message: utils/clone: copy array values
diff: -import { plainObject } from './is';
  +import * as is from './is';
  +import * as arr from './arr';
  export default function clone (source) {
  const dest = {};
  +
  for (const prop in source) {
  - if (plainObject(source[prop])) {
  - dest[prop] = clone(source[prop]);
  - } else {
  - dest[prop] = source[prop];
  + const value = source[prop];
  +
  + if (is.plainObject(value)) {
  + dest[prop] = clone(value);
  + }
  + else if (is.array(value)) {
  + dest[prop] = arr.from(value);
  }
  + else {
  + dest[prop] = value;
  }
  + }
  +
  return dest;
  }
  