1 # fast-json-stable-stringify
3 Deterministic `JSON.stringify()` - a faster version of [@substack](https://github.com/substack)'s json-stable-strigify without [jsonify](https://github.com/substack/jsonify).
5 You can also pass in a custom comparison function.
7 [![Build Status](https://travis-ci.org/epoberezkin/fast-json-stable-stringify.svg?branch=master)](https://travis-ci.org/epoberezkin/fast-json-stable-stringify)
8 [![Coverage Status](https://coveralls.io/repos/github/epoberezkin/fast-json-stable-stringify/badge.svg?branch=master)](https://coveralls.io/github/epoberezkin/fast-json-stable-stringify?branch=master)
13 var stringify = require('fast-json-stable-stringify');
14 var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 };
15 console.log(stringify(obj));
21 {"a":3,"b":[{"x":4,"y":5,"z":6},7],"c":8}
28 var stringify = require('fast-json-stable-stringify')
31 ## var str = stringify(obj, opts)
33 Return a deterministic stringified string `str` from the object `obj`.
40 If `opts` is given, you can supply an `opts.cmp` to have a custom comparison
41 function for object keys. Your function `opts.cmp` is called with these
45 opts.cmp({ key: akey, value: avalue }, { key: bkey, value: bvalue })
48 For example, to sort on the object key names in reverse order you could write:
51 var stringify = require('fast-json-stable-stringify');
53 var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 };
54 var s = stringify(obj, function (a, b) {
55 return a.key < b.key ? 1 : -1;
60 which results in the output string:
63 {"c":8,"b":[{"z":6,"y":5,"x":4},7],"a":3}
66 Or if you wanted to sort on the object values in reverse order, you could write:
69 var stringify = require('fast-json-stable-stringify');
71 var obj = { d: 6, c: 5, b: [{z:3,y:2,x:1},9], a: 10 };
72 var s = stringify(obj, function (a, b) {
73 return a.value < b.value ? 1 : -1;
81 {"d":6,"c":5,"b":[{"z":3,"y":2,"x":1},9],"a":10}
86 Pass `true` in `opts.cycles` to stringify circular property as `__cycle__` - the result will not be a valid JSON string in this case.
88 TypeError will be thrown in case of circular object without this option.
93 With [npm](https://npmjs.org) do:
96 npm install fast-json-stable-stringify
102 To run benchmark (requires Node.js 6+):
109 fast-json-stable-stringify x 17,189 ops/sec ±1.43% (83 runs sampled)
110 json-stable-stringify x 13,634 ops/sec ±1.39% (85 runs sampled)
111 fast-stable-stringify x 20,212 ops/sec ±1.20% (84 runs sampled)
112 faster-stable-stringify x 15,549 ops/sec ±1.12% (84 runs sampled)
113 The fastest is fast-stable-stringify
117 ## Enterprise support
119 fast-json-stable-stringify package is a part of [Tidelift enterprise subscription](https://tidelift.com/subscription/pkg/npm-fast-json-stable-stringify?utm_source=npm-fast-json-stable-stringify&utm_medium=referral&utm_campaign=enterprise&utm_term=repo) - it provides a centralised commercial support to open-source software users, in addition to the support provided by software maintainers.
124 To report a security vulnerability, please use the
125 [Tidelift security contact](https://tidelift.com/security).
126 Tidelift will coordinate the fix and disclosure. Please do NOT report security vulnerability via GitHub issues.
131 [MIT](https://github.com/epoberezkin/fast-json-stable-stringify/blob/master/LICENSE)