Set inverse of draft and published_revision associations on entry

This enables an edge-case where the account of an example entry is
changed transiently before creating a theme customization
preview. Make sure feature flags of the account are taken into account
correctly.

Generally, this should be an improvement since draft and published
revisions no longer need to look up there entries in a separate query.

REDMINE-20474

app/models/pageflow/entry.rb

@@ -29,8 +29,8 @@ class PasswordMissingError < StandardError
 
     has_many :imports, class_name: 'Pageflow::FileImport', dependent: :destroy
 
-    has_one :draft, -> { editable }, :class_name => 'Revision'
-    has_one :published_revision, -> { published }, :class_name => 'Revision'
+    has_one :draft, -> { editable }, class_name: 'Revision', inverse_of: :entry
+    has_one :published_revision, -> { published }, class_name: 'Revision', inverse_of: :entry
 
     has_one :edit_lock, :dependent => :destroy
 

spec/models/pageflow/entry_spec.rb

@@ -82,6 +82,22 @@ module Pageflow
       end
     end
 
+    describe '#draft' do
+      it 'sets inverse of association' do
+        entry = create(:entry)
+
+        expect(entry.draft.entry).to be(entry)
+      end
+    end
+
+    describe '#published_revision' do
+      it 'sets inverse of association' do
+        entry = create(:entry, :published)
+
+        expect(entry.published_revision.entry).to be(entry)
+      end
+    end
+
     describe '#entry_type' do
       it 'returns entry type' do
         pageflow_configure do |config|

spec/models/pageflow/revision_spec.rb

@@ -632,9 +632,26 @@ module Pageflow
           config.themes.register(:named_theme)
         end
 
-        site = build(:revision, theme_name: 'named_theme')
+        revision = build(:revision, theme_name: 'named_theme')
 
-        expect(site.theme.name).to eq('named_theme')
+        expect(revision.theme.name).to eq('named_theme')
+      end
+
+      it 'honors feature flags of transiently set account' do
+        pageflow_configure do |config|
+          config.themes.register(:some_theme, some: :option)
+
+          config.features.register('override_theme') do |feature_config|
+            feature_config.themes.register(:some_theme, some: :override)
+          end
+        end
+
+        entry = create(:entry, draft_attributes: {theme_name: 'some_theme'})
+        account_with_feature_flag = create(:account, with_feature: 'override_theme')
+
+        entry = Entry.find(entry.id)
+        entry.account = account_with_feature_flag
+        expect(entry.draft.theme.options[:some]).to eq(:override)
       end
     end