xss test.js

var isPollutedObject = (data)=>{

    // simple string wala use case
    if (typeof data === 'string') {
        if (data.includes('BAD')) {
            return true;
        } else {
            return false;
        }
    }

    // Object wala use case
    if (typeof data === 'object') {
        return !!Object.keys(data).find(key=>isPollutedObject(data[key]));
    }

    return false;

}

console.log(isPollutedObject({}));
console.log(isPollutedObject({
    a: true,
    b: {
        c: 'good',
        d: {
            e: "yes"
        }
    }
}));
console.log(isPollutedObject({
    a: true,
    b: {
        c: 'goodBAD',
        d: {
            e: "yes"
        }
    }
}));