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36 CHAPTER 2 Testing saves your bacon
Cucumber’s history is intertwined with RSpec, so the two are similar. In the beginning
of BDD, as you know, there was RSpec. Shortly thereafter, there were RSpec Stories,
which looked like the following listing.
Listing 2.19 Example
Scenario "savings account is in credit" do
Given "my savings account balance is", 100 do |balance|
@account = Account.new(balance)
end
...
end
The idea behind RSpec Stories is that they are code- and human-readable stories that
can be used for automated testing as well as quality assurance (QA) testing by stakeholders.
Aslak Hellesoy rewrote RSpec Stories during October 2008 into what we
know today as Cucumber. The syntax remains similar, as seen in the following listing.
Listing 2.20 Example
Scenario: Taking out money
Given I have an account
And my account balance is 100
When I take out 10
Then my account balance should be 90
What you see here is known as a scenario in Cucumber. Under the scenario’s title, the
remainder of the lines are called steps, which are read by Cucumber’s parser and
matched to step definitions, where the logic is kept. Scenarios are found inside a feature,
which is a collection of common scenarios. For example, you may have one feature for
dictating what happens when a user creates projects and another for when a user creates
tickets.
Notice the keywords Given, And, When, and Then. These are just some of the keywords
that Cucumber looks for to indicate that a line is a step. If you’re going to be
using the same keyword on a new line, it’s best practice to instead use the And keyword
because it reads better. Try reading the first two lines aloud from the previous listing,
then replace the And with Given and try it again. It just sounds right to have an And
there rather than a Given.
Given steps are used for setting up the scene for the scenario. This example sets up
an account and gives it a balance of 100.
When steps are used for defining actions that should happen during the scenario.
The example says, When I take out 10.
Then steps are used for declaring things that take place after the When steps have
completed. This example says, When I take out 10 Then my account balance should
be 90.
These different step types add a great deal of human readability to the scenarios in
which they’re used, even though they can be used interchangeably. You could define