ruby-on-rails - RSpec と Cancancan: すべてのネガティブ テストが失敗する

Question

なぜ私のネガティブ（つまり、should_not）テストだけが失敗するのかを理解するのを手伝ってくれる人はいますか? すべてのshouldテストに合格しているので、構成が間違っていると思いますが、何がわかりません。

アビリティ.rb

# encoding: utf-8
#
class Ability
  include CanCan::Ability

  def initialize(user)
    @user = user || User.new
    if @user.administrator?
      administrator_abilities
    elsif @user.client?
      client_abilities
    elsif @user.guest?
      guest_abilities
    end
    can :read, :share
  end

  private

  def administrator_abilities
    can :manage, :all
    can [:index, :filter, :new, :create], :administration
  end

  def client_abilities
    cannot :manage, administrator_resources
    can :manage, [:account, :provider_auth, :user_auth]
    can :read, [Component, Cover, Introduction, Template]
    can :manage, client_made_resources, user_id: @user.id
  end

  def guest_abilities
    cannot :manage, client_made_resources
    cannot :manage, administrator_resources
    can :create, Expression
  end

  def client_made_resources
    [Authorisation, Document, Component,
     CustomArticle, EditedArticle, Invoice, Order, Photo]
  end

  def administrator_resources
    [Brand, Chart, Component, Cover, Expression, Introduction, Mode,
     Preference, Price, Template, User, UserNote]
  end
end

user_spec.rb

# encoding: utf-8
#
require 'spec_helper'
require 'cancan/matchers'
def client_made_resources
  [Authorisation, Document, Component, CustomArticle, EditedArticle, Invoice,
   Order, Photo]
end

def administrator_resources
  [Brand, Chart, Component, Cover, Expression, Introduction, Mode, Preference,
   Price, Template, User, UserNote]
end

RSpec.describe Ability do
  let(:user) { create(:user, state: 'guest') }
  subject    { Ability.new(user) }

  context 'guest' do
    client_made_resources.each do |r|
      it "should not be able to manage client's #{r}" do
        expect(subject).to_not be_able_to(:manage, r.new)
      end
    end

すべての否定的なテストには、次の結果があります。

rspec ./spec/models/user_spec.rb:69 # Ability guest should not be able to manage client's Document

ご協力いただきありがとうございます。