¿Cuál es el propósito de burlarse con RSpec?

What is the purpose of mocking with RSpec?

Mocking helps us by reducing the number of things we need to keep in our head at a given moment. Mocking with RSpec is done with the rspec-mocks gem. If you have rspec as a dependency in your Gemfile, you already have rspec-mocks available. A test double is a simplified object which takes the place of another object in a test.

Mocking with RSpec is done with the rspec-mocks gem. If you have rspec as a dependency in your Gemfile, you already have rspec-mocks available. A test double is a simplified object which takes the place of another object in a test. Creating a double with RSpec is easy: A new double resembles a plain Ruby Object — it’s not very useful on its own.

This method is hard to test because of the randomness. RSpec allows you to mock, or stub rand. rand returns a fixed value so you can use it for testing the outcome of your method. Ideally, you would want to inject your dependency (the rand function, in this case) so you can control it.

We also need a flip method: Now we get this feedback from RSpec: This is saying that the flip method was called 0 times, but it was expected to be called 1 time. .

A test double is a simplified object which takes the place of another object in a test. Creating a double with RSpec is easy: A new double resembles a plain Ruby Object — it’s not very useful on its own. It is usually the first step before defining some fake methods on it.

Mocking is a technique in test-driven development (TDD) that involves using fake dependent objects or methods in order to write a test. There are a couple of reasons why you may decide to use mock objects: As a replacement for objects that don’t exist yet.

When testing Rails applications, for example, it is common to mock a method which works with the database and make it return a predefined double whenever the focus of the code is not whether the database operations work or not (and the test can run faster too). We’ll see how we can apply this below.

The RSpec team actually officially discourages the use of controller specs, as well as adding the rails-controller-testing gem to your application; “The official recommendation of the Rails team and the RSpec core team is to write request specs instead.