Will give you the current state as an integer

var Lifecycle = require("FuseJS/Lifecycle");

console.log(Lifecycle.state === Lifecycle.BACKGROUND);
console.log(Lifecycle.state === Lifecycle.FOREGROUND);
console.log(Lifecycle.state === Lifecycle.INTERACTIVE);

Location

Namespace
FuseJS
Package
FuseJS 1.11.2

Returns

int