fix(Page Cache Flushing): Only touch public page versions

We must not touch the draft versions, as we compare
the draft versions updated_at timestamp with the
public version in order to find out if there are
any unpublished changes.

(cherry picked from commit a014db2)

# Conflicts:
#	app/controllers/alchemy/admin/pages_controller.rb

Author: tvdeyen

app/controllers/alchemy/admin/pages_controller.rb

@@ -217,8 +217,7 @@ def copy_language_tree
       end
 
       def flush
-        @current_language.pages.touch_all
-        PageVersion.where(page_id: @current_language.pages.select(:id)).touch_all
+        PageVersion.where(page_id: @current_language.pages.select(:id)).published.touch_all
         respond_to { |format| format.js }
       end
 

spec/requests/alchemy/admin/pages_controller_spec.rb

@@ -227,29 +227,42 @@ module Alchemy
         let(:content_pages) { [content_page_1, content_page_2] }
         let(:layout_pages) { [layout_page_1, layout_page_2] }
 
-        it "should update the updated_at field of content pages" do
-          content_pages
+        it "should not update the updated_at field of pages" do
+          pages = content_pages + layout_pages
 
           travel_to(Time.current) do
-            post flush_admin_pages_path, xhr: true
-            # Reloading because updated_at was directly updated in the database.
-            content_pages.map(&:reload)
-            content_pages.each do |page|
-              expect(page.updated_at).to eq(Time.current)
-            end
+            expect {
+              post flush_admin_pages_path, xhr: true
+            }.to_not change {
+              # Reloading because updated_at was directly updated in the database.
+              pages.map { _1.reload.updated_at }
+            }
           end
         end
 
-        it "should update the updated_at field of layout pages" do
-          layout_pages
+        it "should update the updated_at field of public versions" do
+          page_versions = content_pages.filter_map(&:public_version)
 
           travel_to(Time.current) do
-            post flush_admin_pages_path, xhr: true
-            # Reloading because updated_at was directly updated in the database.
-            layout_pages.map(&:reload)
-            layout_pages.each do |page|
-              expect(page.updated_at).to eq(Time.current)
-            end
+            expect {
+              post flush_admin_pages_path, xhr: true
+            }.to change {
+              # Reloading because updated_at was directly updated in the database.
+              page_versions.map { _1.reload.updated_at }
+            }
+          end
+        end
+
+        it "should not update the updated_at field of draft versions" do
+          page_versions = content_pages.filter_map(&:draft_version)
+
+          travel_to(Time.current) do
+            expect {
+              post flush_admin_pages_path, xhr: true
+            }.to_not change {
+              # Reloading because updated_at was directly updated in the database.
+              page_versions.map { _1.reload.updated_at }
+            }
           end
         end
       end