Javascript Range similar to Python

function range(n,incr) {
return Array.from(new Array(n), (x,i) => (incr==undefined?i:i+incr))
}

// Usage
range(10) //gives [0,1,2,3,4,5,6,7,8,9]
range(10,1) //gives [1,2,3,4,5,6,7,8,9,10]


//One line factorial

function fact(n) {return range(n,1).reduce(function(x,y) { return x*y })}