Javascript Deep Merge (Recursive)

deep-merge.js

// Merge multiple objects
function deepMerges(...objs) {
    return objs.reduce((a, b) => deepMerge(a,b), {})
}

// Merge two objects
function deepMerge (one, two) {
    if (Array.isArray(one) && Array.isArray(two)) {
        return one.concat(two)
    }
    if (typeof two !== 'object' || typeof one !== 'object'|| one === undefined ) {
        return two
    }
    if (typeof one === 'object' && typeof two === 'object') {
        const newObj = Object.assign({}, one)
        for (let key of Object.keys(two)) {
            newObj[key] = deepMerge(newObj[key], two[key])
        }
        return newObj
    }
}