1478755 - Flash of recommended story in third tile while loading spoc

Status: VERIFIED FIXED

(Firefox :: New Tab Page, defect, P1)

Description

[Scott [:thecount] Downe]

Attachment: sponsored content appears after a normal one.gif

Found in https://bugzilla.mozilla.org/show_bug.cgi?id=1472292

See attachment to get an idea of the issue in action.

What happens is when the stories get fetched, the recs are inserted, then an event is fired to notify of an update https://github.com/mozilla/activity-stream/blob/master/lib/TopStoriesFeed.jsm#L101

When that's done a NEW_TAB_REHYDRATED even is fired which causes us to add the spoc: https://github.com/mozilla/activity-stream/blob/master/lib/TopStoriesFeed.jsm#L468

This is most likely causing the delay. It also looks like this is here to ensure that
1. spocs never delay a rec being shown because there is no guarantee a spoc is going to be added.
2. Waiting for recs to be done before inserting a spoc ensure a rec never loads on top of a spoc.

If we are to fire off adding spocs at the same time to start adding recs, we'll reduce the delay, but need to ensure if we are adding a rec in the third spot, we check to make sure a spoc isn't already there.

Comment 1

[GitHub Bugzilla PR Linker]

Attachment: Link to GitHub pull-request: https://github.com/mozilla/activity-stream/pull/4339

Comment 2

[GitHub Bugzilla PR Linker]

Attachment: Link to GitHub pull-request: https://github.com/mozilla/activity-stream/pull/4356

Comment 3

[[github robot]]

Commit pushed to master at https://github.com/mozilla/activity-stream

https://github.com/mozilla/activity-stream/commit/2389a2237b5085783c0b84eef50ce31fa2317b7d
Bug 1478755 - Ensure spocs load without a flash of rec

Comment 4

[Ed Lee :Mardak]

https://hg.mozilla.org/mozilla-central/rev/332b73bd0c42

Comment 5

[Marius Coman [:mcoman], Ecosystem QA]

I have verified that this issue is no longer reproducible on Windows 10 x64, Arch Linux and Mac 10.13.3 with the latest "Firefox Nightly" (63.0a1 - Build ID 20180902220539) installed. Now the sponsored content is no longer displayed after a normal one.