deep clone

clone.ts

type Fn = (...args: unknown[]) => unknown;

// 取出 T 中静态 keys
type StaticKeys<T> = {
    [K in keyof T]: T[K] extends Fn ? never : K
}[keyof T]

// 去除 T 里面的函数
type StaticObject<T> = Pick<T, StaticKeys<T>>

/**
 * 深度拷贝
 * @param obj
 * @returns
 */
export function cloneObj<T>(obj: T): StaticObject<T> {
    if (typeof obj !== 'object') return obj;

    const keys = Object.keys(obj) as Array<keyof T>;

    const cloned: any = {}; // ts 这里没法定义

    keys.forEach(k => {
        const value = obj[k];
        if (typeof value === 'object') {
            cloned[k] = cloneObj(obj[k]);
        } else {
            cloned[k] = obj[k];
        }
    });

    return cloned;
}

console.log(
    cloneObj({ a: { b: { c: 123 } } }).a.b
);

console.log(
    cloneObj([{ a: { b: { c: 123 } } }])[0].a.b
);

console.log(
    cloneObj(new class { a = 1; b = 2; c = 3 })
);