in cases where crypto.randomuuid is unavailable, polyfill with crypto randomvalues (#563)

Author: sol-loup

app/code/Meta/Conversion/view/frontend/web/js/metaPixelTracker.js

@@ -3,10 +3,24 @@ define([
     'jquery'
 ], function ($) {
     'use strict';
+    function generateUUID() {
+        if(crypto.randomUUID) {
+            return crypto.randomUUID();
+        }
+        // crypto.randomUUID() was added to chrome in late 2021. This is a passable polyfill.
+        const buf = new Uint8Array(16);
+        crypto.getRandomValues(buf);
+        buf[6] = (buf[6] & 0x0f) | 0x40; // set version to 0100 (UUID version 4)
+        buf[8] = (buf[8] & 0x3f) | 0x80; // set variant to 10 (RFC4122 variant)
+        return Array.from(buf).map((b, i) => {
+            const s = b.toString(16).padStart(2, '0');
+            return (i === 4 || i === 6 || i === 8 || i === 10) ? '-' + s : s;
+        }).join('');
+    }
 
     return function (config) {
         var browserEventData = config.browserEventData,
-            eventId = crypto.randomUUID();
+            eventId = generateUUID();
 
         config.payload.eventId = eventId;