Exploring Proxies & [Symbol.toPrimitive]

test.js

// http://www.ecma-international.org/ecma-262/6.0/#sec-symbol.toprimitive

let base = {
  [Symbol.toPrimitive] : hint => {
    console.log(`toPrimitive hint: ${hint}`)
    return 1;
  },
  valueOf: () => 2,
  toString: () => '3',
};

let myProxy = new Proxy(base, {
  get : function (target, name) {
    if (!(name in target)) {
      return 'not found'
    }

    return target[name]
  }
});

console.log('--- number')
console.log(+myProxy)

console.log('--- string')
console.log(`${myProxy}`)

console.log('--- default')
console.log(myProxy + "")

console.log('--- N/A - doesn\'t call toPrimitive')
console.log(myProxy.toString())