This dependency recursively flattens an array:
var flatten = require("arr-flatten");
flatten([1, [2, [3, [4]], 5], 6]);
//=> [1, 2, 3, 4, 5, 6]You can achieve the same functionality natively in JavaScript using the flat method with Infinity as the depth argument:
const array = [1, [2, [3, [4]], 5], 6];
const flattened = array.flat(Infinity); // [1, 2, 3, 4, 5, 6]This is supported in all modern JavaScript environments