SOURCE

let arr = ['1.0.1','1.0.2','1.0.12','1.0.8','1.0.100','1.0.1(to do)']
arr.sort((a,b)=>{
    let aver = a.split('.')
    let bver = b.split('.')
    //console.log(aver)
    for(let i=0;i < aver.length;i++){
        let va = parseInt(aver[i])
        let vb = parseInt(bver[i])
        if (va != vb){
            return va - vb
        }
    }
    return 0
})

console.log(arr)

let maxVer = arr[arr.length-1]
let vers = maxVer.split('.')
let nextv = parseInt(vers[vers.length-1])+1
vers[vers.length-1]=nextv
let newVer = ''
vers.forEach(v=>{
    if (newVer) newVer += `.`
    newVer += `${v}`
})

console.log(newVer)