BDD testing is an extension of Test-driven development (TDD). Like in TDD, BDD tests are written before writing and adding application code. The major difference that we get to see here are:

•  Tests are written in plain descriptive English type grammar
•  Tests are explained as behaviour of application and are more user focused
•  Using examples to clarify requirements.

Advantages of BDD

• 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 behaviour scenarios because they are written in plain language
• Clarity: Scenarios focus on the expected behaviours of the product.
• Automation: BDD frameworks make it easy to turn scenarios into automated test
• Test-Driven: BDD is an evolution of TDD
• Adaptability: BDD scenarios are easy to update as the product changes. Plain language is easy to edit. Modular design makes changes to automation code safe

There are various tools which support BDD like Cucumber, JBehave, SpecFlow etc. Here we are going to focus on Cucumber.

Cucumber is a free open source BDD tool originally written in Ruby programming language that runs automated tests. It keeps specifications, automated test scripts, and documentation in the same place. For a complex project, a team first writes the examples and then runs them in Cucumber. 

Cucumber further tells you which ones are working, and which ones aren’t. It lets you define application behaviour in plain descriptive/meaningful English text using a simple grammar defined by a language called Gherkin. It can be used to “test” the code written in other languages like Java, Ruby etc.

Main Features

• Writing BDD tests in an omnipresent language, a language structured around the domain model and widely used by all team members comprising of developers, testers, BAs, and customers 
• Connecting technical with nontechnical members of a software team
• It allows direct interaction with the developer’s code, but BDD tests are written in a language which can also be made out by business stakeholders
• Finally, acceptance tests can be executed automatically, while it is performed manually by business stakeholders.

Keywords used in Cucumber tests:

An example of a Cucumber test is: