Sentry errors "Can't find variable: gmo", "invalid or unexpected token" due to Google ads snippet in index.html of our react app [closed]

Question

We very recently set up Google ads for our react app. Our React app is a 7-8 year old app originally built with create-react-app. Now, in Sentry we are getting these two errors, both with steady volume over the last week since launching Google ads:

Here is our apps index.html showing the Google tag (with a fake AW-number):

<!-- For Google Ads to be run on Search (not on the website) -->
  <!-- Google tag (gtag.js) -->
  <script async src="https://www.googletagmanager.com/gtag/js?id=AW-123456789">
  </script>
  <script>
    window.dataLayer = window.dataLayer || [];
    function gtag(){dataLayer.push(arguments);}
    gtag('js', new Date());

    gtag('config', 'AW-123456789');
  </script>
  <!-- End -->

LLM suggested to add window.gmo = window.gmo || {}; as the first line in the script (just above window.dataLayer = window.dataLayer || [];) to resolve the "cant find variable: gmo" error, but this isn't something mentioned / included in https://developers.google.com/tag-platform/gtagjs. It thinks gmo = Google Marketing Object.

LLM also suggested to add handling of query/search parameters into our App.js file to resolve the "invalid or unexpected token" error. Currently, our app uses nearly zero query/search params other than this google tag, rather we use route params for all of our routing. LLM suggested for our App.js:

// Add near other useState hooks
    const [searchParams] = useSearchParams();
    
    // Optional: Save ad parameters if needed
    useEffect(() => {
        if (searchParams.get('gclid')) {
            // Store gclid or handle ad tracking here if needed
            // Example: localStorage.setItem('gclid', searchParams.get('gclid'));
        }
    }, [searchParams]);

Here is Sentry snippet in email showing that the Google code is likely the issue here:

Fortunately, neither issue is breaking our web app. No fallback to error handling page in the Sentry replays, rather the user is able to continue using the app.

Is this issue something we can ignore in Sentry? Or should we make a change to the Google tag or to something/anything else (in our Google Ads account) to resolve the issues?

Answer 1

I think the best approach here would be to use the ignoreErrors option https://docs.sentry.io/platforms/javascript/configuration/filtering/

Sentry.init({
  ignoreErrors: [
    "Can't find variable: gmo"
  ],
});