What is meant by Behavior Driven Development (BDD)?

BDD or Behavior Driven Development is one of the most important development approaches in the field of software engineering and is just a modified implementation of the TDD or test driven development. It actually combines the guiding principles and general techniques of the test driven development with the combined ideas from two sources namely:

1. Domain – driven design
2. Object – oriented analysis and design

- The behavior driven development thus provides a shared process and tools to business analysts and software developers for their collaboration on the software development process.

- Ideally, behavior driven development represents an idea regarding the management of the software development process by both technical sight and business interests.

- It is assumed in this approach that the specialized software tools are being used to provide support to the development process. 

- The specialized tools thus involved have been developed especially to be used in projects following the BDD approach. 

- They can be considered as special tools that supports test driven development. 

- The primary purpose of these tools is to automate the ubiquitous language statements around which the BDD process is centralized. 

- Agile software development gets successful only when it is considered from the beginning. 

- On the contrast, in some projects this is the last thing to be considered which means that there is no sustainable operation in the websites that serve purposes other than blogging.

-  A blogging web site is just a software that is just modified by the users as it is ready for use. 

- However, BDD and TDD provides the only ways for achieving this goal. 

- The word ‘driven’ in TDD signifies that the test cases are written first and then the code for passing the test. 

- TDD is actually a low level methodology of accomplishing tasks and is sort of developer oriented. 

- On the other hand in BDD, the description of the tests is written in a natural language, thus making the tests more accessible to people outside the development team. 

- Such descriptions can describe the functionality in the same way as done by the specifications. 

Dan North was the person who actually brought the concept of behavior driven development in response to the issues experienced in implementing the test driven development such as:

1. From where to start testing?
2. What is to be tested?
3. How much should be tested in one turn?
4. How the reason for the failure of the test is to be understood?

- At the heart of the behavior driven development approach lies the approach to acceptance testing and unit testing which were again identified by North. 

- He emphasized that the acceptance tests should be written using the user story frame work. 

- Thus starting from the scratch, the development of the BDD approach continued over a couple of years and finally we have it as a communication and collaboration framework. 

- It has been designed especially for the QA people and business participants involved in a project.

- The agile specifications, BDD and testing eXchange meet highlighted the following characteristics of BDD:

1. Second generation methodology
2. Outside – in approach
3. Pull based
4. Multiple stake holder support
5. Multiple scale generation
6. High automation process
7. Agile methodology

- Further, it was said that it involves a cycle of interactions with outputs that are well defined and results in delivery of working software that makes sense. - First, BDD frame work that came in to existence was Jbehave which was followed by Rbehave–a story level BDD ruby frame work.

- All these frameworks were later replaced by cucumber testing tool. It was developed by Aslak Hellesoy.