[PLATFORM-2311] Add "position" to product data (#76)

* Track field position

* Release commit

Author: CarlosMecha

HISTORY.md

@@ -1,3 +1,8 @@
+2.14.0 / 2018-03-28
+=================
+
+* Support position property as part of product data.
+
 2.13.0 / 2018-02-26
 =================
 

lib/index.js

@@ -1030,6 +1030,12 @@ function enhancedEcommerceTrackProduct(track, trackerName, opts) {
     currency: track.currency()
   };
 
+  // https://developers.google.com/analytics/devguides/collection/analyticsjs/enhanced-ecommerce#product-data
+  // GA requires an integer but our specs says "Number", so it could be a float.
+  if (props.position != null) {
+    product.position = Math.round(props.position);
+  }
+
   // append coupon if it set
   // https://developers.google.com/analytics/devguides/collection/analyticsjs/enhanced-ecommerce#measuring-transactions
   var coupon = track.proxy('properties.coupon');

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@segment/analytics.js-integration-google-analytics",
   "description": "The Google Analytics analytics.js integration.",
-  "version": "2.13.0",
+  "version": "2.14.0",
   "keywords": [
     "analytics.js",
     "analytics.js-integration",

test/index.test.js

@@ -891,7 +891,8 @@ describe('Google Analytics', function() {
             category: 'cat 1',
             sku: 'p-298',
             testDimension: true, 
-            testMetric: true
+            testMetric: true,
+            position: 4
           });
 
           analytics.assert(window.ga.args.length === 5);
@@ -906,7 +907,48 @@ describe('Google Analytics', function() {
             variant: undefined,
             currency: 'CAD',
             metric1: 'true', 
-            dimension1: 'true'
+            dimension1: 'true',
+            position: 4
+          }]);
+          analytics.deepEqual(toArray(window.ga.args[3]), ['ec:setAction', 'add', {}]);
+          analytics.deepEqual(toArray(window.ga.args[4]), ['send', 'event', 'cat 1', 'product added', { 
+            dimension1: 'true',
+            metric1: 'true',
+            nonInteraction: 1 
+          }]);
+        });
+
+        it('should handle float positions for product data', function() {
+          ga.options.setAllMappedProps = false;
+          ga.options.dimensions = { testDimension: 'dimension1' };
+          ga.options.metrics = { testMetric: 'metric1' };
+
+          analytics.track('product added', {
+            currency: 'CAD',
+            quantity: 1,
+            price: 24.75,
+            name: 'my product',
+            category: 'cat 1',
+            sku: 'p-298',
+            testDimension: true, 
+            testMetric: true,
+            position: 4.5
+          });
+          
+          analytics.assert(window.ga.args.length === 5);
+          analytics.deepEqual(toArray(window.ga.args[1]), ['set', '&cu', 'CAD']);
+          analytics.deepEqual(toArray(window.ga.args[2]), ['ec:addProduct', {
+            id: 'p-298',
+            name: 'my product',
+            category: 'cat 1',
+            quantity: 1,
+            price: 24.75,
+            brand: undefined,
+            variant: undefined,
+            currency: 'CAD',
+            metric1: 'true', 
+            dimension1: 'true',
+            position: 5
           }]);
           analytics.deepEqual(toArray(window.ga.args[3]), ['ec:setAction', 'add', {}]);
           analytics.deepEqual(toArray(window.ga.args[4]), ['send', 'event', 'cat 1', 'product added', {