The code most likely works in spite of the error message. The error you are getting is really just a Typescript (code parsing mechanism) syntax notification. Is your code not working?
If you feel that there is a bug, then your question should be directed to Wix Customer Care . Understand that this forum is not a support site, and is not monitored for bugs or system issues. Please report bugs to Wix Customer Care to ensure timely handling of your problem. They track and monitor all incoming issues and will escalate bugs to product teams.