Designing and Testing with Behaviours rather than requirements

A few months ago I decided that I wanted to learn something new. I decided that I would have a go on the Google App Engine, learning Python and jQuery. I decided that I would start working on something that would be useful, at least for me, and go from there. I also thought that I would give Behaviour Driven Development a try

I decided that I would work on a project management application. So the first thing I needed was a way to store my backlog and visually see where items were on the stack.

Since I have a stack on bits of paper and want to do this by describing my behaviors for each of my requirements I need a way to describe them that I can easily translate into a test. I went looking through all the different BDD Frameworks (NBehave, Behaviour, JBehave, RBehave,StoryQ, and many many more!) to look for the common phrases and it came back with the phrase that I think is brilliant. It flows off the tongue so easily that getting product owners involved to write them can make an agile project work like clockwork.

The phrase is below. NOTE: The bold items make the main phrase up and the italics make it more readable.

As a product owner
I want functionality
so that something is done
with Scenarios

Scenario 1:
Given start point
When do something
Then expections will be met
.
.
.
Scenario n:
.
.
.

This can easily be coded into different languages and in some of the languages the natural language above is all that is needed but just a little tweaking to get the functions calls sorted. If you are a Selenium nut like me you could even drive with something like FitNesse. Gojko Adzic has explained it really well on his blog so suggest you have a look there.

The other plus point for BDD in Agile environments is its ability to change the BDD test very quickly if the product owner changes their mind. And since product owners change their minds every time they have a cup of tea, and in the UK it can be very often, you need to be able to keep your tests up to date.