[amp-next-page] v1.0 not working if in first viewport

[noodles]

#29855 What's the issue?

amp-next-page does not work at all if the component appears in the first viewport

How do we reproduce the issue?

Create an AMP page with with the amp-next-page component but only add enough text/content so that the amp-next-component is visible in the first viewport.

v1.0 issue example

Adding more content to push the amp-next-page component out of the first viewport will fix the isse;

v1.0 fix example

What browsers are affected?

All browsers

[nainar]

Related #29936

[dmanek]

@nainar @wassgha this unit test https://github.com/ampproject/amphtml/blob/master/extensions/amp-next-page/1.0/test/test-amp-next-page.js#L332 leads me to believe that amp-next-page was designed to be displayed only when the user scrolls below the first viewport. Do we want to support this use case?

[wassgha]

That's correct behavior. This is to avoid layout shift

[dmanek]

Closing this issue as WAI.