getting javascript value of random type

mixValue.js

// special Javascript values
const specials = [null, true, false, undefined, NaN, 1/0, -1/0, -0];

function getMixValue(){
    return randIndex([
            randSpecial,
            randInt,
            randFloat,
            randStr,
            randArray,
            randObject,
        ])();
}

function randIndex(array){
    return array[Math.random()*array.length|0];
}

function randSpecial(){
    return specials[(Math.random()*Math.random()*specials.length)|0];
}


function randInt(){
    return Math.random()*Math.pow(2,32)|0;
}

function randFloat(){
    return Math.random()/Math.random() - Math.random()/Math.random();    
}

function randChar(){
    return String.fromCharCode(32+ Math.random()*64);
}

function randStr(avgLen = 5){
    var str = '';
    while(Math.random() > 1/(avgLen+1)){
        str += randChar();
    }
    return str;
}


function randArray(avgLen = 2){
    var arr = [];
    while(Math.random() > 1/(avgLen+1)){
        arr.push(getMixValue());
    }
    return arr;
}

function randKey(){
    return randChar() + randStr(8);
}


function randObject(avgLen = 2){
    var obj = {};
    while(Math.random() > 1/(avgLen+1)){
        obj[randKey()] = getMixValue();
    }
    return obj;
}