JSON.stringify - workaround for "converting circular structure to JSON"

circularObjStringify

// Assume obj is an object with circular structure
var cache = [];
var str = JSON.stringify(obj, function(key, value) {
  if (typeof value === "object" && value !== null) {
    if (cache.indexOf(value) !== -1) {
      return;
    }
    cache.push(value);
  }
  return value;
});

console.log(str);