Add ProductProxy which wraps the product's variants in VariantProxys

lib/open_food_network/product_proxy.rb

@@ -0,0 +1,18 @@
+module OpenFoodNetwork
+  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

spec/lib/open_food_network/product_proxy_spec.rb

@@ -0,0 +1,27 @@
+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