RSpec documentation

RSpec is composed of multiple libraries, which are designed to work together, or can be used independently with other testing tools like Cucumber or Minitest.The parts of RSpec are:rspec-core: The spec runner, providing a rich command line program, flexible and customizable reporting, and an API to organize your code examples.rspec-expectations: Provides a readable API to express expected outcomes of a code example.rspec-mocks: Test double framework, providing multiple types of fake objects to allow you to tightly control the environment in which your specs run.rspec-rails: Supports using RSpec to test Ruby on Rails applications in place of Rails' built-in test framework.