dirty.js - dirty marking for any JS object

dirty.js

/*
Released under MIT License
Copyright 2020 Gordon Brander
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
const $dirty = Symbol('dirty keys')

// Get or create set of dirty keys on object.
export const dirtyKeys = object => {
  if (object[$dirty] == null) {
    object[$dirty] = new Set()
  }
  return object[$dirty]
}

// Is object dirty?
export const isDirty = object => dirtyKeys(object).size > 0

// Is key on object dirty?
export const isKeyDirty = (object, key) => dirtyKeys(object).has(key)

// Clean object
export const clean = object => {
  dirtyKeys(object).clear()
  return object
}

// Set value at key, and mark dirty if changed
export const set = (object, key, value) => {
  if (object[key] !== value) {
    dirtyKeys(object).add(key)
    object[key] = value
  }
  return object
}

const handler = {set}

// Create a proxy for object, which will transparently handle dirty marking
// for any property set.
export const proxy = object => new Proxy(object, handler)