#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)@I18n[\s]class ([A-Za-z]*) extends React.Component {([\s\S]*)}[\s]*$"
Local $sString = ""
Local $sSubst = "\nclass $1 extends React.Component {$2}\n\nexport default I18n($1);"
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm