Example functional test for a Rails 2.3 application

test_helper.rb

class ActiveSupport::TestCase
  def login_as(user)
    @request.session[:user_id] = user ? users(user).id : nil
  end

  def current_user
    @current_user ||= User.find(@request.session[:user_id])
  end
end

users_controller_test.rb

require 'test_helper'

class UsersControllerTest < ActionController::TestCase
  
  def setup
    # most tests will run as monica
    login_as :monica
  end
  
  test "should get index" do
    get :index
    assert_response :success
  end
  
  test "should redirect to login form for user who does not have access to index" do
    # login as a user that does not have access to this action
    login_as :tiffany
    get :index
    assert_redirected_to new_session_path
  end
  
  test "should get new" do
    get :new
    assert_response :success
  end

  test "should create user" do
    assert_difference 'User.count' do
      post :create, :user => { :active => true, :email => 'tester@example.com', :first_name => 'Jon', :last_name => 'Tester', :password => 'password', :password_confirmation => 'password' }
    end
    
    # use assigns to access the instance variable setup by the controller
    assert_redirected_to user_path(assigns(:user))
  end

  test "should fail to create user" do
    assert_no_difference 'User.count' do
      post :create, :user => { :first_name => 'Jon' }
    end
    
    # with a validation error the action renders a template and results in a success instead of a redirect
    assert_response :success
  end
  
  test "should show user" do
    get :show, :id => users(:tiffany).id
    assert_response :success
  end

  test "should get edit" do
    get :edit, :id => users(:tiffany).id
    assert_response :success
  end

  test "should update user" do
    put :update, :id => users(:tiffany).id, :user => { :last_name => 'Tester' }
    assert_redirected_to user_path(assigns(:user))
  end
  
  test "should fail to update user" do
    put :update, :id => users(:tiffany).id, :user => { :last_name => '' }
    
    # with a validation error the action renders a template and results in a success instead of a redirect
    assert_response :success
  end

  test "should destroy user" do
    assert_difference 'User.count', -1 do
      delete :destroy, :id => users(:tiffany).id
    end

    assert_redirected_to users_path
  end
end