1503347 - Flex item sizing property UI doesn't report the right CSS property values when !important is used

Status: VERIFIED FIXED

(DevTools :: Inspector, defect, P2)

Description

[Patrick Brosset <:pbro>]

Attachment: Screen Shot 2018-10-30 at 18.21.50.png

Steps:

- Load this URL in Firefox nightly: data:text/html,<style>.container{display:flex;}.item{flex-grow:1 !important;} .item {flex-grow:0}</style><div class="container"><div class="item">item</div></div>
- Open the inspector
- Select the <div.item> element in the inspector
- Look at the Flex item accordion of the Layout sidebar panel

Actual:

The "Flexibility" section says "flex-grow:0;"

Expected:

It should say "flex-grow:1;" because that's what the actual value for this property is.

The problem is that the flexbox inspector attempts to find "authored" styles to show the actual properties that were defined by the author.
In doing this, it loops through all rules matching the element and stops as soon as it finds the property with the right name.
The problem with this is that even if flex-grow:0 appears first, it actually does not match, because of an !important property that appears in a lower specificity rule.

Comment 1

[Patrick Brosset <:pbro>]

(In reply to Patrick Brosset <:pbro> from comment #0)
> It should say "flex-grow:1;" because that's what the actual value for this
> property is.
Or, really it should say "flex-grow: 1 !important;"

Comment 2

[Micah [:mtigley] (she/her)]

Attachment: Bug 1503347 - Modify the Flex Item actor to consider CSS rules using the important keyword. r=gl

Comment 3

[Micah [:mtigley] (she/her)]

Try server results: https://treeherder.mozilla.org/#/jobs?repo=try&revision=5b0c5b1754029eebe6fd073a81ec7d51cfd8aadd

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/df86262bfccd
Modify the Flex Item actor to consider CSS rules using the important keyword. r=pbro

Comment 5

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/df86262bfccd

Comment 6

[Cristian Comorasu, QA [:ccomorasu], Releae Desktop QA - Please contact [e-mail]]

I reproduced this issue using 65.0a1(2018-10-30), on Windows 10 x64.
I can confirm this issue is fixed, I verified using Fx 65.0b11 on Windows 10 x64, macOS 10.14.3 and Ubuntu 16.04 LTS.
Cheers!