Get nested prop values in JS proxy

get-nested-prop-values-in-js-proxy.js

// via https://stackoverflow.com/questions/46005706/get-the-path-to-the-accessed-value-in-a-nested-object
function wrap(o, fn, scope = []) {
  const handler = {
    set(target, prop, value, receiver) {
      fn('set value in scope: ', scope.concat(prop))
      target[prop] = value
      return true
    },
    get(target, prop, receiver) {
      fn('get value in scope: ', scope.concat(prop))
      return target[prop]
    },
    ownKeys() {
      fn('keys in scope: ', scope)
      return Reflect.ownKeys(o)
    }
  }

  return new Proxy(
    Object.keys(o).reduce((result, key) => {
      if (isObject(o[key])) {
        result[key] = wrap(o[key], fn, scope.concat(key))
      } else {
        result[key] = o[key]
      }
      return result
    }, {}),
    handler
  )
}

function isObject(obj) {
  return typeof obj === 'object' && !Array.isArray(obj)
}

const obj = wrap({
  a0: {
    a1: {
      a2: 0
    },
    b1: {
      b2: 0
    }
  },
  b0: 0
}, console.log)


// set value:
obj.b0 = 1

// get value:
console.log('value: ' + obj.a0.a1.a2)

// list keys:
console.log('keys: ', Object.keys(obj.a0))