Any non-trivial JS code is likely to be closely tied to the original platform/runtime for which it was meant, and thus hard to port. (Vs. purely computational)

I have experience of porting JS code from one environment to another. First I was using Delphi Application with MS Active Scripting and MS JScript Engine then moved to nodejs on linux, then back to windows on nodejs, and still have JS code originally written for MS Active Scripting. With nodejs vm module you may create needed context. I also was successfully using socket.io and code on top of it with MS Active Scripting based application by implementing simple WebSocket wrapper to Delphi component.