Refresh products cache when price is changed or destroyed

app/models/spree/price_decorator.rb

@@ -0,0 +1,13 @@
+module Spree
+  Price.class_eval do
+    after_save :refresh_products_cache
+    after_destroy :refresh_products_cache
+
+
+    private
+
+    def refresh_products_cache
+      variant.refresh_products_cache
+    end
+  end
+end

app/models/spree/variant_decorator.rb

@@ -85,12 +85,6 @@ Spree::Variant.class_eval do
     end
   end
 
-  private
-
-  def update_weight_from_unit_value
-    self.weight = weight_from_unit_value if self.product.variant_unit == 'weight' && unit_value.present?
-  end
-
   def refresh_products_cache
     if is_master?
       product.refresh_products_cache
@@ -99,6 +93,13 @@ Spree::Variant.class_eval do
     end
   end
 
+
+  private
+
+  def update_weight_from_unit_value
+    self.weight = weight_from_unit_value if self.product.variant_unit == 'weight' && unit_value.present?
+  end
+
   def destruction
     if is_master?
       exchange_variants(:reload).destroy_all

spec/models/spree/price_spec.rb

@@ -0,0 +1,21 @@
+require 'spec_helper'
+
+module Spree
+  describe Price do
+    describe "callbacks" do
+      let(:variant) { create(:variant) }
+      let(:price) { variant.default_price }
+
+      it "refreshes the products cache on change" do
+        expect(OpenFoodNetwork::ProductsCache).to receive(:variant_changed).with(variant)
+        price.amount = 123
+        price.save
+      end
+
+      it "refreshes the products cache on destroy" do
+        expect(OpenFoodNetwork::ProductsCache).to receive(:variant_changed).with(variant)
+        price.destroy
+      end
+    end
+  end
+end