Previously, various inputs other than non-negative integers would
produce incorrect results.
Added type-checking on input, returning false for anything other than
non-negative integers.
Also clarified in docs.
PR-URL: https://github.com/nodejs/node/pull/15567
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
