Order of conditions causes unnecessary Reflow

[ksmwsk@…]

When profiling a web application which features live resizing with its components i found a spot in the jQuery code causing unnecessary reflow.

return elem.offsetWidth === 0 && rdisplayswap.test( jQuery.css( [...]

if i change this so that the test for the display value will be the first one:

return rdisplayswap.test( jQuery.css( [...])) && elem.offsetWidth === 0

Now offsetWidth seems to take much more performance than retrieving the display property and testing it with the regexp.

If this will be confirmed as a valid issue, i would love to contribute this change via github.

[dmethvin]

Awesome, great catch! We'd love a pull request on this.

[anonymous]

Okay i will add a pull request today.

[ksmwsk@…]

I added a pull request here:

​https://github.com/jquery/jquery/pull/1560

[Christian Kosmowski]

Dimensions: Reverse a check to avoid potential reflows

Fixes #14979 Closes gh-1560

Changeset: 1ca84214cc89d9e5f8af12b18b34426fc91b1b08