We are going to work with ruby cucumber so, if you don't have ruby installed this is a goos moment to do it. You can easily get ruby by using RVM (it is a tool similar to nvm). Run the following commands:
\curl -sSL https://get.rvm.io | bash
rvm install 2.5.1
Clone this repository to start working on it
git clone https://github.com/cabify/slice_of_cucumber.git
Now we'll install Bundler
gem install bundler
And finally, cucumber itself (we are adding cucumber as a dependency to the Gemfile in the project):
bundle add cucumber
We should now be able to execute cucumber, do it. You should get an output similar to this
No such file or directory - features. You can use `cucumber --init` to get started.
So let's do what cucumber is telling us to.
cucumber --init
The following folder structure has been added to our project (we'll start working on it right now).
features
|_ step_definitions
|_ support
|_ env.rb
If we run cucumber now, the tool will tell us there is nothing for it to execute
0 scenarios
0 steps
0m0.000s
Good question.
Cucumber is a software tool that executes behaviour specifications written in a near-to-natural language called Gherkin.
In other words, you write software behaviour in a language similar to plain english (there are a couple of rules you must follow, we'll see them soon), save it to a file and tell cucumber to execute it. And cucumber does it (at least it tries).
This is an example of one of those files:
Feature: Is it Friday yet?
Everyone in the office wants to know when it's Friday.
Which are the rules to know when it's Friday?
Scenario: Monday isn't Friday
Given today is Monday
When I ask whether it's Friday yet
Then I should be told "No"
In fact, in this file there are keywords that cucumber uses to parse the information, and execute a Scenario (a specific example about how the described system must behave). This Scenario is composed by different Steps (those Given, When and Then lines) which in fact will be executed sequentially by cucumber.
Ok, let's try this.