Merge pull request #1980 from mozilla/hotfix_1978_kpi_off

Fix exception being thrown if KPI data is disabled.

resources/static/common/js/modules/interaction_data.js

@@ -220,9 +220,12 @@ BrowserID.Modules.InteractionData = (function() {
   }
 
   function onKPIData(msg, result) {
+    // currentData will be undefined if sampling is disabled.
     var currentData = this.getCurrent();
-    _.extend(currentData, result);
-    model.setCurrent(currentData);
+    if (currentData) {
+      _.extend(currentData, result);
+      model.setCurrent(currentData);
+    }
   }
 
   // At every load, after session_context returns, try to publish the previous
@@ -346,6 +349,14 @@ BrowserID.Modules.InteractionData = (function() {
     ,
     setNameTable: function(table) {
       this.mediatorToKPINameTable = table;
+    },
+
+    enable: function() {
+      this.samplingEnabled = true;
+    },
+
+    disable: function() {
+      this.samplingEnabled = false;
     }
     // END TEST API
   });

resources/static/test/cases/common/js/modules/interaction_data.js

@@ -15,7 +15,7 @@
       mediator = bid.Mediator,
       controller;
 
-  module("shared/modules/interaction_data", {
+  module("common/js/modules/interaction_data", {
     setup: function() {
       testHelpers.setup();
       localStorage.removeItem("interaction_data");
@@ -249,13 +249,23 @@
     });
   });
 
-  asyncTest("kpi_data message adds fields to current kpi_data", function() {
+  asyncTest("kpi_data message only adds fields to current kpi_data if sampling is enabled", function() {
     createController();
     network.withContext(function() {
+      // number_emails will not be added to KPI data because sampling is
+      // disabled.
+      controller.disable();
       mediator.publish("kpi_data", { number_emails: 1 });
+      testHelpers.testUndefined(controller.getCurrent());
+
+      // number_emails will be added to KPI data because sampling is
+      // disabled.
+      controller.enable();
+      mediator.publish("kpi_data", { number_emails: 2 });
       testHelpers.testObjectValuesEqual(controller.getCurrent(), {
-        number_emails: 1
+        number_emails: 2
       });
+
       start();
     });
   });