join-deep/dist/esm/index.js

Deep join an array

import reduceDeep from 'reduce-deep';
export default function joinDeep(array, sep) {
    let hasJoined = false;
    return reduceDeep(array, (memo, value)=>{
        if (hasJoined) memo += sep;
        else hasJoined = true;
        memo += value === undefined ? '' : value;
        return memo;
    }, '');
}