issymboltests if something is a Symbol. Works with either native Symbol or polyfill Symbol.
npm install --save issymbol
const issymbol = ;// works with any native Symbol implementation;// → true// also works with your favourite polyfillconst core = ;;// → true// returns false any input that is not a Symbol;// → false
issymbol originated from https://github.com/medikoo/es6-symbol/.