undefined method `formats=' for ... Controller:Class

Question

I'm trying to send a 'delete' request with rspec. The problem is that I'm getting the following error :

undefined method `formats=' for Admin::CountriesController:Class

Here is my code :

describe 'Admin user deletion button' do
  def sign_in(user)
    user.confirm!
    visit '/login'
    fill_in 'user_email', with: user.email
    fill_in 'user_password', with: user.password
    click_button 'login_submit'
  end

  it 'should display an error' do
      @controller = Admin::UsersController
      @admin = FactoryGirl.create(:admin)

      sign_in @admin
      delete :delete, user_id: -1
    end
end

EDIT : Here is the full error :

1) Admin user deletion button with existing user should display an error Failure/Error: delete :delete, user_id: -1 NoMethodError: undefined method 'formats=' for Admin::UsersController:Class # ./spec/controllers/admin_user_deletion_spec.rb:51:in `block (3 levels) in '

EDIT 2 : Here is the controller code :

module Admin
# Controller for users admin panel
class UsersController < AdminController
  include UserHelper

  before_action :actual_user

  def users
    @users = User.normals.page(params[:users_page])
    @admins = User.admins.page(params[:admins_page])
  end

  def new
    @user = User.new
    render :new_user
  end

  def create
    user = User.new(user_params)

    if user.save
      flash[:notice] = "L'utilisateur #{user.name} a bien été creé"
    else
      flash[:alert] = "L'utilisateur n'a pas pu être créé"
    end
    redirect_to action: :users
  end

  def edit
    render :edit_user
  end

  def update
    if @user.update(user_params) && @user.confirm!
      flash[:notice] = "L'utilisateur #{@user.name} a bien été mis à jour"
    else
      flash[:alert] = "L'utilisateur #{@user.name} n'a pas pu être mis à jour"
    end
    redirect_to action: :users
  end

  def delete
    name = @user.name

    if @user.destroy
      flash[:notice] = "L'utilisateur #{name} a bien été supprimé"
    else
      flash[:alert] = "L'utilisateur #{name} n'a pas pu être supprimé"
    end
    redirect_to action: :users
  end

  private

  def user_params
    params[:user].delete(:password) if params[:user][:password].blank?
    params.require(:user).permit!
  end

  def actual_user
    @user = User.find(params[:user_id]) if params[:user_id]
  end
end
end

Answer 1

1. Never get involved in a land war in Asia.
2. Never go against a Sicilian when death is on the line.
3. Never confuse a controller spec and a feature spec.

Controller specs make assumptions about their prerequisites--feature specs don't. You have confused the two, a common mistake.

You should never use visit in a controller spec. Instead, pass the request parameters and (if necessary) session data in the call to the action itself.

As to why your request fails, consider the error message:

NoMethodError: undefined method 'formats=' for Admin::UsersController:Class

This is because you have redefined the controller instance variable and assigned it the controller class, instead of a controller instance. Instead, leave the controller instance variable alone and allow RSpec to call the action on the instance.

If you need further convincing, check the return value of @controller.respond_to?(:formats=) within the context of a spec; in your version this returns false, but in a standard controller spec (e.g. one created by the RSpec generator), this will return true.