1620670 - Slight jank on collection dismiss

Status: VERIFIED FIXED

(Firefox :: New Tab Page, enhancement)

Description

[Scott [:thecount] Downe]

If you dismiss a collection, it does a dismiss action on each item.

This does create a bit of jank as you see the items disappear.

Comment 1

[Scott [:thecount] Downe]

Attachment: Bug 1620670 - Remove dismiss jank for collections.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6a869c8f85e8
Remove dismiss jank for collections. r=gvn

Comment 3

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/6a869c8f85e8

Comment 4

[Robert Martin [:romartin], Ecosystem QA]

I have tested this enhancement using the following scenario:

[Prerequisites]:

• Have the last affected build version of Firefox Nightly 75.0a1 (Build ID: 20200307093221) installed.
• Have the first fixed build version of Firefox Nightly 75.0a1 (Build ID: 20200307213339) installed.

[Steps to reproduce]:

1. Capture the “Running Time” of the “about:newtab” page after closing the “Collection Stories” section using “Firefox Profiler” on both the Firefox Nightly 75.0a1 builds.
2. Repeat the above test several times.
3. Compare the results.

[Actual result]:

• It seems that there is a slight difference. The last affected Firefox build needs approximately 3,400 ms of “Running time” while the first fixed Firefox build needs approximately 2,800 ms of “Running time”.

[Notes]:

• I’ve repeated the first step several times for a more accurate result.
• I’ve tested on Windows 10 x64, macOS 10.15.1, and Ubuntu 18.04 x64.

Given the above, @Scott, do you think that this is enough verification from our side in order to mark this as VERIFIED?

Comment 5

[Scott [:thecount] Downe]

@Robert, yeah that's probably a result of this work. I should have added more detailed steps to test on this one.

Essentially what's happening before the patch, when you dismiss, it fires a dismiss on each card, which you can visually see each card go away 1 by 1, which is visually pretty janky.

With the patch, I remove the visual collection at once, and the removal of each card is just in the data, not in the UI.

This would create a situation where we ask the browser to do less rendering, which is probably why you see less running time. So that's a significant verification, but probably also a lot of work to verify it, as I think you can verify it visually too much faster. I dunno how long it takes to verify multiple attempts to get accurate results. It's not wasted either, because it's a much deeper verification.

To verify it visually, when you dismiss, watch how the collection section goes away. Does it blip away in one go right after clicking, or do you see it incrementally go away card by card.

Both ways work, so I would call this verified.

Comment 6

[Robert Martin [:romartin], Ecosystem QA]

Thank you @Scott!

Based on comment 5 I have verified that there is a noticeable visual difference between the way the section is dismissed in the two Firefox Builds:

• Using the latest affected Firefox build, I can see that each card is dismissed one after another followed by the section being completely dismissed.
• Using the first fixed Firefox Build, I can see that all the cards and the section is dismissed instantly.

Given the above and the checks mentioned in comment 4 I mark this issue as VERIFIED.