Added

• New extension for RSpec (@flash-gordon in #183): One of the pain points of testing monads is referencing class constants from specs. This extension catches missing class constants, analyzes the call site and returns a matching constant.

  Before, this code would raise a NameError because Failure is a constant that is missing in Object:

  example "missing constant" do
    expect(call_operation).to eql(Failure[:some_error, "some message"])
  end
  

  Now, after enabling the extension, it will return the correct constant:

  Dry::Monads.load_extensions(:rspec)
  
  example "missing constant" do
    Failure[:some_error, "some message"] # => Failure[:some_error, "some message"]
  end
  

  Out of the box, the extension will check if Success, Failure, Some, and None are referenced from a file ending with _spec.rb.

  More involved analysis is possible if you add debug_inspector to your Gemfile:

  group :test do
    gem "debug_inspector"
  end