From d19f4ca5dcc511fb5169f4f049a7b9b63d2706c7 Mon Sep 17 00:00:00 2001
From: gpolaert <gpolaert@pubstack.io>
Date: Mon, 2 Nov 2020 20:39:38 +0100
Subject: [PATCH] feat: add the elapsed time to events for debugging (#5868)

* feat: add the elapsed time to events for debugging

* naming
---
 src/events.js | 3 ++-
 src/utils.js  | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/events.js b/src/events.js
index e7a11635476..8749ddf206b 100644
--- a/src/events.js
+++ b/src/events.js
@@ -44,7 +44,8 @@ module.exports = (function () {
     eventsFired.push({
       eventType: eventString,
       args: eventPayload,
-      id: key
+      id: key,
+      elapsedTime: utils.getPerformanceNow(),
     });
 
     /** Push each specific callback to the `callbacks` array.
diff --git a/src/utils.js b/src/utils.js
index 8af7a25668d..acdf0f101ad 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -727,6 +727,14 @@ export function timestamp() {
   return new Date().getTime();
 }
 
+/**
+ * The returned value represents the time elapsed since the time origin. @see https://developer.mozilla.org/en-US/docs/Web/API/Performance/now
+ * @returns {number}
+ */
+export function getPerformanceNow() {
+  return (window.performance && window.performance.now && window.performance.now()) || 0;
+}
+
 /**
  * When the deviceAccess flag config option is false, no cookies should be read or set
  * @returns {boolean}