math-utils-william/lib/index.js

function getSum(){
    var arr = Array.prototype.slice.apply(arguments),
        sum = 0 ;
    for(var i = 0 ; i < arr.length ; i++ ){
        if( typeof arr[i] === 'number'){
            sum+=arr[i];
            continue;
        }
        throw new Error('some arguments is not a "number"')
    }
    return sum;
}
const utils = {
    getSum
}

module.exports = utils