jormungandr-bite/packages/backend/src/misc/clone.ts

// structredCloneが遅いため
// SEE: http://var.blog.jp/archives/86038606.html

type Cloneable =
	| string
	| number
	| boolean
	| null
	| { [key: string]: Cloneable }
	| Cloneable[];

export function deepClone<T extends Cloneable>(x: T): T {
	if (typeof x === "object") {
		if (x === null) return x;
		if (Array.isArray(x)) return x.map(deepClone) as T;
		const obj = {} as Record<string, Cloneable>;
		for (const [k, v] of Object.entries(x)) {
			obj[k] = deepClone(v);
		}
		return obj as T;
	} else {
		return x;
	}
}