users_controller_test.rb

class UsersControllerTest
  # With context
  context "on GET show, given the user exists" do
    setup do
      @user = Factory.stub(:user)
      User.stubs(:find => @user)
      get :show, :id => @user.to_param
    end

    should_respond_with :success
    should_render_template :show

    should "find the user" do
      assert_received(User, :find) {|expect| expect.with(@user.to_param) }
    end

    should "display the user's email" do
      assert_contain @user.email
    end
  end

  # Flat
  should "display the user on GET show for an existing user" do
    user = Factory.stub(:user)
    User.stubs(:find => user)

    get :show, :id => user.to_param

    assert_received(User, :find) {|expect| expect.with(user.to_param) }
    assert_response :success
    assert_template :show
    assert_contain user.email
  end
end

# One context per action
describe UsersController, "on GET show, given the user exists" do
  before do
    @user = Factory.stub(:user)
    User.stubs(:find => @user)
    get :show, :id => @user.to_param
  end

  it { should respond_with(:success) }
  it { should render_template(:show) }

  it "should find the user" do
    User.should have_received(:find).with(@user.to_param)
  end
end

# One test method per action
describe UsersController do
  it "should display the user on GET show for an existing user" do
    user = Factory.stub(:user)
    User.stubs(:find => user)

    get :show, :id => user.to_param

    User.should have_received(:find).with(user.to_param)
    should respond_with(:success)
    should render_template(:show)
  end
end

# Independent view test
describe "/users/show" do
  before do
    assigns[:user] = Factory.stub(:user)
    render "/users/show"
  end

  it "should display the user's email" do
    template.should contain(assigns[:user].email)
  end
end