🚨 Error: Cannot read property 'getBoundingClientRect' of undefined

[ampprojectbot]

Details

Error report: link
First seen: Nov 19, 2020
Frequency: ~ 945/day

Stacktrace

Error: Cannot read property 'getBoundingClientRect' of undefined
    at getBoundingClientRect (extensions/amp-base-carousel/0.1/dimensions.js:58:16)
    at getDimension (extensions/amp-base-carousel/0.1/dimensions.js:73:23)
    at getCenter (extensions/amp-base-carousel/0.1/dimensions.js:97:6)
    at getPosition (extensions/amp-base-carousel/0.1/dimensions.js:155:16)
    at getPercentageOffsetFromAlignment (extensions/amp-base-carousel/0.1/carousel.js:1241:25)
    at restoreScrollStart_ (extensions/amp-base-carousel/0.1/carousel.js:1218:6)
    at mutator (src/service/mutator-impl.js:227:8)
    at callback (src/service/vsync-impl.js:470:16)
    at callTask_ (src/service/vsync-impl.js:426:8)

Notes

@rsimha modified extensions/amp-base-carousel/0.1/dimensions.js:58-58 in #21212 (May 16, 2019)
Sepand Parhami modified extensions/amp-base-carousel/0.1/dimensions.js:67-86 in #20389 (Jan 17, 2019)
Sepand Parhami modified extensions/amp-base-carousel/0.1/carousel.js:1216-1229 in #20293 (Jan 16, 2019)
@powerivq modified src/service/mutator-impl.js:225-227 in #26638 (Feb 12, 2020)
@jridgewell modified src/service/vsync-impl.js:470-471 in #20836 (Feb 14, 2019)

Seen in:

• 11-25 Stable (2111+3)
• 12-23 Control (2217)
• 12-23 Stable (2217)
• 12-30 Experiment-A (1722)
• +6 more

Possible assignees: @powerivq, @jridgewell

/cc @ampproject/release-on-duty

[micajuine-ho]

Took a quick peak at the error links--all of the carousels on those pages seem to have the same structure:

<p>
  <amp-carousel>
    <div class="ampforwp-gallery-item amp-carousel-container"><amp-img></amp-img></div>
    <div class="ampforwp-gallery-item amp-carousel-container"><amp-img></amp-img></div>
    <div class="ampforwp-gallery-item amp-carousel-container"><amp-img></amp-img></div>
  </amp-carousel>
</p>

<p> tags are only allowed to have "paragraph content" within them (all other tags, including divs, will get stripped by the browser). This causes all the carousels to have no slides--which probably causes the error found above.

This is essentially the same problem as #31251.

Maybe this sort of developer error can be fixed with wider documentation for 'common issues'?

/cc @ampproject/wg-components

[micajuine-ho]

Closed via #31945