extract.rb

require 'minitest/spec'
require 'minitest/autorun'

class Credentials < Struct.new(:login, :password) ; end

class EnvironmentCredentials < Credentials
  def initialize()
    super(ENV['USER'], ENV['PASSWORD'])
  end
end

class SandboxCredentials < Credentials
  def initialize()
    super('SandboxUser', 'Password1')
  end
end

module Addressable
  class URI
    attr_accessor :query_values

    def self.parse input
      URI.new
    end
  end
end

class ApiProvider
  attr_accessor :uri

  def initialize(credentials)
    @uri = Addressable::URI.parse("http://api.example.org/query")
    @uri.query_values = {usr: credentials.login, pwd: credentials.password}
  end
end

describe "Environment Credentials" do
  before do
    @old_user = ENV['USER']
    @old_password = ENV['PASSWORD']
  end

  after do
    ENV['USER'] = @old_user unless @old_user.nil?
    ENV['PASSWORD'] = @old_password unless @old_password.nil?
  end

  it "should get it's values from the environment" do
    ENV['USER'] = 'UserBlahBlah'
    ENV['PASSWORD'] = 'PasswordLaLa'

    credentials = EnvironmentCredentials.new

    assert_equal 'UserBlahBlah', credentials.login
    assert_equal 'PasswordLaLa', credentials.password
  end
end

describe "creation" do
  it "requires credentials" do
    assert_raises ArgumentError do
      ApiProvider.new
    end
  end

  it "sets user and password query values on creation" do
    provider = ApiProvider.new SandboxCredentials.new

    assert_equal 'SandboxUser', provider.uri.query_values[:usr]
    assert_equal 'Password1', provider.uri.query_values[:pwd]
  end
end