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Package detail

json-stringify-safe

isaacs104.4mISC5.0.1TypeScript support: definitely-typed

Like JSON.stringify, but doesn't blow up on circular refs.

json, stringify, circular, safe

readme

json-stringify-safe

Like JSON.stringify, but doesn't throw on circular references.

Usage

Takes the same arguments as JSON.stringify.

var stringify = require('json-stringify-safe');
var circularObj = {};
circularObj.circularRef = circularObj;
circularObj.list = [ circularObj, circularObj ];
console.log(stringify(circularObj, null, 2));

Output:

{
  "circularRef": "[Circular]",
  "list": [
    "[Circular]",
    "[Circular]"
  ]
}

Details

stringify(obj, serializer, indent, decycler)

The first three arguments are the same as to JSON.stringify. The last is an argument that's only used when the object has been seen already.

The default decycler function returns the string '[Circular]'. If, for example, you pass in function(k,v){} (return nothing) then it will prune cycles. If you pass in function(k,v){ return {foo: 'bar'}}, then cyclical objects will always be represented as {"foo":"bar"} in the result.

stringify.getSerialize(serializer, decycler)

Returns a serializer that can be used elsewhere. This is the actual function that's passed to JSON.stringify.

Note that the function returned from getSerialize is stateful for now, so do not use it more than once.

changelog

Unreleased

  • Fixes stringify to only take ancestors into account when checking circularity.
    It previously assumed every visited object was circular which led to false positives.
    Uses the tiny serializer I wrote for Must.js a year and a half ago.
  • Fixes calling the replacer function in the proper context (thisArg).
  • Fixes calling the cycleReplacer function in the proper context (thisArg).
  • Speeds serializing by a factor of Big-O(h-my-god-it-linearly-searched-every-object) it had ever seen. Searching only the ancestors for a circular references speeds up things considerably.