Simple BDD is a way to bring structured natural language BDD syntax into any test framework, but why is this necessary?
Have you ever looked back a test you wrote several months ago, or even the several hours ago and wondered what you were thinking and what you were trying to achieve? Behaviour Driven Development (BDD) attempts to resolve this with the structured language or ‘given’, ‘when’ and ‘then’ and natural language describing how an application should behave.
There are a growing number of tools to assist using BDD in Ruby and Rails today, notably Cucumber. Cucumber extracts the behaviour of the application into plain text files using natural language and uses a parser to translate these into methods which should be executed in relation to the natural language.
What if you’ve already got a good test suite, but you just want some of the structured language that something like Cucumber gives you? Well, recently I created a tiny Ruby library to do just this, Simple BDD. Simple BDD allows use of natural language within any executable code, be that RSpec or any flavour of test library.
Given "an authenticated user"
When "that user submits a message less than 140 characters"
Then "that message is displayed to the users followers"
And "is also shown in the users timeline"
These natural language statements are translated into method calls which are executed in the current scope of the test.
My colleague Matt Parker recently wrote about how Cucumber steps as teleportation devices and that same thinking applies here. To make the most of this these wordy methods should be considered jumping points into your testing DSLs.
For a more detailed example, check out the Simple BDD example project.