litmus_test.rb

require 'httparty'

class LitmusTest
  include HTTParty
  base_uri('https://api.litmus.com/v2')
  basic_auth('<YOUR API KEY>', 'x')
  headers({'Content-Type' => 'application/json'})

  def self.create(subject, body)
    post('/emails', :body => {:email => {:name => "#{subject} @ #{Time.now.to_s(:short)}", :subject => subject, :body => body, :client_ids => self.client_ids}}.to_json)
  end

  # Cache the client_id list per test suite.
  def self.client_ids
    @@client_ids ||= get('/emails/clients')['clients'].map { |client| client['id'] }
  end
end

spec_helper.rb

def write_output_to_file(subject, body)
  if ENV['LITMUS']
    puts "Posting email to Litmus:"
    test = LitmusTest.create(subject, body)
    puts "Created Litmus Test: #{test.body}"
  end
end