Enumerability and ownership of Symbol properties

playground.js

const s = Symbol()
const o = { [s]: 1 }

o.hasOwnProperty(s)
//-> true

Object.getOwnPropertyNames(o)
//-> []

Object.getOwnPropertySymbols(o)
//-> [Symbol()]

o.propertyIsEnumerable(s)
//-> true

Object.keys(o)
//-> []

Object.entries(o)
//-> []

Object.assign({}, o)[s]
//-> 1