JSFiddle - React, Tailwind, and code Playground

JavaScript

function range(start, end, step) {
    if (typeof step === 'undefined') {
        step = 1;
    }
    
    if (typeof start === 'undefined' || typeof end === 'undefined') {
        throw TypeError('Must have start and end');
    }
    
    var ret = [];
    for (var i = start; i <= end; i += step) {
        ret.push(i);
    }
    
    return ret;
};

// source: http://stackoverflow.com/a/6274381/520857
function shuffle(o) { //v1.0
    for(var j, x, i = o.length; i; j = Math.floor(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
    return o;
};

function getNonRepeatingRand(min, max, num) {
    var arr = shuffle(range(min, max));
    return arr.slice(0, num-1);
}
console.log(getNonRepeatingRand(1,1000,7));