ljharb
listify 
Turn an array into a list of comma-separated values, appropriate for use in an English sentence.
Example
var listify = require('listify');
assert(listify([1, 2]) === '1 and 2');
assert(listify([1, 2, 3]) === '1, 2, and 3');
assert(listify([1, 2, 3, 4]) === '1, 2, 3, and 4');
assert(listify([1, 2, 3], { separator: '… ' }) === '1… 2… and 3');
assert(listify([1, 2, 3], { finalWord: false }) === '1, 2, 3');
assert(listify([1, 2, 3], { separator: '… ', finalWord: 'or' }) === '1… 2… or 3');Tests
Simply clone the repo, npm install, and run npm test