Create an array of unique values, in order, from the input arrays
$ npm install --save array-union
const arrayUnion = require('array-union'); arrayUnion([1, 1, 2, 3], [2, 3]); //=> [1, 2, 3] arrayUnion(['foo', 'foo', 'bar'], ['foo']); //=> ['foo', 'bar']
MIT © Sindre Sorhus