Example of using NativeState to create a class with native data and methods.

native-state-example.js

// Call into a native function that returns an object with all native 
// functions.
let $natives = getNativeFuncs();

function MyClass(a, b) {
    this.a = a;
    this.b = b;
    // The following call performs the native initialization. It creates a 
    // C++ NativeState instance, initializes it with whatever it needs, and
    // calls jsi::Object::setNativeState() on the object to attach it.
    $natives.initMyClass(this);
}

// Attach the native methods like regular JS methods.
// Each native method when invoked will call jsi::Object::getNativeState()
// (checking whether it exists and is the correct C++ class) and then do 
// whatever it needs to do.
MyClass.prototype.method1 = $natives.method1;
MyClass.prototype.method2 = $natives.method2;