深拷贝

/**
 * 深拷贝
 */
export function deepClone(val: any): any {
  if (Object.prototype.toString.call(val) === '[object Object]') {
    const obj: any = {}
    for (const key in val) {
      obj[key] = deepClone(val[key])
    }
    return obj
  } else if (Array.isArray(val)) {
    return val.map(item => deepClone(item))
  } else {
    return val
  }
}