a ref of an array is marked as readonly

[posva]

See https://jsfiddle.net/bqct135h/

isReadonly(ref([])) // true

But it should be false: SFC Playground

[webfansplz]

readonly() is provided as API alignment with Vue 3 on type-level only. Use isReadonly() on it or it's properties can not be guaranteed.

In @vue/composition-api, Use isReadonly() always return true for reactive object , because:

export function createRef<T>(options: RefOption<T>, readonly = false) {
  const r = new RefImpl<T>(options)
  const sealed = Object.seal(r)
  readonlySet.set(sealed, true) // always trigger
  return sealed
}