RegExp can't match

[git-lt]

source code 61： replacement: new RegExp('background-image:\s+url(\s?(["']?)\s?' + makeRegexp(url) + '\s?\1\s?)[^;]*;', 'gi'),

it can be => replacement: new RegExp('background-image:\s?url(\s?(["']?)\s?' + makeRegexp(url) + '\s?\1\s?)[^;]*;', 'gi'),

css .level-img.active.level1 {background-image:url(../img/grade_icon_numBjOn.png); }

match /background-image:\s+url(\s?(["']?)\s?../img/grade_icon_numBjOn.png\s?\1\s?)[^;]*;/.test('background-image:url("../img/grade_icon_numBjOn.png ");') => false

[git-lt]

imageRegex = new RegExp('background-image:[\s]?url(["']?([\w\d\s!:./-_@].[\w?#]+)["']?)[^;];(?:\s_/_\s_@meta\s_({.})\s*/)?', 'ig');

not match "background:url();"