Try re-installing now. It looks like the npm version of esmangle is broken (uses an old estraverse). Since EspruinoTools includes esmangle anyway, we now just use that version instead and it seems to work ok.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Wow,that is a strange one.
Try re-installing now. It looks like the npm version of esmangle is broken (uses an old estraverse). Since EspruinoTools includes esmangle anyway, we now just use that version instead and it seems to work ok.