BDD (or Behavior-Driven Development) is a software development methodology that emphasises collaboration among developers, quality assurance (QA) and non-technical colleagues such as product designers and business developers.
BDD testing focuses on testing the behavior of a software application from the perspective of a user. This type of testing typically involves the creation and execution of scenarios written in a natural language, that describes the expected behavior of the application or website that is being tested.
Because it is easy to read, people unfamiliar with testing can easily understand what the test does and what the expected outcome is.
Some of the advantages of adopting BDD testing are:
-
Tests are written in the Gherkin language
BDD scenarios are often written using a domain-specific language called Gherkin. Gherkin uses a syntax that is easy to understand by both technical and non-technical team members. It includes keywords such as
Feature
,Scenario
,Given
,When
andThen
to describe what is going to be tested and what the expected outcome is. -
Living Documentation
BDD scenarios act as living documentation for the software and its tests. These scenarios provide an up-to-date and executable description of what the system's (expected) behavior is. As the documentation evolves with the codebase, it is guaranteed that the test scenarios remain relevant and correct.
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Test-Driven Development (TDD)
BDD complements Test-Driven Development (TDD) by providing a higher-level perspective on system behavior. BDD scenarios can be written before development begins and serve as a guide for developers to implement features.
Popular BDD frameworks include Cucumber (specifically with Gherkin syntax), Behave for Python, SpecFlow for .NET, and JBehave for Java. These frameworks provide integrations with Selenium and Appium, allowing you to write and run BDD tests against websites and mobile apps.