then – created specifically for behavior descriptions. The terms of the business domain then form an omnipresent language shared between the business and technical teams. This means that no development skills are required to create tests. This promotes effective communication between technical and non-technical stakeholders, which raises early questions about the accuracy of test cases and provides an opportunity to resolve differences in perspective.

Now, while adopting a software development process like BDD doesn’t require adopting automation, one of the biggest benefits it offers is streamlining test automation with tools such as Cucumber.

Cucumber, an open source software tool, is a test framework that supports BDD and is driven by plain English scenarios using Gherkin syntax. Cucumber reads the code in plain text and associates each step with an associated “step definition”, a block of code that executes the Given-When-Then specifications against the system under test.

Cucumber allows us to use various testing tools such as Selenium, Appium, web services clients, database drivers and many others, promoting full automation on the various interfaces that make up our software products. When we build automation into BDD, we create a complete process that delivers tremendous benefits and value: we collaborate, record that collaboration in a specification form, and then automate that specification to drive implementation.

Implementing an industry best practice like behavior-driven development (BDD) while integrating automation has been proven to provide the following benefits:

  • Inclusion. BDD wants to be collaborative. Everyone, from the customer to the tester, must be able to easily engage in the development of the product. And anyone can write behavior scripts because they’re 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 focuses on one specific thing. Behaviors are described in plain language and any ambiguity can be clarified with a simple conversation or mapping example. There’s no unreadable code or arcane technical jargon, and there’s no phone game. Clarity ensures that business expectations are always met.
  • Rationalization. BDD is designed to speed up the development process. Everyone involved in development relies on the same scenarios. Scenarios are requirements, acceptance criteria, test cases and test scripts all in one – there is no need to write another artifact. The modular nature of the Gherkin syntax accelerates the development of test automation. Additionally, scenarios can be used as steps to reproduce failures for defect reporting.
  • Left offset. “Shift left” is a buzzword for testing early in the development process. Testing earlier means fewer bugs later. In BDD, test case definition is an intrinsic part of requirements preparation. Testing and automation can theoretically begin as soon as behavior scenarios are written.
  • Focused on quality. BDD is an evolution of test-driven development or TDD. Writing scripts early on reinforces quality and test-first mentalities.
  • Reusability. Given-When-Then steps can be reused between scenarios. The underlying implementation of each step does not change. The automation code becomes very modular.
  • Momentum. BDD has a snowball effect: scenarios become easier and faster to write and automate as new step definitions are added. Scenarios generally share common steps. Sometimes new scenarios just need different step parameters or just one new line.
  • Adaptability. BDD scenarios are easy to update as the product changes. Simple language is easy to edit. The modular design makes changes to automation code safer. Scenarios can also be filtered by tag name to decide what works and what doesn’t.
  • Cost savings. BDD also makes the software development process more effective and efficient overall, resulting in significant cost savings. BDD supports shortened test cycles, decreased defects, increased test coverage and frequency, reduced labor costs, and improved delivery predictability, consistency, and continuity.

After the full BDD process, we end up quickly and efficiently creating software applications that are not only well-built and tested, but also aligned with business needs and expectations. With BDD, software development teams can ensure they consistently deliver high-quality software that matters.

Comments are closed.