Merge branch 'atomaka/feature/authorization' into 'master'

Add authorization via Pundit

Also includes some a refactor to null object pattern for guest users.

See merge request !24

.gitlab-ci.yml

@@ -4,4 +4,5 @@ test:
   - apt-get install -y nodejs libqtwebkit-dev qt4-qmake sqlite3 libsqlite3-dev
   - bundle install --path /cache
   - bundle exec rake db:create RAILS_ENV=test
+  - bundle exec rake db:test:prepare
   - bundle exec rspec

Gemfile

@@ -1,13 +1,5 @@
 source 'https://rubygems.org'
 
-def darwin_only(require_as)
-  RbConfig::CONFIG['host_os'] =~ /darwin/ && require_as
-end
-
-def linux_only(require_as)
-  RbConfig::CONFIG['host_os'] =~ /linux/ && require_as
-end
-
 gem 'rails', '4.2.3'
 gem 'sqlite3'
 
@@ -25,6 +17,8 @@ gem 'ancestry'
 
 gem 'bcrypt'
 
+gem 'pundit'
+
 gem 'sdoc', '~> 0.4.0', group: :doc
 
 group :development do

Gemfile.lock

@@ -212,6 +212,8 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
+    pundit (1.0.1)
+      activesupport (>= 3.0.0)
     quiet_assets (1.1.0)
       railties (>= 3.1, < 5.0)
     rack (1.6.4)
@@ -387,6 +389,7 @@ DEPENDENCIES
   launchy
   metric_fu
   pry
+  pundit
   quiet_assets
   rails (= 4.2.3)
   rspec-rails
@@ -403,4 +406,4 @@ DEPENDENCIES
   uglifier (>= 1.3.0)
 
 BUNDLED WITH
-   1.10.5
+   1.10.6

app/controllers/application_controller.rb

@@ -6,10 +6,15 @@ class ApplicationController < ActionController::Base
   helper_method :current_session
   helper_method :logged_in?
 
+  include Pundit
+
+  rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized
+
   private
 
   def current_user
     @current_user ||= User.find(current_session[:user_id]) if current_session
+    @current_user ||= GuestUser.new
   end
 
   def current_session
@@ -17,6 +22,11 @@ class ApplicationController < ActionController::Base
   end
 
   def logged_in?
-    !!current_user
+    current_user.registered?
+  end
+
+  def user_not_authorized
+    flash[:alert] = 'You are not authorized to perform this action.'
+    redirect_to(request.referrer || root_path)
   end
 end

app/controllers/comments_controller.rb

@@ -3,22 +3,29 @@ class CommentsController < ApplicationController
   before_filter :set_comment, only: [:show, :edit, :update, :destroy]
   before_filter :set_post
   before_filter :set_subcreddit
+  after_action :verify_authorized
 
   def show
     @comments = @comment
                   .subtree
                   .includes(:post, :user)
                   .arrange(order: :created_at)
+
+    authorize @comment
   end
 
   def new
     @comment = Comment.new(params[:parent_id])
+
+    authorize @comment
   end
 
   def create
     @comment = @post.comments.build comment_params
     @comment.user = current_user
 
+    authorize @comment
+
     if @comment.save
       flash[:notice] = 'Comment saved'
     else
@@ -29,9 +36,12 @@ class CommentsController < ApplicationController
   end
 
   def edit
+    authorize @comment
   end
 
   def update
+    authorize @comment
+
     if @comment.update comment_params
       redirect_to subcreddit_post_path(@subcreddit, @post),
         notice: 'Comment updated'
@@ -41,6 +51,8 @@ class CommentsController < ApplicationController
   end
 
   def destroy
+    authorize @comment
+
     @comment.destroy
     redirect_to subcreddit_post_path(@subcreddit, @post),
       notice: 'Comment deleted'

app/controllers/posts_controller.rb

@@ -2,23 +2,32 @@
 class PostsController < ApplicationController
   before_filter :set_post, except: [:index, :new, :create]
   before_filter :set_subcreddit
+  after_action :verify_authorized
 
   def index
     @posts = Post.includes(:subcreddit, :user).all
+
+    authorize Post
   end
 
   def show
     @comments = @post.comments.includes(:user).arrange(order: :created_at)
+
+    authorize @post
   end
 
   def new
     @post = Post.new
+
+    authorize @post
   end
 
   def create
     @post = @subcreddit.posts.build(post_params)
     @post.user = current_user
 
+    authorize @post
+
     if @post.save
       redirect_to subcreddit_post_path(@subcreddit, @post),
         notice: 'Post created'
@@ -28,9 +37,12 @@ class PostsController < ApplicationController
   end
 
   def edit
+    authorize @post
   end
 
   def update
+    authorize @post
+
     if @post.update(post_params)
       redirect_to subcreddit_post_path(@subcreddit, @post),
         notice: 'Post was updated'
@@ -40,6 +52,8 @@ class PostsController < ApplicationController
   end
 
   def destroy
+    authorize @post
+
     @post.destroy
 
     redirect_to subcreddits_path(@subcreddit), notice: 'Post was deleted'

app/controllers/subcreddits_controller.rb

@@ -1,23 +1,32 @@
 # controllers/subcreddits_controller.rb
 class SubcredditsController < ApplicationController
   before_filter :set_subcreddit, only: [:show, :edit, :update]
+  after_action :verify_authorized
 
   def index
     @subcreddits = Subcreddit.all
+
+    authorize Subcreddit
   end
 
   def show
     @posts = @subcreddit.posts
+
+    authorize @subcreddit
   end
 
   def new
     @subcreddit = Subcreddit.new
+
+    authorize @subcreddit
   end
 
   def create
     @subcreddit = Subcreddit.new(create_subcreddit_params)
     @subcreddit.owner = current_user
 
+    authorize @subcreddit
+
     if @subcreddit.save
       redirect_to @subcreddit, notice: 'Subcreddit was created!'
     else
@@ -26,9 +35,12 @@ class SubcredditsController < ApplicationController
   end
 
   def edit
+    authorize @subcreddit
   end
 
   def update
+    authorize @subcreddit
+
     if @subcreddit.update(update_subcreddit_params)
       redirect_to @subcreddit, notice: 'Subcreddit was updated!'
     else

app/models/guest_user.rb

@@ -0,0 +1,6 @@
+# models/guest_user.rb
+class GuestUser
+  def registered?
+    false
+  end
+end

app/models/user.rb

@@ -15,6 +15,10 @@ class User < ActiveRecord::Base
   validates :username, presence: true, uniqueness: true, sluguuidless: true
   validates :password, length: { minimum: 8 }
 
+  def registered?
+    true
+  end
+
   private
 
   def downcase_email

app/policies/application_policy.rb

@@ -0,0 +1,37 @@
+# policies/application_policy.rb
+class ApplicationPolicy
+  attr_reader :user, :record
+
+  def initialize(user, record)
+    @user = user
+    @record = record
+  end
+
+  def index?
+    false
+  end
+
+  def show?
+    false
+  end
+
+  def create?
+    false
+  end
+
+  def new?
+    create?
+  end
+
+  def update?
+    false
+  end
+
+  def edit?
+    update?
+  end
+
+  def destroy?
+    false
+  end
+end

app/policies/comment_policy.rb

@@ -0,0 +1,22 @@
+# policies/comment_policy.rb
+class CommentPolicy < ApplicationPolicy
+  def index?
+    true
+  end
+
+  def show?
+    true
+  end
+
+  def create?
+    user.registered?
+  end
+
+  def update?
+    record.user == user
+  end
+
+  def destroy?
+    record.user == user
+  end
+end

app/policies/post_policy.rb

@@ -0,0 +1,22 @@
+# policies/post_policy.rb
+class PostPolicy < ApplicationPolicy
+  def index?
+    true
+  end
+
+  def show?
+    true
+  end
+
+  def create?
+    user.registered?
+  end
+
+  def update?
+    record.user == user
+  end
+
+  def destroy?
+    record.user == user
+  end
+end

app/policies/subcreddit_policy.rb

@@ -0,0 +1,18 @@
+# policies/subcreddit_policy.rb
+class SubcredditPolicy < ApplicationPolicy
+  def index?
+    true
+  end
+
+  def show?
+    true
+  end
+
+  def create?
+    user.registered?
+  end
+
+  def update?
+    record.owner == user
+  end
+end

app/views/application/_sidebar.html.slim

@@ -5,12 +5,14 @@
       button.btn.btn-default type="button"
         span.glyphicon.glyphicon-search aria-hidden="true"
 
+  - if policy(:post).new?
     - if @subcreddit && @subcreddit.id
       = link_to 'Submit a new link', new_subcreddit_post_path(@subcreddit), class: 'button btn btn-primary btn-block'
       = link_to 'Submit a new text post', new_subcreddit_post_path(@subcreddit), class: 'button btn btn-primary btn-block'
+  - if policy(:subcreddit).new?
     = link_to 'Create your own subcreddit', new_subcreddit_path, class: 'button btn btn-primary btn-block'
 
-  - if @subcreddit && @subcreddit.id
+  - if @subcreddit && @subcreddit.id && policy(@subcreddit).edit?
     .title Moderation Tools
     .box
       ul

app/views/comments/show.html.slim

@@ -3,7 +3,8 @@
 .alert.alert-info.in-page
   p you are viewing a single comment's thread.
   p #{link_to 'view the rest of the comments', subcreddit_post_path(@subcreddit, @post)} →
-= "Commenting as: #{current_user.username}"
+- if policy(:comment).new?
-== render 'comments/form', subcreddit: @subcreddit, post: @post, comment: @post.comments.build, parent: @comment
+  = "Commenting as: #{current_user.username}"
+  == render 'comments/form', subcreddit: @subcreddit, post: @post, comment: @post.comments.build, parent: @comment
 .comments.contents
   == nested_comments(@comments)

app/views/posts/show.html.slim

@@ -4,7 +4,8 @@
   .title= "all #{@post.comments_count} comments"
 - else
   .title= "no comments (yet)"
-= "Commenting as: #{current_user.username}"
+- if policy(:comment).new?
-== render 'comments/form', subcreddit: @subcreddit, post: @post, comment: @post.comments.build, parent: nil
+  = "Commenting as: #{current_user.username}"
+  == render 'comments/form', subcreddit: @subcreddit, post: @post, comment: @post.comments.build, parent: nil
 .comments.contents
   == nested_comments(@comments)

spec/controllers/application_controller_spec.rb

@@ -31,7 +31,7 @@ describe ApplicationController, type: :controller do
 
     context 'when not logged in' do
       it 'should return nil' do
-        expect(controller.send(:current_user)).to be_nil
+        expect(controller.send(:current_user)).to be_a(GuestUser)
       end
     end
   end

spec/controllers/comments_controller_spec.rb

@@ -99,7 +99,8 @@ describe CommentsController, type: :controller do
   end
 
   describe '#edit' do
-    let!(:comment) { create(:comment) }
+    context 'when owner' do
+      let!(:comment) { create(:comment, user: user) }
       before(:each) do
         get :edit,
           id: comment,
@@ -117,12 +118,15 @@ describe CommentsController, type: :controller do
         end
       end
     end
+  end
 
   context '#update' do
-    let!(:comment) { create(:comment) }
     let(:data) { { content: 'Some edited comment content goes here' } }
 
     context 'with valid data' do
+      let!(:comment) { create(:comment, user: user) }
+
+      context 'when owner' do
         before(:each) do
           put :update,
             id: comment,
@@ -166,9 +170,11 @@ describe CommentsController, type: :controller do
         end
       end
     end
+  end
 
   context '#destroy' do
-    let!(:comment) { create(:comment) }
+    context 'when owner' do
+      let!(:comment) { create(:comment, user: user) }
 
       it 'should delete the post' do
         delete :destroy,
@@ -186,7 +192,8 @@ describe CommentsController, type: :controller do
           post_id: comment.post,
           subcreddit_id: comment.post.subcreddit
 
-      expect(response).to redirect_to(subcreddit_post_path(assigns(:subcreddit),
+        expect(response)
+          .to redirect_to(subcreddit_post_path(assigns(:subcreddit),
                                                assigns(:post)))
       end
 
@@ -198,4 +205,5 @@ describe CommentsController, type: :controller do
         expect(flash[:notice]).to be_present
       end
     end
+  end
 end

spec/controllers/posts_controller_spec.rb

@@ -94,7 +94,8 @@ describe PostsController, type: :controller do
   end
 
   context '#edit' do
-    let!(:post) { create(:post) }
+    context 'when owner' do
+      let!(:post) { create(:post, user: user) }
       before(:each) { get :edit, id: post, subcreddit_id: post.subcreddit }
 
       context 'with valid post' do
@@ -107,9 +108,9 @@ describe PostsController, type: :controller do
         end
       end
     end
+  end
 
   context '#update' do
-    let!(:post) { create(:post) }
     let(:data) do
       {
         title: 'New title',
@@ -117,6 +118,9 @@ describe PostsController, type: :controller do
       }
     end
 
+    context 'when owner' do
+      let!(:post) { create(:post, user: user) }
+
       context 'with valid data' do
         before(:each) do
           put :update, id: post, subcreddit_id: post.subcreddit, post: data
@@ -154,9 +158,11 @@ describe PostsController, type: :controller do
         end
       end
     end
+  end
 
   context '#destroy' do
-    let!(:post) { create(:post, subcreddit: subcreddit) }
+    context 'when owner' do
+      let!(:post) { create(:post, user: user, subcreddit: subcreddit) }
 
       it 'should delete the post' do
         expect { delete :destroy, subcreddit_id: subcreddit, id: post }
@@ -174,4 +180,5 @@ describe PostsController, type: :controller do
         expect(flash[:notice]).to be_present
       end
     end
+  end
 end

spec/controllers/subcreddits_controller_spec.rb

@@ -97,7 +97,8 @@ describe SubcredditsController, type: :controller do
 
   describe '#edit' do
     context 'with valid subcreddit' do
-      let(:subcreddit) { create(:subcreddit) }
+      context 'when owner' do
+        let(:subcreddit) { create(:subcreddit, owner: user) }
 
         it 'should assign @subcreddit to the existing subcreddit' do
           get :edit, id: subcreddit
@@ -112,9 +113,9 @@ describe SubcredditsController, type: :controller do
         end
       end
     end
+  end
 
   describe '#update' do
-    let(:subcreddit) { create(:subcreddit) }
     let(:data) do
       {
         closed: '1'
@@ -122,6 +123,9 @@ describe SubcredditsController, type: :controller do
     end
 
     context 'wth valid data' do
+      context 'when owner' do
+        let(:subcreddit) { create(:subcreddit, owner: user) }
+
         it 'should assign @subcreddit to the existing subcreddit' do
           put :update, id: subcreddit, subcreddit: data
 
@@ -146,7 +150,6 @@ describe SubcredditsController, type: :controller do
 
           expect(flash[:notice]).to be_present
         end
-    end
 
         context 'with invalid data' do
           before(:each) { data[:closed] = 'bad' }
@@ -158,4 +161,6 @@ describe SubcredditsController, type: :controller do
           end
         end
       end
+    end
+  end
 end

spec/features/comments/edit_comment_spec.rb

@@ -3,15 +3,20 @@ require 'rails_helper'
 describe 'Edit Comment', type: :feature do
   let!(:user) { create(:user) }
   let!(:post) { create(:post) }
-  let!(:comment) { create(:comment, post: post, user: user) }
 
   context 'when signed in' do
-    let(:content) { 'Some different data' }
+    let!(:comment) { create(:comment, post: post, user: user) }
+
     before(:each) { signin(user: user) }
 
+    context 'when owner' do
+      let(:content) { 'Some different data' }
+
       context 'with valid data' do
         before(:each) do
-        visit edit_subcreddit_post_comment_path(post.subcreddit, post, comment)
+          visit edit_subcreddit_post_comment_path(post.subcreddit,
+                                                  post,
+                                                  comment)
 
           fill_in :comment_content, with: content
 
@@ -27,4 +32,25 @@ describe 'Edit Comment', type: :feature do
         end
       end
     end
+
+    context 'when not owner' do
+      let!(:comment) { create(:comment, post: post) }
+
+      it 'should not allow editing of comment' do
+        visit edit_subcreddit_post_comment_path(post.subcreddit, post, comment)
+
+        expect(page).to have_content('not authorized')
+      end
+    end
+  end
+
+  context 'when not signed in' do
+    let!(:comment) { create(:comment, post: post) }
+
+    it 'should not allow editing of comment' do
+      visit edit_subcreddit_post_comment_path(post.subcreddit, post, comment)
+
+      expect(page).to have_content('not authorized')
+    end
+  end
 end

spec/features/posts/edit_post_spec.rb

@@ -1,14 +1,17 @@
 require 'rails_helper'
 
 describe 'Edit Post', type: :feature do
+  let!(:subcreddit) { create(:subcreddit) }
+
   context 'when signed in' do
     let!(:user) { create(:user) }
-    let!(:subcreddit) { create(:subcreddit) }
-    let!(:post) { create(:post, subcreddit: subcreddit, user: user) }
     let(:new_post) { build_stubbed(:post) }
 
     before(:each) { signin(user: user) }
 
+    context 'when owner' do
+      let!(:post) { create(:post, subcreddit: subcreddit, user: user) }
+
       context 'with valid data' do
         before(:each) do
           visit edit_subcreddit_post_path(subcreddit, post)
@@ -30,4 +33,26 @@ describe 'Edit Post', type: :feature do
         end
       end
     end
+
+    context 'when not owner' do
+      let!(:post) { create(:post, subcreddit: subcreddit) }
+
+      it 'should notify user that they cannot edit' do
+        visit edit_subcreddit_post_path(subcreddit, post)
+
+        expect(page).to have_content 'not authorized'
+      end
+    end
+  end
+
+  context 'when not signed in' do
+    let!(:user) { GuestUser.new }
+    let!(:post) { create(:post, subcreddit: subcreddit) }
+
+    it 'should notify user they cannot edit' do
+      visit edit_subcreddit_post_path(subcreddit, post)
+
+      expect(page).to have_content 'not authorized'
+    end
+  end
 end

spec/features/posts/new_post_spec.rb

@@ -1,9 +1,10 @@
 require 'rails_helper'
 
 describe 'New Post', type: :feature do
+  let!(:subcreddit) { create(:subcreddit) }
+
   context 'when signed in' do
     let!(:user) { create(:user) }
-    let!(:subcreddit) { create(:subcreddit) }
     let!(:post) { build(:post, subcreddit: subcreddit) }
 
     before(:each) { signin(user: user) }
@@ -46,4 +47,15 @@ describe 'New Post', type: :feature do
       end
     end
   end
+
+  context 'when not signed in' do
+    let!(:user) { GuestUser.new }
+    let!(:post) { create(:post, subcreddit: subcreddit) }
+
+    it 'should notify user they cannot create' do
+      visit new_subcreddit_post_path(subcreddit)
+
+      expect(page).to have_content 'not authorized'
+    end
+  end
 end

spec/features/subcreddits/close_subcreddit_spec.rb

@@ -4,8 +4,13 @@ describe 'Edit Subcreddit', type: :feature do
   before(:each) { signout }
 
   context 'when logged in' do
+    let!(:user) { create(:user) }
+    before(:each) { signin(user: user) }
+
+    context 'when user is owner' do
+      let!(:subcreddit) { create(:subcreddit, owner: user) }
+
       context 'when board is open' do
-      let!(:subcreddit) { create(:subcreddit) }
         before(:each) do
           visit subcreddits_path
           click_link 'Edit'
@@ -23,7 +28,10 @@ describe 'Edit Subcreddit', type: :feature do
       end
 
       context 'when board is closed' do
-      let!(:subcreddit) { create(:subcreddit, closed_at: Time.now) }
+        let!(:subcreddit) do
+          create(:subcreddit, owner: user, closed_at: Time.now)
+        end
+
         before(:each) do
           visit subcreddits_path
           click_link 'Edit'
@@ -36,4 +44,20 @@ describe 'Edit Subcreddit', type: :feature do
         end
       end
     end
+
+    context 'when not owner' do
+      let!(:subcreddit) { create(:subcreddit) }
+
+      it 'should not allow editing of subcreddit' do
+        visit subcreddits_path
+        click_link 'Edit'
+
+        expect(page).to have_content('not authorized')
+      end
+    end
+  end
+
+  context 'when not logged in' do
+
+  end
 end

spec/features/subcreddits/new_subcreddit_spec.rb

@@ -4,7 +4,11 @@ describe 'New Subcreddit', type: :feature do
   before(:each) { signout }
 
   context 'when not signed in' do
-    it 'should not be able to create a new subcreddit'
+    it 'should not be able to create a new subcreddit' do
+      visit new_subcreddit_path
+
+      expect(page).to have_content('not authorized')
+    end
   end
 
   context 'when signed in' do

spec/policies/application_policy_spec.rb

@@ -0,0 +1,15 @@
+require 'rails_helper'
+
+describe ApplicationPolicy do
+  subject { ApplicationPolicy.new(user, object) }
+  let(:user) { create(:user) }
+  let(:object) { double('Object') }
+
+  it { should_not grant(:index) }
+  it { should_not grant(:show) }
+  it { should_not grant(:new) }
+  it { should_not grant(:create) }
+  it { should_not grant(:edit) }
+  it { should_not grant(:update) }
+  it { should_not grant(:destroy) }
+end

spec/policies/comment_policy_spec.rb

@@ -0,0 +1,48 @@
+require 'rails_helper'
+
+describe CommentPolicy do
+  subject { CommentPolicy.new(user, comment) }
+
+  context 'when user is a guest' do
+    let(:comment) { create(:comment) }
+    let(:user) { GuestUser.new }
+
+    it { should grant(:index) }
+    it { should grant(:show) }
+
+    it { should_not grant(:new) }
+    it { should_not grant(:create) }
+    it { should_not grant(:edit) }
+    it { should_not grant(:update) }
+    it { should_not grant(:destroy) }
+  end
+
+  context 'when user is registered' do
+    let(:user) { create(:user) }
+
+    context 'when not owner' do
+      let(:comment) { create(:comment) }
+
+      it { should grant(:index) }
+      it { should grant(:show) }
+      it { should grant(:new) }
+      it { should grant(:create) }
+
+      it { should_not grant(:edit) }
+      it { should_not grant(:update) }
+      it { should_not grant(:destroy) }
+    end
+
+    context 'when owner' do
+      let(:comment) { create(:comment, user: user) }
+
+      it { should grant(:index) }
+      it { should grant(:show) }
+      it { should grant(:new) }
+      it { should grant(:create) }
+      it { should grant(:edit) }
+      it { should grant(:update) }
+      it { should grant(:destroy) }
+    end
+  end
+end

spec/policies/post_policy_spec.rb

@@ -0,0 +1,48 @@
+require 'rails_helper'
+
+describe PostPolicy do
+  subject { PostPolicy.new(user, post) }
+
+  context 'when user is a guest' do
+    let(:post) { create(:post) }
+    let(:user) { GuestUser.new }
+
+    it { should grant(:index) }
+    it { should grant(:show) }
+
+    it { should_not grant(:new) }
+    it { should_not grant(:create) }
+    it { should_not grant(:edit) }
+    it { should_not grant(:update) }
+    it { should_not grant(:destroy) }
+  end
+
+  context 'when user is registered' do
+    let(:user) { create(:user) }
+
+    context 'when not owner' do
+      let(:post) { create(:post) }
+
+      it { should grant(:index) }
+      it { should grant(:show) }
+      it { should grant(:new) }
+      it { should grant(:create) }
+
+      it { should_not grant(:edit) }
+      it { should_not grant(:update) }
+      it { should_not grant(:destroy) }
+    end
+
+    context 'when owner' do
+      let(:post) { create(:post, user: user) }
+
+      it { should grant(:index) }
+      it { should grant(:show) }
+      it { should grant(:new) }
+      it { should grant(:create) }
+      it { should grant(:edit) }
+      it { should grant(:update) }
+      it { should grant(:destroy) }
+    end
+  end
+end

spec/policies/subcreddit_policy_spec.rb

@@ -0,0 +1,49 @@
+require 'rails_helper'
+
+describe SubcredditPolicy do
+  subject { SubcredditPolicy.new(user, subcreddit) }
+
+  context 'when user is a guest' do
+    let(:subcreddit) { create(:subcreddit) }
+    let(:user) { GuestUser.new }
+
+    it { should grant(:index) }
+    it { should grant(:show) }
+
+    it { should_not grant(:new) }
+    it { should_not grant(:create) }
+    it { should_not grant(:edit) }
+    it { should_not grant(:update) }
+    it { should_not grant(:destroy) }
+  end
+
+  context 'when user is registered' do
+    let(:user) { create(:user) }
+
+    context 'when not owner' do
+      let(:subcreddit) { create(:subcreddit) }
+
+      it { should grant(:index) }
+      it { should grant(:show) }
+      it { should grant(:new) }
+      it { should grant(:create) }
+
+      it { should_not grant(:edit) }
+      it { should_not grant(:update) }
+      it { should_not grant(:destroy) }
+    end
+
+    context 'when owner' do
+      let(:subcreddit) { create(:subcreddit, owner: user) }
+
+      it { should grant(:index) }
+      it { should grant(:show) }
+      it { should grant(:new) }
+      it { should grant(:create) }
+      it { should grant(:edit) }
+      it { should grant(:update) }
+
+      it { should_not grant(:destroy) }
+    end
+  end
+end

spec/rails_helper.rb

@@ -12,11 +12,13 @@ require 'rspec/rails'
 require 'shoulda/matchers'
 require 'capybara/rails'
 require 'capybara/rspec'
+require 'pundit/rspec'
 
 require 'support/capybara'
 require 'support/database_cleaner'
 require 'support/factory_girl'
 require 'support/helpers'
+require 'support/pundit_matcher'
 
 ActiveRecord::Migration.maintain_test_schema!
 

spec/support/pundit_matcher.rb

@@ -0,0 +1,15 @@
+RSpec::Matchers.define :grant do |action|
+  match do |policy|
+    policy.public_send("#{action}?")
+  end
+
+  failure_message do |policy|
+    "#{policy.class} does not permit #{action} on #{policy.record} "
+    + "for #{policy.user.inspect}."
+  end
+
+  failure_message_when_negated do |policy|
+    "#{policy.class} does not forbid #{action} on #{policy.record} "
+    + "for #{policy.user.inspect}."
+  end
+end