Google Publisher Tags normally participates in placing ads and other content, and our shim does not currently handle this use-case. We can avoid site breakage and add placeholders for content if the shim mimics this capability, as well as stubbing out the API more completely. This will enable fixes for quite a few sites. This will also allow us to make shims for other Google and third-party trackers which rely on or interact with Publisher Tags.

• expand the API surface that is stubbed out more completely to account for sites relying on deprecated or more obscure functionality.
• have the shim perform basic content placement as some sites expect GPT to do.

https://hg.mozilla.org/mozilla-central/rev/79ac5a63d90f

The function removeEventListener of pubads is missing and throwing error. Can we also shim that function. Thanks.

@mortyccp, definitely. I will file a new bug for that ASAP. Do you have a link you can share where it is failing? I'd like to make sure my fix works well on an actual page, as sometimes the obvious fix isn't enough.

Sorry, the website that is failing is my internal web application. I can share the code that's causing the error. It's just very straightforward usage.

  useEffect(() => {
    const listener = event => { ... };

    googletag.cmd.push(() => {
      googletag.pubads().addEventListener("slotRenderEnded", listener);
    });

    return () => {
      googletag.cmd.push(() => {
        googletag.pubads().removeEventListener("slotRenderEnded", listener);
      });
    };
  }, []);