結論structuredClone
を使う
const obj = {
sample: "sample",
};
const obj2 = structuredClone(obj);
console.log(obj);
// { sample: "sample" }
console.log(obj2);
// { sample: "sample" }
obj.sample = "aiueo";
console.log(obj);
// { sample: "aiueo" }
console.log(obj2);
// { sample: "sample" }