Web-c: in WheelHandler, event["path"] is always undefined

[joanise]

This code does not work:

read-along.tsx function wheelHandler():

      if (
        event["path"][0].classList.contains("sentence__word") ||
        event["path"][0].classList.contains("sentence__container") ||
        event["path"][0].classList.contains("sentence")
      ) {

because event["path"] is always undefined.

Every time I use my mouse's wheel, I get this exception in a read-along on EastCree.org:

and this one serving from my own computer:

If that logic is sometimes true, then it should be

      if (
        event["path"] && (
        event["path"][0].classList.contains("sentence__word") ||
        event["path"][0].classList.contains("sentence__container") ||
        event["path"][0].classList.contains("sentence")
        )
      ) {

but inspecting the contents of event through console.log(event), I'm not figuring out what this was trying to capture. Maybe event.view or some such?