Replace proxies with modules

app/serializers/api/product_serializer.rb

@@ -1,4 +1,4 @@
-require 'open_food_network/variant_proxy'
+require 'open_food_network/scope_variant_to_hub'
 
 class Api::ProductSerializer < ActiveModel::Serializer
   # TODO
@@ -43,9 +43,13 @@ class Api::CachedProductSerializer < ActiveModel::Serializer
   has_one :master, serializer: Api::VariantSerializer
 
   def variants
+    # We use the in_stock? method here instead of the in_stock scope because we need to
+    # look up the stock as overridden by VariantOverrides, and the scope method is not affected
+    # by them.
+
     object.variants.
       for_distribution(options[:current_order_cycle], options[:current_distributor]).
-      in_stock.
-      map { |v| OpenFoodNetwork::VariantProxy.new(v, options[:current_distributor]) }
+      each { |v| v.scope_to_hub options[:current_distributor] }.
+      select(&:in_stock?)
   end
 end

lib/open_food_network/product_proxy.rb

@@ -1,23 +0,0 @@
-require 'open_food_network/variant_proxy'
-
-module OpenFoodNetwork
-  # Variants can have several fields overridden on a per-enterprise basis by the
-  # VariantOverride model. These overrides can be applied to variants by wrapping their
-  # products in this proxy, which wraps the product's variants in VariantProxy.
-  class ProductProxy
-    instance_methods.each { |m| undef_method m unless m =~ /(^__|^send$|^object_id$)/ }
-
-    def initialize(product, hub)
-      @product = product
-      @hub = hub
-    end
-
-    def variants
-      @product.variants.map { |v| VariantProxy.new(v, @hub) }
-    end
-
-    def method_missing(name, *args, &block)
-      @product.send(name, *args, &block)
-    end
-  end
-end

lib/open_food_network/scope_variant_to_hub.rb

@@ -0,0 +1,18 @@
+module OpenFoodNetwork
+  module ScopeVariantToHub
+    def price
+      VariantOverride.price_for(@hub, self) || super
+    end
+
+    def count_on_hand
+      VariantOverride.count_on_hand_for(@hub, self) || super
+    end
+  end
+end
+
+Spree::Variant.class_eval do
+  def scope_to_hub(hub)
+    extend OpenFoodNetwork::ScopeVariantToHub
+    @hub = hub
+  end
+end

lib/open_food_network/variant_proxy.rb

@@ -1,27 +0,0 @@
-module OpenFoodNetwork
-  # Variants can have several fields overridden on a per-enterprise basis by the
-  # VariantOverride model. These overrides can be applied to variants by wrapping in an
-  # instance of the VariantProxy class. This class proxies most methods back to the wrapped
-  # variant, but checks for overrides when fetching some properties.
-  class VariantProxy
-    instance_methods.each { |m| undef_method m unless m =~ /(^__|^send$|^object_id$)/ }
-
-    def initialize(variant, hub)
-      @variant = variant
-      @hub = hub
-    end
-
-    def price
-      VariantOverride.price_for(@hub, @variant) || @variant.price
-    end
-
-    def price_with_fees(distributor, order_cycle)
-      price + @variant.fees_for(distributor, order_cycle)
-    end
-
-
-    def method_missing(name, *args, &block)
-      @variant.send(name, *args, &block)
-    end
-  end
-end

spec/lib/open_food_network/product_proxy_spec.rb

@@ -1,27 +0,0 @@
-require 'open_food_network/product_proxy'
-require 'open_food_network/variant_proxy'
-
-module OpenFoodNetwork
-  describe ProductProxy do
-    let(:hub) { double(:hub) }
-    let(:p)   { double(:product, name: 'name') }
-    let(:pp) { ProductProxy.new(p, hub) }
-
-    describe "delegating calls to proxied product" do
-      it "delegates name" do
-        pp.name.should == 'name'
-      end
-    end
-
-    describe "fetching the variants" do
-      let(:v1) { double(:variant) }
-      let(:v2) { double(:variant) }
-      let(:p) { double(:product, variants: [v1, v2]) }
-
-      it "returns variants wrapped in VariantProxy" do
-        # #class is proxied too, so we test that it worked by #object_id
-        pp.variants.map(&:object_id).sort.should_not == [v1.object_id, v2.object_id].sort
-      end
-    end
-  end
-end

spec/lib/open_food_network/scope_variant_to_hub_spec.rb

@@ -0,0 +1,35 @@
+require 'open_food_network/scope_variant_to_hub'
+
+module OpenFoodNetwork
+  describe ScopeVariantToHub do
+    let(:hub) { create(:distributor_enterprise) }
+    let(:v)   { create(:variant, price: 11.11, count_on_hand: 1) }
+    let(:vo)  { create(:variant_override, hub: hub, variant: v, price: 22.22, count_on_hand: 2) }
+
+    describe "overriding price" do
+      it "returns the overridden price when one is present" do
+        vo
+        v.scope_to_hub hub
+        v.price.should == 22.22
+      end
+
+      it "returns the variant's price otherwise" do
+        v.scope_to_hub hub
+        v.price.should == 11.11
+      end
+    end
+
+    describe "overriding stock levels" do
+      it "returns the overridden stock level when one is present" do
+        vo
+        v.scope_to_hub hub
+        v.count_on_hand.should == 2
+      end
+
+      it "returns the variant's stock level otherwise" do
+        v.scope_to_hub hub
+        v.count_on_hand.should == 1
+      end
+    end
+  end
+end

spec/lib/open_food_network/variant_proxy_spec.rb

@@ -1,27 +0,0 @@
-require 'open_food_network/variant_proxy'
-
-module OpenFoodNetwork
-  describe VariantProxy do
-    let(:hub) { double(:hub) }
-    let(:v)   { double(:variant, sku: 'sku123', price: 'global price') }
-    let(:vp) { VariantProxy.new(v, hub) }
-
-    describe "delegating calls to proxied variant" do
-      it "delegates sku" do
-        vp.sku.should == 'sku123'
-      end
-    end
-
-    describe "looking up the price" do
-      it "returns the override price when there is one" do
-        VariantOverride.stub(:price_for) { 'override price' }
-        vp.price.should == 'override price'
-      end
-
-      it "returns the global price otherwise" do
-        VariantOverride.stub(:price_for) { nil }
-        vp.price.should == 'global price'
-      end
-    end
-  end
-end