BF to Javascript convert and interpreter

function bf(code) {
    let _bf = code.replace(/[^+\-<>\[\].]/g, "").replace(/([+\-<>])\1{0,255}/g, g => g[0] + String.fromCharCode(g.length));
    let js = "var s='';var t={};var p=0;for(var i=0;i<30000;i++)t[i]=0;";
    let ci = 0;
    for (let i = 0; i < _bf.length; i++) {
        switch (_bf[i]) {
            case "+":
            case "-":
                js += "t[p]" + _bf[i] + "=" + _bf.charCodeAt(++i) + ";";
                break;
            case ">":
                js += "p+=" + _bf.charCodeAt(++i) + ";";
                break;
            case "<":
                js += "p-=" + _bf.charCodeAt(++i) + ";";
                break;
            case "[":
                js += "for(var c" + ci + "=0;c" + ci + "<1024;c" + ci + "++){";
                js += "if(!t[p])break;";
                ci++;
                break;
            case "]":
                ci--;
                js += "}";
                break;
            case ".":
                js += "s+=String.fromCharCode(t[p]);";
                break;
        }
    }
    js += "return s;";
    return new Function(js)();
}