A simple implementation of flatten

flatten.js

const isArray = Array.isArray;
const reducer = (acc, ele) => {
    const elements = isArray(ele) ? flatten(ele) : ele;
    return acc.concat(elements);
};
const reduce = (arr) => arr.reduce(reducer, []);
const flatten = arr => isArray(arr) ? reduce(arr) : arr;

module.exports = flatten;

flatter.md

FLATTEN

This code is a simple implementation of the flatten function for Nodejs. There are no external dependencies.

TEST

the assert library is used for testing to avoid external dependencies. To test the function simple run node test.js with node 6.x.x

USAGE

If you want to use the function, just import the library:

const flatten = require('./flatten');

console.log(flatten([1,2,[3]])

test.js

const { deepEqual } = require('assert');

const flatten = require('./flatten');

deepEqual(1, flatten(1));
deepEqual([1,2,3], flatten([1,2,3]));
deepEqual([1,2,3], flatten([1,[2],3]));
deepEqual([1,2,3,4], flatten([1,2,[3,[4]]]));
deepEqual([1,2,3,4,5,6,7], flatten([1,2,[3,[4,[5,6,7]]]]));
deepEqual(['a',{},1,1.4], flatten([[[[['a',{},1,1.4]]]]]));

console.log('All Test Passed');