Only publish manuals if its the correct version

As we are now queueing manuals for publishing we need to protect against changes happening between an editor clicking Publish and the worker actually performing the publish.

We also add the version number to the logs as its useful information to know about.

app/loggers/publication_logger.rb

@@ -9,6 +9,8 @@ def call
     manual.documents.each do |doc|
       PublicationLog.create!(
         title: doc.title,
+        manual_version_number: manual.version_number,
+        version_number: doc.version_number,
         slug: doc.slug,
         change_note: doc.change_note,
         document_state: state,

app/models/manual.rb

@@ -6,12 +6,14 @@ class Manual
     :summary,
     :organisation_slug,
     :state,
+    :version_number,
     :updated_at,
   )
 
   def initialize(attributes)
     @id = attributes.fetch(:id)
     @updated_at = attributes.fetch(:updated_at, nil)
+    @version_number = attributes.fetch(:version_number, 0)
 
     update(attributes)
   end
@@ -28,6 +30,7 @@ def attributes
       summary: summary,
       organisation_slug: organisation_slug,
       state: state,
+      version_number: version_number,
       updated_at: updated_at,
     }
   end

app/repositories/manual_repository.rb

@@ -65,6 +65,7 @@ def build_manual_for(manual_record)
       summary: edition.summary,
       organisation_slug: manual_record.organisation_slug,
       state: edition.state,
+      version_number: edition.version_number,
       updated_at: edition.updated_at,
     )
 

app/services/manual_service_registry.rb

@@ -1,9 +1,10 @@
 class ManualServiceRegistry
-  def publish(manual_id)
+  def publish(manual_id, version_number)
     PublishManualService.new(
       manual_repository: manual_repository,
       listeners: observers.publication,
       manual_id: manual_id,
+      version_number: version_number,
     )
   end
 

app/services/organisational_manual_service_registry.rb

@@ -38,14 +38,6 @@ def show(manual_id)
     )
   end
 
-  def publish(context)
-    PublishManualService.new(
-      manual_repository: manual_repository,
-      listeners: observers.publication,
-      context: context,
-    )
-  end
-
   def queue_publish(manual_id)
     QueuePublishManualService.new(
       async_services,

app/services/publish_manual_service.rb

@@ -3,18 +3,30 @@ def initialize(dependencies)
     @manual_id = dependencies.fetch(:manual_id)
     @manual_repository = dependencies.fetch(:manual_repository)
     @listeners = dependencies.fetch(:listeners)
+    @version_number = dependencies.fetch(:version_number)
   end
 
   def call
-    publish
-    persist
+    if versions_match?
+      publish
+      persist
+    end
 
     manual
   end
 
-  private
+private
+
+  attr_reader(
+    :manual_id,
+    :manual_repository,
+    :listeners,
+    :version_number,
+  )
 
-  attr_reader :manual_id, :manual_repository, :listeners
+  def versions_match?
+    version_number == manual.version_number
+  end
 
   def publish
     manual.publish

app/services/queue_publish_manual_service.rb

@@ -8,7 +8,7 @@ def initialize(async_services, repository, publication_logger, manual_id)
   end
 
   def call
-    async_services.publish(manual.id)
+    async_services.publish(manual.id, manual.version_number)
     publication_logger.call(manual).call
     manual
   end

app/workers/asynchronous_manual_service_registry.rb

@@ -1,6 +1,6 @@
 class AsynchronousManualServiceRegistry
 
-  def publish(id)
-    PublishManualWorker.perform_async(id)
+  def publish(id, version_number)
+    PublishManualWorker.perform_async(id, version_number)
   end
 end

app/workers/publish_manual_worker.rb

@@ -1,8 +1,8 @@
 class PublishManualWorker
   include Sidekiq::Worker
 
-  def perform(manual_id)
-    services.publish(manual_id).call
+  def perform(manual_id, version_number)
+    services.publish(manual_id, version_number).call
   end
 
 private

spec/models/manual_spec.rb

@@ -59,6 +59,7 @@
         organisation_slug: organisation_slug,
         state: state,
         updated_at: updated_at,
+        version_number: 0,
       )
     end
   end

spec/repositories/manual_repository_spec.rb

@@ -64,6 +64,7 @@
       organisation_slug: "organisation_slug",
       state: "draft",
       slug: manual_slug,
+      version_number: 1,
     }
   }
 

spec/services/publish_manual_service_spec.rb

@@ -0,0 +1,43 @@
+require "fast_spec_helper"
+require "publish_manual_service"
+
+RSpec.describe PublishManualService do
+
+  let(:manual_id) { double(:manual_id) }
+  let(:manual_repository) { double(:manual_repository) }
+  let(:listeners) { [] }
+  let(:manual) { double(:manual, version_number: 3) }
+
+  subject {
+    PublishManualService.new(
+      manual_id: manual_id,
+      manual_repository: manual_repository,
+      listeners: listeners,
+      version_number: version_number,
+    )
+  }
+
+  before do
+    allow(manual_repository).to receive(:fetch) { manual }
+    allow(manual_repository).to receive(:store)
+    allow(manual).to receive(:publish)
+  end
+
+  context "when the version number is up to date" do
+    let(:version_number) { 3 }
+
+    it "publishes the manual" do
+      subject.call
+      expect(manual).to have_received(:publish)
+    end
+  end
+
+  context "when the version numbers differ" do
+    let(:version_number) { 4 }
+
+    it "does not publish the manual" do
+      subject.call
+      expect(manual).to_not have_received(:publish)
+    end
+  end
+end