Refresh cache when inventory setting product_selection_from_inventory_only is changed

app/models/spree/preference_decorator.rb

@@ -0,0 +1,31 @@
+require 'open_food_network/products_cache'
+
+module Spree
+  Preference.class_eval do
+    after_save :refresh_products_cache
+
+    # When the setting preferred_product_selection_from_inventory_only has changed, we want to
+    # refresh all active exchanges for this enterprise.
+    def refresh_products_cache
+      if product_selection_from_inventory_only_changed?
+        OpenFoodNetwork::ProductsCache.distributor_changed(enterprise)
+      end
+    end
+
+
+    private
+
+    def product_selection_from_inventory_only_changed?
+      key =~ product_selection_from_inventory_only_regex
+    end
+
+    def enterprise
+      enterprise_id = key.match(product_selection_from_inventory_only_regex)[1]
+      enterprise = Enterprise.find enterprise_id
+    end
+
+    def product_selection_from_inventory_only_regex
+      /^enterprise\/product_selection_from_inventory_only\/(\d+)$/
+    end
+  end
+end

lib/open_food_network/products_cache.rb

@@ -88,6 +88,13 @@ module OpenFoodNetwork
     end
 
 
+    def self.distributor_changed(enterprise)
+      Exchange.cachable.where(receiver_id: enterprise).each do |exchange|
+        refresh_cache exchange.receiver, exchange.order_cycle
+      end
+    end
+
+
     private
 
     def self.exchanges_featuring_variants(variants, distributor: nil)

spec/features/admin/enterprises_spec.rb

@@ -251,6 +251,32 @@ feature %q{
   end
 
 
+  describe "inventory settings", js: true do
+    let!(:enterprise) { create(:distributor_enterprise) }
+    let!(:product) { create(:simple_product) }
+    let!(:order_cycle) { create(:simple_order_cycle, distributors: [enterprise], variants: [product.variants.first]) }
+
+    before do
+      Delayed::Job.destroy_all
+      quick_login_as_admin
+    end
+
+    it "refreshes the cache when I change what products appear on my shopfront" do
+      # Given a product that's not in my inventory, but is in an active order cycle
+
+      # When I change which products appear on the shopfront
+      visit edit_admin_enterprise_path(enterprise)
+      within(".side_menu") { click_link 'Inventory Settings' }
+      choose 'enterprise_preferred_product_selection_from_inventory_only_1'
+
+      # Then a job should have been enqueued to refresh the cache
+      expect do
+        click_button 'Update'
+      end.to enqueue_job RefreshProductsCacheJob, distributor_id: enterprise.id, order_cycle_id: order_cycle.id
+    end
+  end
+
+
   context "as an Enterprise user", js: true do
     let(:supplier1) { create(:supplier_enterprise, name: 'First Supplier') }
     let(:supplier2) { create(:supplier_enterprise, name: 'Another Supplier') }

spec/lib/open_food_network/products_cache_spec.rb

@@ -376,6 +376,16 @@ module OpenFoodNetwork
       end
     end
 
+    describe "when a distributor enterprise is changed" do
+      let(:d) { create(:distributor_enterprise) }
+      let(:oc) { create(:open_order_cycle, distributors: [d]) }
+
+      it "updates each distribution the enterprise is active in" do
+        expect(ProductsCache).to receive(:refresh_cache).with(d, oc)
+        ProductsCache.distributor_changed d
+      end
+    end
+
     describe "refreshing the cache" do
       let(:distributor) { double(:distributor) }
       let(:order_cycle) { double(:order_cycle) }

spec/models/spree/preference_spec.rb

@@ -0,0 +1,23 @@
+require 'spec_helper'
+
+module Spree
+  describe Preference do
+    describe "refreshing the products cache" do
+      it "reports when product_selection_from_inventory_only has changed" do
+        p = Preference.new(key: 'enterprise/product_selection_from_inventory_only/123')
+        expect(p.send(:product_selection_from_inventory_only_changed?)).to be_true
+      end
+
+      it "reports when product_selection_from_inventory_only has not changed" do
+        p = Preference.new(key: 'enterprise/shopfront_message/123')
+        expect(p.send(:product_selection_from_inventory_only_changed?)).to be_false
+      end
+
+      it "looks up the referenced enterprise" do
+        e = create(:distributor_enterprise)
+        p = Preference.new(key: "enterprise/product_selection_from_inventory_only/#{e.id}")
+        expect(p.send(:enterprise)).to eql e
+      end
+    end
+  end
+end