Add revenue tracking to analytics

app/models/User.coffee

@@ -128,6 +128,7 @@ module.exports = class User extends CocoModel
 
   getGemPromptGroup: ->
     # A/B Testing whether extra prompt when low gems leads to more gem purchases
+    # TODO: Rename gem purchase event in BuyGemsModal to 'Started gem purchase' after this test is over
     return @gemPromptGroup if @gemPromptGroup
     group = me.get('testGroupNumber') % 8
     @gemPromptGroup = switch group

app/views/play/modal/BuyGemsModal.coffee

@@ -57,6 +57,7 @@ module.exports = class BuyGemsModal extends ModalView
       Backbone.Mediator.publish 'buy-gems-modal:purchase-initiated', { productID: productID }
 
     else
+      # TODO: rename this event to 'Started gem purchase' after gemPrompt A/B test is over
       application.tracker?.trackEvent 'Started purchase', { productID: productID }
       stripeHandler.open({
         description: $.t(product.i18n)
@@ -78,6 +79,9 @@ module.exports = class BuyGemsModal extends ModalView
     @render()
     jqxhr = $.post('/db/payment', data)
     jqxhr.done(=>
+      application.tracker?.trackEvent 'Finished gem purchase',
+        productID: @productBeingPurchased.id
+        revenue: @productBeingPurchased.amount / 100
       document.location.reload()
     )
     jqxhr.fail(=>

app/views/play/modal/SubscribeModal.coffee

@@ -72,6 +72,8 @@ module.exports = class SubscribeModal extends ModalView
       amount: 599
     }
 
+    @purchasedAmount = options.amount
+
     stripeHandler.open(options)
 
   onStripeReceivedToken: (e) ->
@@ -88,7 +90,7 @@ module.exports = class SubscribeModal extends ModalView
     me.patch({headers: {'X-Change-Plan': 'true'}})
 
   onSubscriptionSuccess: ->
-    application.tracker?.trackEvent 'Finished subscription purchase', {}
+    application.tracker?.trackEvent 'Finished subscription purchase', revenue: @purchasedAmount / 100
     application.tracker?.trackPageView "subscription/finish-purchase", ['Google Analytics']
     Backbone.Mediator.publish 'subscribe-modal:subscribed', {}
     @playSound 'victory'