Polyfills Throwing Uncaught Exceptions in Safari 11.1

[philn5d-ar]

Description

2 Polyfills seem to be the cause of thousands of uncaught exceptions. These end up swamping our logs making it difficult to track other problems.

1. TypeError: setTimeout is not a function position-observer.js:116
2. TypeError: undefined is not an object (evaluating 'Math.round') intersection-observer.install.js:786

Both are quite shocking but also both point to ampproject source. As a publisher, we do not have control over the ad content and technology. Not sure which ad vendor is the culprit either.

Screenshot below.

links to sources:

https://raw.githubusercontent.com/ampproject/amphtml/2107240354000/ads/inabox/position-observer.js
https://cdn.ampproject.org/rtv/012107240354000/v0/amp-intersection-observer-polyfill-0.1.mjs

New Relic breakdown of errors chiefly related to this by platform (30 minute window):

Reproduction Steps

go to https://www.accuradio.com from Safari 11.1
open console
click a channel image to play and launch banner
wait for errors, if no errors yet click genres in left nav to cycle ads (15 second lockout per cycle)

Relevant Logs

No response

Browser(s) Affected

Safari

OS(s) Affected

Mac High Sierra but others as well.

Device(s) Affected

No response

AMP Version Affected

2107240354000

[kristoferbaxter]

Adding @jridgewell and @powerivq to the issue.

Marked as P1 for triage, but this might be higher priority.

[powerivq]

Unable to reproduce the problem on the page on a newer Safari.

@kristoferbaxter Is Safari 11 still a browser AMP maintained support?

[samouri]

@powerivq: we support "works but not perfect" support down to 8.0: https://amp.dev/support/faq/supported-browsers/

[jridgewell]

When going to the site, I just get an access denied:

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.