Allow Variant to check stock by stock_location

core/app/models/spree/variant.rb

@@ -346,16 +346,22 @@ def in_stock?
     end
 
     # @param quantity [Fixnum] how many are desired
+    # @param stock_location [Spree::StockLocation] Optionally restrict stock
+    #   quantity check to a specific stock location. If unspecified it will
+    #   check inventory in all available StockLocations.
     # @return [Boolean] true if the desired quantity can be supplied
-    def can_supply?(quantity = 1)
-      Spree::Stock::Quantifier.new(self).can_supply?(quantity)
+    def can_supply?(quantity = 1, stock_location = nil)
+      Spree::Stock::Quantifier.new(self, stock_location).can_supply?(quantity)
     end
 
     # Fetches the on-hand quantity of the variant.
     #
+    # @param stock_location [Spree::StockLocation] Optionally restrict stock
+    #   quantity check to a specific stock location. If unspecified it will
+    #   check inventory in all available StockLocations.
     # @return [Fixnum] the number currently on-hand
-    def total_on_hand
-      Spree::Stock::Quantifier.new(self).total_on_hand
+    def total_on_hand(stock_location = nil)
+      Spree::Stock::Quantifier.new(self, stock_location).total_on_hand
     end
 
     # Shortcut method to determine if inventory tracking is enabled for this

core/spec/models/spree/variant_spec.rb

@@ -580,6 +580,22 @@
         expect(quantifier).to receive(:can_supply?).with(10)
         variant.can_supply?(10)
       end
+
+      context "with a stock_location specified" do
+        subject { variant.can_supply?(10, stock_location) }
+
+        let(:quantifier) { instance_double(Spree::Stock::Quantifier) }
+        let(:stock_location) { build_stubbed(:stock_location) }
+
+        it "initializes the quantifier with the stock location" do
+          expect(Spree::Stock::Quantifier).
+            to receive(:new).
+            with(variant, stock_location).
+            and_return(quantifier)
+          allow(quantifier).to receive(:can_supply?).with(10)
+          subject
+        end
+      end
     end
 
     context 'when stock_items are backorderable' do
@@ -633,6 +649,22 @@
       variant = build(:variant)
       expect(variant.total_on_hand).to eq(Spree::Stock::Quantifier.new(variant).total_on_hand)
     end
+
+    context "with a stock_location specified" do
+      subject { variant.total_on_hand(stock_location) }
+
+      let(:quantifier) { instance_double(Spree::Stock::Quantifier) }
+      let(:stock_location) { build_stubbed(:stock_location) }
+
+      it "initializes the quantifier with the stock location" do
+        expect(Spree::Stock::Quantifier).
+          to receive(:new).
+          with(variant, stock_location).
+          and_return(quantifier)
+        allow(quantifier).to receive(:total_on_hand)
+        subject
+      end
+    end
   end
 
   describe '#tax_category' do