node null check example

gistfile1.js

var http = require('http');

var nullList = [];

function process(key,value) {
    if(value === null || value === undefined){
      nullList.push({
          'key':key,
          'value': value
      })
    }
}

function traverse(o,func) {
    for (var i in o) {
        func.apply(this,[i,o[i]]);
        if (o[i] !== null && typeof(o[i])=="object") {
            traverse(o[i],func);
        }
    }
}

http.globalAgent.maxSockets = undefined;
traverse(http, process);
console.log(nullList);

//output
//[ { key: 'domain', value: null },
//{ key: 'maxSockets', value: undefined } ]