Replace 'supported_sites' scalar with 'visit_supported_site' event

Event telemetry is easier from the analysis perspective to answer questions around frequency of visits.

docs/METRICS.md

@@ -82,15 +82,13 @@ While some of these questions may be partially answerable by this extension, ans
 
 ## Sample Pings
 
-We will be sending pings using [Scalar](https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/collection/scalars.html) and [Event Telemetry](https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/collection/events.html) via the [WebExtensions Telemetry API](https://bugzilla.mozilla.org/show_bug.cgi?id=1280234).
-
-Each scalar will exist as part of the `main` ping under `payload.processes.dynamic.scalars` as a key-value pair in the `scalars` object. The data types for values are one of the scalar types (number, string or boolean).
+We will be sending pings using [Event Telemetry](https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/collection/events.html) via the [WebExtensions Telemetry API](https://bugzilla.mozilla.org/show_bug.cgi?id=1280234).
 
 Each event will exist as part of the `main` ping under `payload.processes.dynamic.events` as an array in the `events` array. The data types of individual fields for each event follow the Event Telemetry [serialization format](https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/collection/events.html#serialization-format).
 
-The telemetry category for both scalars and events is `'extension.pricealerts'`. Note: Scalar telemetry category names [do not allow underscores](https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/collection/scalars.html#scalar-limitations).
+The telemetry category for events is `'extension.price_alerts'`.
 
-Below is a sample ping for the `supported_sites` scalar and `badge_toolbar_button` event.
+Below is a sample ping for the `badge_toolbar_button` and `visit_supported_site` events.
 
 ```javascript
 {
@@ -101,13 +99,11 @@ Below is a sample ping for the `supported_sites` scalar and `badge_toolbar_butto
     "processes": {
       // ...
       "dynamic": {
-        "scalars": {
-          "extension.pricealerts.supported_sites": 5
-        },
+        // ...
         "events": [
           [
-            1634,
-            "extension.pricealerts",
+            2079,
+            "extension.price_alerts",
             "badge_toolbar_button",
             "toolbar_button",
             null,
@@ -115,6 +111,16 @@ Below is a sample ping for the `supported_sites` scalar and `badge_toolbar_butto
               "badge_type": "add",
               "tracked_prods": "5"
             }
+          ],
+          [
+            2081,
+            "extension.price_alerts",
+            "visit_supported_site",
+            "supported_site",
+            null,
+            {
+              "tracked_prods": "5"
+            }
           ]
         ]
       }
@@ -154,17 +160,19 @@ Below is a sample ping for the `supported_sites` scalar and `badge_toolbar_butto
   - `'walmart_link'`: Sends the user to Walmart.
 
 
-## Collection (Scalars)
+## Collection (User Events)
 
-### `supported_sites`
+### `visit_supported_site`
 
-Increments when the user navigates to a Supported Site.
+Fired when the user navigates to a Supported Site.
 
 #### Payload properties
-Note: The key below is the scalar name prepended with the telemetry category, separated by a `'.'`.
-- `'extension.pricealerts.supported_sites'`: Number; the current count for the number of times the user has visited a Supported Site during the session.
-
-## Collection (User Events)
+- `methods`: String
+  - `'visit_supported_site'`
+- `objects`: String
+  - `'supported_site'`
+- `extra_keys`: Object
+  - `'tracked_prods'`
 
 ### `open_popup`
 

src/background/index.js

@@ -18,10 +18,10 @@ import {handleWebRequest, updatePrices} from 'commerce/background/price_updates'
 import store from 'commerce/state';
 import {checkMigrations} from 'commerce/state/migrations';
 import {loadStateFromStorage} from 'commerce/state/sync';
-import {registerProbes} from 'commerce/background/telemetry';
+import {registerEvents} from 'commerce/background/telemetry';
 
 (async function main() {
-  registerProbes();
+  registerEvents();
 
   // Set browser action default badge color, which can't be set via manifest
   browser.browserAction.setBadgeBackgroundColor({

src/background/telemetry.js

@@ -3,23 +3,21 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * Registers and records telemetry scalars and events throughout the extension.
+ * Registers and records telemetry events throughout the extension.
  * @module
  */
 
-// Scalar category names can't have underscores
-const CATEGORY = 'extension.pricealerts';
-
-const SCALARS = {
-  // Incremented when the user navigates to a supported site (e.g. Amazon)
-  supported_sites: {
-    kind: 'count',
-    record_on_release: true,
-  },
-};
+const CATEGORY = 'extension.price_alerts';
 
 const EVENTS = {
   // User Events
+  // User visits a supported site
+  visit_supported_site: {
+    methods: ['visit_supported_site'],
+    objects: ['supported_site'],
+    extra_keys: ['tracked_prods'],
+  },
+
   // User clicks toolbar button to open the popup
   open_popup: {
     methods: ['open_popup'],
@@ -153,8 +151,7 @@ const EVENTS = {
   },
 };
 
-export async function registerProbes() {
-  await browser.telemetry.registerScalars(CATEGORY, SCALARS);
+export async function registerEvents() {
   await browser.telemetry.registerEvents(CATEGORY, EVENTS);
 }
 
@@ -170,13 +167,3 @@ export async function recordEvent(method, object, value, extra) {
     extra,
   );
 }
-
-export async function scalarAdd(scalarName, value) {
-  if (!browser.telemetry.canUpload()) {
-    return;
-  }
-  await browser.telemetry.scalarAdd(
-    `${CATEGORY}.${scalarName}`,
-    value,
-  );
-}