How to create a plain javascript object

[ZhaoXiangXML]

Summary

I'd like to create rust binding for something like this:

export namespace Math {
    type Vector3 = { "x": number, "y": number, "z": number };
}

So I've add binding like this:

use wasm_bindgen::prelude::*;

#[wasm_bindgen]
extern "C" {
    #[wasm_bindgen(extends = js_sys::Object, js_namespace = Math, js_name = Vector3, typescript_type = "Math.Vector3")]
    #[derive(Debug, Clone, PartialEq, Eq)]
    pub type JsVector3;

    #[wasm_bindgen(constructor, js_class = Vector3)]
    pub fn new() -> JsVector3;

    #[wasm_bindgen(method, getter, js_class = Vector3, js_name = x)]
    pub fn x(this: &JsVector3) -> f64;
    #[wasm_bindgen(method, setter, js_class = Vector3, js_name = x)]
    pub fn set_x(this: &JsVector3, value: f64);

    // ...
}

The problem is I don't know how to create a new JsVector3 object like {x: 1.0, y: 2.0, z: 3.0} in javascript.

I've tried let vec = JsVector3::new() in rust but it won't run as Vector3 is not an actual class in javascript.

Additional Details

I've found this post but I don't know how to cast JsObject to JsVector either.

[jonboj]

The snippet above is for js-import (extern "C"), hence using a javascript class from Rust. In this case Vector3 should be declared in javascript. Maybe export from Rust to javascript rust-export is appropriate instead.