You'd have to google it - as far as I remember you can use a command-line switch to disable WASM
edit: what I did for heatshrink in the browser might work: https://github.com/gfwilliams/heatshrink-js
But I don't know whether your wrapped emscripten code can be squished down further with some options
@Gordon started
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.
You'd have to google it - as far as I remember you can use a command-line switch to disable WASM
edit: what I did for heatshrink in the browser might work: https://github.com/gfwilliams/heatshrink-js
But I don't know whether your wrapped emscripten code can be squished down further with some options