Pending dashboard

This commit adds a simple admin-only "pending" dashboard to make it
easier and less error-prone to review albums that have been submitted
for publication.

I've decided to namespace the new controller under `admin` rather than
reuse the existing album controller for this.

Fixes #105

app/controllers/admin/albums_controller.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module Admin
+  class AlbumsController < ApplicationController
+    def index
+      authorize([:admin, Album])
+    end
+  end
+end

app/models/album.rb

@@ -28,6 +28,7 @@ class Album < ApplicationRecord
 
   scope :published, -> { where(publication_status: :published) }
   scope :unpublished, -> { where(publication_status: :unpublished) }
+  scope :pending, -> { where(publication_status: :pending) }
   scope :in_release_order, -> { order(Arel.sql('COALESCE(released_on, first_published_on) DESC NULLS LAST')) }
 
   after_commit :transcode_tracks, on: :update, if: :metadata_or_cover_changed?

app/policies/admin/album_policy.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module Admin
+  class AlbumPolicy < ApplicationPolicy
+    def index?
+      user.admin?
+    end
+  end
+end

app/views/admin/albums/index.html.erb

@@ -0,0 +1,8 @@
+<%= render('shared/page_header', text: 'Albums') %>
+<%= render('shared/page_sub_header', text: 'Pending') %>
+
+<ul>
+<% Album.pending.each do |album| %>
+<li><%= text_link_to "#{album.title} by #{album.artist.name}", artist_album_path(album.artist, album) %></li>
+<% end %>
+</ul>

app/views/shared/_page_sub_header.html.erb

@@ -0,0 +1 @@
+<h2 class="text-2xl tracking-tight leading-10 font-extrabold mb-3"><%= text %></h2>

config/routes.rb

@@ -32,6 +32,10 @@
     end
   end
 
+  namespace :admin do
+    resources 'albums', only: %i[index]
+  end
+
   resources :purchases, only: %i[show]
 
   resources :artists do

test/controllers/admin/albums_controller_test.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+module Admin
+  class AlbumsControllerTestSignedInAsAdmin < ActionDispatch::IntegrationTest
+    def setup
+      @album = create(:album, publication_status: :pending)
+      @user = create(:user, admin: true)
+      log_in_as(@user)
+    end
+
+    test '#index is authorized' do
+      get admin_albums_path
+      assert_response :success
+    end
+
+    test '#index lists pending albums' do
+      get admin_albums_path
+      assert_select 'li', text: "#{@album.title} by #{@album.artist.name}"
+    end
+  end
+
+  class AlbumsControllerTestSignedOut < ActionDispatch::IntegrationTest
+    test '#index is unauthorized' do
+      get admin_albums_path
+      assert_redirected_to log_in_url
+    end
+  end
+end

test/models/album_test.rb

@@ -168,6 +168,13 @@ class AlbumTest < ActiveSupport::TestCase
     assert_equal [unpublished_album], Album.unpublished
   end
 
+  test '.pending' do
+    create(:album)
+    create(:album, publication_status: :pending)
+
+    assert_equal 1, Album.pending.count
+  end
+
   test '.in_release_order' do
     create(:album, title: 'Unknown', released_on: nil)
     create(:album, title: 'Older Published', released_on: nil, first_published_on: Date.parse('2023-01-01'))

test/policies/admin/album_policy_test.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+module Admin
+  class AlbumPolicyTest < ActiveSupport::TestCase
+    test 'an admin' do
+      user = build(:user, admin: true)
+      album = build(:album)
+      policy = Admin::AlbumPolicy.new(user, album)
+
+      assert policy.index?
+    end
+  end
+end