Testing standard input with RSpec

spec_helper.rb

module Helpers
  # Replace standard input with faked one StringIO. 
  def stdin_send(*args)
    begin
      $stdin = StringIO.new
      $stdin.puts(args.shift) until args.empty?
      $stdin.rewind
      yield
    ensure
      $stdin = STDIN
    end
  end
end

RSpec.configure do |c|
  c.include(Helpers)
end

stdin_spec.rb

require "spec_helper"

describe "standard input" do 
  it "should receive `foobar`" do
    stdin_send("foobar") do 
      input = gets.to_s.chomp.strip
      expect(input).to eq "foobar"
    end
  end
end