session_test.rb

#!/usr/bin/ruby

require 'gems/environment'
require 'minitest/unit'
require 'minitest/spec'
require 'rack/test'
require 'sinatra/base'

ENV['RACK_ENV'] = 'test'

class MyApp < Sinatra::Base
  # enable :sessions
  get '/' do
    session[:user]
  end 
end

class MiniTest::Unit::TestCase
  include Rack::Test::Methods
  def app 
    MyApp
  end 
end

describe "Sinatra session test" do
  it "should pass session info" do
    get '/', {}, { "rack.session" => { user: 'dave' } } 
    assert_equal 'dave', last_response.body
  end 
end

MiniTest::Unit.autorun