fix: factor rgbExtractRegexp out of the loop

Author: aminya

lib/dom-styles-reader.js

@@ -133,6 +133,7 @@ export default class DOMStylesReader {
 //    ##     ## ######## ######## ##        ######## ##     ##  ######
 
 const dotRegexp = /\.+/g
+const rgbExtractRegexp = /rgb(a?)\((\d+), (\d+), (\d+)(, (\d+(\.\d+)?))?\)/
 
 /**
  * Computes the output color of `value` with a rotated hue defined
@@ -144,7 +145,7 @@ const dotRegexp = /\.+/g
  * @access private
  */
 function rotateHue (value, filter) {
-  const match = value.match(/rgb(a?)\((\d+), (\d+), (\d+)(, (\d+(\.\d+)?))?\)/)
+  const match = value.match(rgbExtractRegexp)
   let [, , r, g, b, , a] = match
 
   let [, hue] = filter.match(/hue-rotate\((\d+)deg\)/)