RSpec – Helpers
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Sometimes your RSpec examples need an easy way to share reusable code. The best way to accomplish this is with Helpers. Helpers are basically regular Ruby methods which you share across examples. To illustrate the benefit of using helpers, let’s consider this code −
class Dog attr_reader :good_dog, :has_been_walked def initialize(good_or_not) @good_dog = good_or_not @has_been_walked = false end def walk_dog @has_been_walked = true end end describe Dog do it ''should be able to create and walk a good dog'' do dog = Dog.new(true) dog.walk_dog expect(dog.good_dog).to be true expect(dog.has_been_walked).to be true end it ''should be able to create and walk a bad dog'' do dog = Dog.new(false) dog.walk_dog expect(dog.good_dog).to be false expect(dog.has_been_walked).to be true end end
This code is clear, but it’s always a good idea to reduce repeated code whenever possible. We can take the above code and reduce some of this repetition with a helper method called create_and_walk_dog().
class Dog attr_reader :good_dog, :has_been_walked def initialize(good_or_not) @good_dog = good_or_not @has_been_walked = false end def walk_dog @has_been_walked = true end end describe Dog do def create_and_walk_dog(good_or_bad) dog = Dog.new(good_or_bad) dog.walk_dog return dog end it ''should be able to create and walk a good dog'' do dog = create_and_walk_dog(true) expect(dog.good_dog).to be true expect(dog.has_been_walked).to be true end it ''should be able to create and walk a bad dog'' do dog = create_and_walk_dog(false) expect(dog.good_dog).to be false expect(dog.has_been_walked).to be true end end
When you run the above code, you will see this output −
.. Finished in 0.002 seconds (files took 0.11401 seconds to load) 2 examples, 0 failures
As you can see, we were able to push the logic for creating and walking a dog object into a Helper which allows our examples to be shorter and cleaner.
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