Error: Cannot call method 'requestMeasure' of undefined

[adelinamart]

@aghassemi can you check the following production error. Thanks.

Error: Impossible d’obtenir la propriété « requestMeasure » d’une référence null ou non définie
at (https://raw.githubusercontent.com/ampproject/amphtml/1809142227020/src/focus-history.js:120)
at (https://raw.githubusercontent.com/ampproject/amphtml/1809142227020/src/service/viewport/viewport-impl.js:559)
at animateScrollIntoViewInternal_ (https://raw.githubusercontent.com/ampproject/amphtml/1809142227020/src/service/viewport/viewport-impl.js:539)

Version
011809142227020

https://pantheon.corp.google.com/errors/CP6dwsLQn4P4uQE?service=default-cdn-1p&time=P1D&project=amp-error-reporting

[aghassemi]

reassigning to @jridgewell

[ampprojectbot]

This is a high priority issue but it hasn't been updated in awhile. @jridgewell Do you have any updates?

[ampprojectbot]

This is a high priority issue but it hasn't been updated in awhile. @jridgewell Do you have any updates?

[ampprojectbot]

This is a high priority issue but it hasn't been updated in awhile. @jridgewell Do you have any updates?

[Enriqe]

This is still being logged in version 1901302225410

Error: Cannot call method 'requestMeasure' of undefined
at (https://raw.githubusercontent.com/ampproject/amphtml/1901242049580/src/focus-history.js:121)
at innerHeight (https://raw.githubusercontent.com/ampproject/amphtml/1901242049580/src/service/viewport/viewport-impl.js:833)
at leaveFullOverlayMode (https://raw.githubusercontent.com/ampproject/amphtml/1901242049580/src/service/viewport/viewport-impl.js:775)

[samouri]

@jridgewell / @choumx: this is still marked P1 and yet hasn't had activity since 2019. Is there action for us to take here?

I see this recent message in our error logs:

version: "011912180046560"

2020-01-14 15:36:04.216 EST
Error: Cannot read property 'requestMeasure' of undefined
  at requestMeasure (https://raw.githubusercontent.com/ampproject/amphtml/1912180046560/src/service/resources-impl.js:627:10) 
  at https://raw.githubusercontent.com/ampproject/amphtml/1912180046560/src/service/vsync-impl.js:470:16 
  at callTask_ (https://raw.githubusercontent.com/ampproject/amphtml/1912180046560/src/service/vsync-impl.js:426:8) 
  at handler_ (https://raw.githubusercontent.com/ampproject/amphtml/1912180046560/src/pass.js:109:4) 
  at pass_ (https://raw.githubusercontent.com/ampproject/amphtml/1912180046560/src/pass.js:55:6) 
  at https://raw.githubusercontent.com/ampproject/amphtml/1912180046560/src/service/timer-impl.js:83:8

[jridgewell]

Wanna investigate it? 😉

[dreamofabear]

https://github.com/ampproject/amphtml/blob/1912180046560/src/service/resources-impl.js#L627

Looks like there's more than one cause. How prominent is the error? E.g. top N.

[samouri]

While there are a few others, this is the most prominent cause of this error by far. In terms of this error vs. others, this one is pretty low on the occurrences list.

The problem snippet is this:

const ampElements = element.getElementsByClassName('i-amphtml-element');
for (let i = 0; i < ampElements.length; i++) {
  const r = Resource.forElement(ampElements[i]);
  r.requestMeasure(); // <--- `r` is undefined
}

While getElementsByClassName returns a live-list, I don't think an element removal (making ampElements[i] undefined), could be a cause for this. Mostly because no other code could run in between those two lines.

So the culrpit must be Resource.forElement returning undefined for an element that has a classname i-amphtml-element. The file that adds that classname and manages adding/removing the resource is custom-element.js. What seems most likely to me is that a disconnect event is removing the resource without removing the classname.

[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.