Perform refresh of products cache on product change

lib/open_food_network/products_cache.rb

@@ -4,14 +4,14 @@ module OpenFoodNetwork
   # the products cache.
   class ProductsCache
     def self.variant_changed(variant)
-      exchanges_featuring_variant(variant).each do |exchange|
+      exchanges_featuring_variants(variant).each do |exchange|
         refresh_cache exchange.receiver, exchange.order_cycle
       end
     end
 
 
     def self.variant_destroyed(variant, &block)
-      exchanges = exchanges_featuring_variant(variant).to_a
+      exchanges = exchanges_featuring_variants(variant).to_a
 
       block.call
 
@@ -22,15 +22,18 @@ module OpenFoodNetwork
 
 
     def self.product_changed(product)
+      exchanges_featuring_variants(product.variants).each do |exchange|
+        refresh_cache exchange.receiver, exchange.order_cycle
+      end
     end
 
 
     private
 
-    def self.exchanges_featuring_variant(variant)
+    def self.exchanges_featuring_variants(variants)
       Exchange.
         outgoing.
-        with_variant(variant).
+        with_any_variant(variants).
         joins(:order_cycle).
         merge(OrderCycle.dated).
         merge(OrderCycle.not_closed)

spec/lib/open_food_network/products_cache_spec.rb

@@ -70,6 +70,25 @@ module OpenFoodNetwork
       end
     end
 
+    describe "when a product changes" do
+      let(:product) { create(:simple_product) }
+      let(:v1) { create(:variant, product: product) }
+      let(:v2) { create(:variant, product: product) }
+      let(:d1) { create(:distributor_enterprise) }
+      let(:d2) { create(:distributor_enterprise) }
+      let(:oc) { create(:open_order_cycle) }
+      let!(:ex1) { create(:exchange, order_cycle: oc, sender: oc.coordinator, receiver: d1, variants: [v1]) }
+      let!(:ex2) { create(:exchange, order_cycle: oc, sender: oc.coordinator, receiver: d2, variants: [v1, v2]) }
+
+      before { product.reload }
+
+      it "refreshes the distribution each variant appears in, once each" do
+        expect(ProductsCache).to receive(:refresh_cache).with(d1, oc).once
+        expect(ProductsCache).to receive(:refresh_cache).with(d2, oc).once
+        ProductsCache.product_changed product
+      end
+    end
+
     describe "refreshing the cache" do
       let(:distributor) { double(:distributor, id: 123) }
       let(:order_cycle) { double(:order_cycle, id: 456) }