Fix: Allow a default_weight of zero

A default weight of zero doesn't throw a divide by zero error anymore.  Added a test condition for it.

Signed-off-by: Nathan Lowrie <nate@finelineautomation.com>

app/models/spree/calculator/active_shipping/base.rb

@@ -141,30 +141,32 @@ def retrieve_timings(origin, destination, packages)
             else
               message = re.message
             end
-            
+
             error = Spree::ShippingError.new("#{I18n.t(:shipping_error)}: #{message}")
             Rails.cache.write @cache_key+"-timings", error #write error to cache to prevent constant re-lookups
             raise error
           end
         end
 
 
-        
+
         private
-        
+
         def convert_order_to_weights_array(order)
           multiplier = Spree::ActiveShipping::Config[:unit_multiplier]
           default_weight = Spree::ActiveShipping::Config[:default_weight]
           max_weight = max_weight_for_country(order.ship_address.country)
-          
+
           weights = order.line_items.map do |line_item|
             item_weight = line_item.variant.weight.to_f
             item_weight = default_weight if item_weight <= 0
             item_weight *= multiplier
-            
+
             quantity = line_item.quantity
             if max_weight <= 0
               item_weight * quantity
+            elsif item_weight == 0
+              0
             else
               if item_weight < max_weight
                 max_quantity = (max_weight/item_weight).floor
@@ -193,7 +195,7 @@ def packages(order)
           packages = []
           weights = convert_order_to_weights_array(order)
           max_weight = max_weight_for_country(order.ship_address.country)
-          
+
           if max_weight <= 0
             packages << Package.new(weights.sum, [], :units => units)
           else
@@ -208,7 +210,7 @@ def packages(order)
             end
             packages << Package.new(package_weight, [], :units => units) if package_weight > 0
           end
-          
+
           packages
         end
 

spec/models/weight_limits_spec.rb

@@ -3,7 +3,7 @@
 
 module ActiveShipping
   describe Spree::Calculator do
-  
+
     let(:country) { mock_model Spree::Country, :iso => "CA", :state_name => "Quebec", :state => nil }
     let(:address) { mock_model Spree::Address, :country => country, :state_name => country.state_name, :city => "Montreal", :zipcode => "H2B", :state => nil }
     let(:usa) { mock_model Spree::Country, :iso => "US", :state => mock_model(Spree::State, :abbr => "MD") }
@@ -18,45 +18,45 @@ module ActiveShipping
     let(:us_order) { mock_model Spree::Order, :number => "R12347", :ship_address => us_address, :line_items =>  [ line_item_1, line_item_2, line_item_3 ] }
     let(:too_heavy_order) { mock_model Spree::Order, :number => "R12349", :ship_address => us_address, :line_items =>  [ line_item_3, line_item_4 ] }
     let(:order_with_invalid_weights) { mock_model Spree::Order, :number => "R12350", :ship_address => us_address, :line_items =>  [ line_item_5, line_item_6 ] }
-    
-    
+
+
     let(:international_calculator) {  Spree::Calculator::Usps::PriorityMailInternational.new }
     let(:domestic_calculator) {  Spree::Calculator::Usps::PriorityMail.new }
-    
+
     before(:each) do
       Rails.cache.clear
       Spree::ActiveShipping::Config.set(:units => "imperial")
       Spree::ActiveShipping::Config.set(:unit_multiplier => 16)
       Spree::ActiveShipping::Config.set(:default_weight => 1)
     end
-    
+
     describe "compute" do
       context "for international calculators" do
         it "should convert order line items to weights array for non-US countries (ex. Canada [limit = 66 lbs])" do
           weights = international_calculator.send :convert_order_to_weights_array, order
           weights.should == [20.0, 21.0, 29.0, 60.0, 60.0, 60.0].map{|x| x*Spree::ActiveShipping::Config[:unit_multiplier]}
         end
-        
+
         it "should create array of packages" do
           packages = international_calculator.send :packages, order
           packages.size.should == 5
           packages.map{|package| package.weight.amount}.should == [41.0, 29.0, 60.0, 60.0, 60.0].map{|x| x*Spree::ActiveShipping::Config[:unit_multiplier]}
           packages.map{|package| package.weight.unit}.uniq.should == [:ounces]
         end
-        
+
         context "raise exception if max weight exceeded" do
           it "should get Spree::ShippingError" do
             expect { international_calculator.compute(too_heavy_order) }.to raise_error(Spree::ShippingError)
           end
         end
       end
-         
+
       context "for domestic calculators" do
         it "should not convert order line items to weights array for US" do
           weights = domestic_calculator.send :convert_order_to_weights_array, us_order
           weights.should == [20.0, 21.0, 29.0, 60.0, 60.0, 60.0].map{|x| x*Spree::ActiveShipping::Config[:unit_multiplier]}
         end
-        
+
         it "should create array with one package for US" do
           packages = domestic_calculator.send :packages, us_order
           packages.size.should == 4
@@ -65,20 +65,28 @@ module ActiveShipping
         end
       end
     end
-    
+
     describe "weight limits" do
       it "should be set for USPS calculators" do
         international_calculator.send(:max_weight_for_country, country).should == 66.0*Spree::ActiveShipping::Config[:unit_multiplier] # Canada
         domestic_calculator.send(:max_weight_for_country, country).should == 70.0*Spree::ActiveShipping::Config[:unit_multiplier]
       end
     end
-    
+
     describe "validation of line item weight" do
       it "should avoid zero weight or negative weight" do
         weights = domestic_calculator.send :convert_order_to_weights_array, order_with_invalid_weights
         default_weight = Spree::ActiveShipping::Config[:default_weight] * Spree::ActiveShipping::Config[:unit_multiplier]
         weights.should == [default_weight, default_weight]
       end
     end
+
+    describe "validation of default weight of zero" do
+      it "should accept zero default weight" do
+        Spree::ActiveShipping::Config.set(:default_weight => 0)
+        weights = domestic_calculator.send :convert_order_to_weights_array, order_with_invalid_weights
+        weights.should == [0, 0]
+      end
+    end
   end
 end