basic_rednering_test.rb

class TestController < ActionController::Base
  protect_from_forgery

  def render_string_hello_world
    render "Hello world!"
  end

  def render_text_hello_world
    render :text => "hello world"
  end
end

class RenderTest < ActionController::TestCase
  tests TestController

  def test_render_string
    get :hello_world
    assert_response 200
    assert_response :success
    assert_equal "Hello world!", @response.body
  end

  def test_render_option_text
    get :render_text_hello_world
    assert_equal "hello world", @response.body
  end
end