TextEncoder and TextDecoder are added as globals in node11.
Maybe it is possible to use these for jsdom?

https://developer.mozilla.org/en-US/docs/Web/API/TextDecoder
https://developer.mozilla.org/en-US/docs/Web/API/TextDecoder

https://nodejs.org/api/globals.html#globals_textdecoder
https://nodejs.org/api/globals.html#globals_textencoder

I made a change in jest to support these in jest-environment-node. jestjs/jest#8022 I can make simmilar change in jsdom but I am not sure were it should be done.