Notify when stock limit reached on shopfront rather than silently capping

app/assets/javascripts/darkswarm/directives/on_hand.js.coffee

@@ -0,0 +1,9 @@
+Darkswarm.directive "ofnOnHand", ->
+  restrict: 'A'
+  link: (scope, elem, attr) ->
+    on_hand = parseInt(attr.ofnOnHand)
+    elem.bind 'change', (e) ->
+      if parseInt(elem.val()) > on_hand
+        scope.$apply ->
+          alert t('insufficient_stock', {on_hand: on_hand})
+          elem.val(on_hand)

app/assets/javascripts/templates/partials/shop_variant_no_group_buy.html.haml

@@ -7,6 +7,6 @@
   placeholder: "0",
   "ofn-disable-scroll" => true,
   "ng-model" => "variant.line_item.quantity",
-  max: "{{variant.on_demand && 9999 || variant.count_on_hand }}",
+  "ofn-on-hand" => "{{variant.on_demand && 9999 || variant.count_on_hand }}",
   "ng-disabled" => "!variant.on_demand && variant.count_on_hand == 0",
   name: "variants[{{variant.id}}]", id: "variants_{{variant.id}}"}

app/assets/javascripts/templates/partials/shop_variant_with_group_buy.html.haml

@@ -8,7 +8,7 @@
       "ng-model" => "variant.line_item.quantity",
       placeholder: "{{'shop_variant_quantity_min' | t}}",
       "ofn-disable-scroll" => true,
-      max: "{{variant.on_demand && 9999 || variant.count_on_hand }}",
+      "ofn-on-hand" => "{{variant.on_demand && 9999 || variant.count_on_hand }}",
       name: "variants[{{variant.id}}]", id: "variants_{{variant.id}}"}
     %span.bulk-input
       %input.bulk.second{type: :number,

spec/features/consumer/shopping/shopping_spec.rb

@@ -238,6 +238,17 @@ feature "As a consumer I want to shop with a distributor", js: true do
         Spree::LineItem.where(id: li).should be_empty
       end
 
+      it "alerts us when we enter a quantity greater than the stock available" do
+        variant.update_attributes on_hand: 5
+        visit shop_path
+
+        accept_alert 'Insufficient stock available, only 5 remaining' do
+          fill_in "variants[#{variant.id}]", with: '10'
+        end
+
+        page.should have_field "variants[#{variant.id}]", with: '5'
+      end
+
       describe "when a product goes out of stock just before it's added to the cart" do
         it "stops the attempt, shows an error message and refreshes the products asynchronously" do
           variant.update_attributes! on_hand: 0