Decouple OrderCycle#fees_for from LineItem

app/models/order_cycle.rb

@@ -144,33 +144,31 @@ class OrderCycle < ActiveRecord::Base
 
   # -- Fees
   def create_adjustments_for(line_item)
-    fees_for(line_item).each { |fee| create_adjustment_for_fee line_item, fee[:enterprise_fee], fee[:label], fee[:role] }
+    variant = line_item.variant
+    distributor = line_item.order.distributor
+
+    fees_for(variant, distributor).each { |fee| create_adjustment_for_fee line_item, fee[:enterprise_fee], fee[:label], fee[:role] }
   end
 
 
-
-
   private
 
   # -- Fees
-  def fees_for(line_item)
+  def fees_for(variant, distributor)
     fees = []
 
-    # If there are multiple distributors with this variant, won't this mean that we get a fee charged for each of them?
-    # We just want the one matching line_item.order.distributor
-
-    exchanges_carrying(line_item).each do |exchange|
+    exchanges_carrying(variant, distributor).each do |exchange|
       exchange.enterprise_fees.each do |enterprise_fee|
         role = exchange.incoming? ? 'supplier' : 'distributor'
         fees << {enterprise_fee: enterprise_fee,
-                 label: adjustment_label_for(line_item, enterprise_fee, role),
+                 label: adjustment_label_for(variant, enterprise_fee, role),
                  role: role}
       end
     end
 
     coordinator_fees.each do |enterprise_fee|
       fees << {enterprise_fee: enterprise_fee,
-               label: adjustment_label_for(line_item, enterprise_fee, 'coordinator'),
+               label: adjustment_label_for(variant, enterprise_fee, 'coordinator'),
                role: 'coordinator'}
     end
 
@@ -182,14 +180,11 @@ class OrderCycle < ActiveRecord::Base
     AdjustmentMetadata.create! adjustment: a, enterprise: enterprise_fee.enterprise, fee_name: enterprise_fee.name, fee_type: enterprise_fee.fee_type, enterprise_role: role
   end
 
-  def adjustment_label_for(line_item, enterprise_fee, role)
-    "#{line_item.variant.product.name} - #{enterprise_fee.fee_type} fee by #{role} #{enterprise_fee.enterprise.name}"
+  def adjustment_label_for(variant, enterprise_fee, role)
+    "#{variant.product.name} - #{enterprise_fee.fee_type} fee by #{role} #{enterprise_fee.enterprise.name}"
   end
 
-  def exchanges_carrying(line_item)
-    coordinator = line_item.order.order_cycle.coordinator
-    distributor = line_item.order.distributor
-
-    exchanges.to_enterprises([coordinator, distributor]).with_variant(line_item.variant)
+  def exchanges_carrying(variant, distributor)
+    exchanges.to_enterprises([coordinator, distributor]).with_variant(variant)
   end
 end

spec/models/order_cycle_spec.rb

@@ -311,17 +311,21 @@ describe OrderCycle do
 
   describe "creating adjustments for a line item" do
     let(:oc) { OrderCycle.new }
-    let(:line_item) { double(:line_item, variant: 123) }
+    let(:variant) { double(:variant) }
+    let(:distributor) { double(:distributor) }
+    let(:order) { double(:order, distributor: distributor) }
+    let(:line_item) { double(:line_item, variant: variant, order: order) }
 
     it "creates adjustment for each fee" do
       fee = {enterprise_fee: 'ef', label: 'label', role: 'role'}
-      oc.stub(:fees_for) { [fee] }
+      oc.should_receive(:fees_for).with(variant, distributor) { [fee] }
       oc.should_receive(:create_adjustment_for_fee).with(line_item, 'ef', 'label', 'role')
 
       oc.send(:create_adjustments_for, line_item)
     end
 
     it "finds fees for a line item" do
+      distributor = double(:distributor)
       ef1 = double(:enterprise_fee)
       ef2 = double(:enterprise_fee)
       ef3 = double(:enterprise_fee)
@@ -331,7 +335,7 @@ describe OrderCycle do
       oc.stub(:coordinator_fees) { [ef3] }
       oc.stub(:adjustment_label_for) { 'label' }
 
-      oc.send(:fees_for, line_item).should ==
+      oc.send(:fees_for, line_item.variant, distributor).should ==
         [{enterprise_fee: ef1, label: 'label', role: 'supplier'},
          {enterprise_fee: ef2, label: 'label', role: 'distributor'},
          {enterprise_fee: ef3, label: 'label', role: 'coordinator'}]
@@ -358,10 +362,10 @@ describe OrderCycle do
     end
 
     it "makes adjustment labels" do
-      line_item = double(:line_item, variant: double(:variant, product: double(:product, name: 'Bananas')))
+      variant = double(:variant, product: double(:product, name: 'Bananas'))
       enterprise_fee = double(:enterprise_fee, fee_type: 'packing', enterprise: double(:enterprise, name: 'Ballantyne'))
 
-      oc.send(:adjustment_label_for, line_item, enterprise_fee, 'distributor').should == "Bananas - packing fee by distributor Ballantyne"
+      oc.send(:adjustment_label_for, variant, enterprise_fee, 'distributor').should == "Bananas - packing fee by distributor Ballantyne"
     end
   end